This isn’t one that lends itself to an easy description, or a slick way of introducing it, so I’m struggling here. But I’m on the mailing list for The Oatmeal, which is either a webcomic or the nom de plume of the guy who writes and illustrates them, maybe both. If you’re not familiar with the site, you should be, because it’s far worse than this one in terms of being indelicate and irreverent, plus the illustration style defies description.
Recently, the extended comic ‘We need to talk about naked mole rats’ was posted, and seriously, check it out. It’s worth it just for The Oatmeal illustrations of an already unsavory-looking creature, but the information therein is actually fascinating, and certainly a lot more than I ever knew about the species, which is unique in quite a few ways. It would be easy to look at naked mole rats and think they have nowhere to go but up, evolutionarily-speaking, but the actual traits that they’ve developed are extraordinary. We shouldn’t be judging on appearances – we’re bigger than that.
Plus, it’s almost certain at some time that The Oatmeal thought, You know, drawing the tiddies of the queen mole rat is probably unnecessary, only to be immediately countered with, The hell it is!
I mentioned in the previous post about the possible explanation for the raised water levels in the pond, and The Girlfriend and I went out in the kayaks today to check things out. I would say the mystery is adequately solved.
That’s the edge of the kayak peeking in there, as it sat against the top of an impressive beaver dam, one that measured better than six meters in length across the drainage channel, and a meter or more difference in the water levels on either side. I could only get one decent perspective on it without trying to get out of the kayak and schlep around on shore someplace (which may come another day,) but I think these are expressive enough.
We only own half of the portion of the pond that we refer to as ‘The Bayou,’ and this sits beyond that dividing line, so technically it’s someone else’s property. It’s also not on the pond itself per se, but on an offshoot to the east, in the direction of the creek that forms the eastern border. It raised a few questions, especially given that we’ve been told the ponds are manmade, and the evidence for this was there – we also got down to the far end of the uniformly-shaped (more or less) pool and found the outlet pipe there. That was higher than this water level though. and this dam was beyond a break in the bank. It was responsible for flooding a very large section, seeming to extend all the way across to the creek itself.
So, what had caused the gap in the banks that allowed this to occur in the first place? Or, as I’m surmising right now, had the beavers dammed only a tributary of the creek, one seen beyond the dam in the photos, and the water level eventually surmounted a low point in the bank between this tributary and The Bayou, causing the ponds to become backed up too? That’s my working hypothesis right now.
From the shallow depth and the logs and cypress knees everywhere, I suspect the area seen in these two pics had been forest floor until recently, perhaps a bit boggy but otherwise solid – it now looks more like the creek flooded its banks, and we could potentially have paddled right on into the creek. Which would also explain the significant increase in trash in our ponds, since this became wide open water between the creek (receiving trash from the typical inbred redneck assholes that have to hurl their shit off the bridge where the road crosses the creek upstream) and the ponds. Which also means that my idea for putting a trash barrier along one channel would be next to worthless, because it wasn’t actually coming in that way.
The lodge was quite close by too.
While we have two beaver lodges on the property, one potentially abandoned, it would seem they weren’t the source of all the cutting and gnawing activity we’ve been seeing of late, since this is better than twice the size of either one, being a meter or more in outside height and showing fresh cuttings in its structure.
Which is another interesting point. Every lodge that I’ve ever seen in North Carolina has been dug into the steep banks of a stream, pond, or lake, rather than freestanding. The living area of the lodge itself is above water but underground, even when the entry is always submerged to prevent predator access, and the steep banks and land height above water level on the creek side permitted this; the minimal rise of the land on the pond sides wouldn’t allow for a dry chamber above water. This is the first tall dam I’ve seen where the living chamber might actually have been constructed under that log dome rather than dug out, perhaps even extended higher as the water level rose.
While we seemed to have two beavers living in one of those lodges near us, this confirms that there are certainly more within reach, and likely coming up to the backyard pond to snag more saplings as needed. Now, will I be able to get more pics or videos of these? That might be tricky, since there is no walking access to the dam or lodge that I know of, nor could see the potential of from the kayak, so that means I’d likely have to pack the photo equipment into a watertight case and haul it down to a nice vantage, beach, unload, and set up – and at least the return trip would be in full darkness. Not inconceivable, but a lot of effort, and not something I should be doing alone. Don’t count on it, is what I’m saying – unless someone wants to pony up some funding for the resulting pics and video? Let’s talk.
Perhaps having read my previous post where I dumped on February for being so dismal and rainy, it responded by producing a quite nice day today, as in, no jacket required, so take, take me home. The handful of leftover pics I had slotted to throw up here are now superseded by the ones I actually got today, and there’s just a few, so settle in.
We need to start with, the weeping willow (Salix babylonica) that I received last year is now kicking it for spring.
Unlike some of the other trees, the willow was very subtle about its early spring activity, producing only these very small buds tight against the branches like flattened thorns – until now, anyway. I don’t think the tree has quite topped four meters yet, but it’s close. And this is a wildly subjective thing anyway, since by nature it’s a floppy, droopy tree so the tallest branch may vary by half a meter or more depending on the wind and rain. I’ll try to get a size comparison soon, but right now, it’s slurping up all the rain in the boggy area we planted it within, specifically so it could – willows like wet ground.
Another tree was budding out enthusiastically too, but don’t ask me what.
I probably should know what this is, since it’s right on the edge of the pond and has been photographed before, but I really don’t know. Maaayyybe swamp maple? Regardless, it’s pretty brilliant against the clear sky.
I played around a little with what the sunlight produced, while nearby.
I noticed the yellow cow lilies (Nuphar lutea) were already springing back, visible under the surface but ready to overwhelm the pond again – that is, if the nutrias and the beavers let them, which is a big question right now, given how often those mammals are visiting. Of course, I had to back off a bit to get the bold reflections of the white trunks (another unidentified tree) in there. And then, the far more subtle part, the image is crossed horizontally with the shadows of other trees nearby, just making all sorts of interplay. That makes it fartistic, donchaknow.
The turtles had wasted no time taking advantage of the day, to be sure.
A small eastern painted turtle (Chrysemys picta picta) found one of the few dwindling basking spots in the higher water levels of the pond, while another painted and several yellow-bellied sliders (Trachemys scripta scripta) hog Turtle Island in the background. We really do need to make a few more basking spots, perhaps some kind of floating platforms (though maybe not – the winds may simply lodge those someplace shady and make them worthless.) I was shooting with the long lens to avoid spooking them, and snagged a closer frame of the little guy in the foreground.
Probably a little bigger than my hand-span in size, which makes it roughly half what the adults can achieve. I think the painteds are more wary than the sliders; the other day when The Girlfriend had the kayak out, she passed extremely close to a pair of sliders on Turtle Island who didn’t move until she was within three meters, which impressed me.
The turtles are definitely struggling with the higher water levels. I mean, they don’t care about the water per se, it just eradicates more of their basking areas.
Compare this image to this post (exactly a year ago!) when nineteen of them were all using that island. We really have to create something for them…
The Canada geese (Branta canadensis) were quite active today as well, congregating in pairs and, for the most part, just hanging out on holiday.
They’re still not up to the level of trust that they had last year, curiously, and maintain a moderate distance when we’re around, but otherwise aren’t concerned. It’s a nice quiet spot for them and pretty protected, so they seem satisfied with it. They gave me a few nice framing opportunities too.
The turtles look wary here, as if ready to bail if the geese got too close, but then a little later on, I captured this image:
The two turtles are still there to the left, if you look, and not at all concerned with being overrun. A little after this however, another pair of geese swam in from The Bayou and purposefully headed up here (the northern, opposite end of the backyard portion,) getting a little territorial with the ones seen here – nothing serious, but definitely herding them away a little. Those two then settled in on the other tussock with the broken snag (I think we’re calling it Goose Island now,) and so might have been the pair that looked like they were considering nesting there. Still monitoring this whole situation.
While we’ve seen some of the wood ducks close to the nest box, we’ve yet to witness anyone checking it out, but their nesting season is a little later on, I think. No, actually, we’re right on time (this post would go a hell of a lot faster if I didn’t keep searching for past posts that related.) But I took the opportunity to do a fartsy shot as one of the Canadas passed it by.
I’d raised that nest box this winter, not getting it as high as I’d intended, but I also hadn’t realized until looking at the posts from last year that the water level is up higher than I’d thought – it appears to be a solid 25cm or more. We think we now know why, too, but that’ll wait until I can get some pics to feature.
Okay, two more. First thing I was after, stepping out today, was to see how that lone sunspot was progressing, just to compare.
More visible now, with a companion, but not where I expected it to be – I need to check and see just how the sun’s axis is aligned in relation to Earth.
[This is slightly tricky. First off, the axis of both the sun and the moon, and Venus and Jupiter and all that, appear to realign as the day or night progresses, mostly because we’re seeing them from different angles as the Earth rotates – we just think “up” when looking at them in the sky, but that’s not the same as “towards celestial North” in any way. And then the viewing latitude makes a difference too, and our own planet has an axial tilt. So where the sun’s north pole sits in this image, I have no firm idea.]
And finally, a curious find that I want to check out better, but when I went out a couple of hours ago to try and find further examples, I came up empty-handed.
No more than a centimeter in length, these little unidentified snails were very visible just under the surface of The Puddle, catching the light quite well, but at full resolution here, some odd details are revealed. I initially though that what we’re seeing on the lower portions of the shells were mere reflections of the external parts of the snails as they – possibly mated? – but that doesn’t seem to align with what’s actually visible. So I suspect we’re seeing what’s inside the shells here, the anatomy of the snail that maintains contact when extruded, because the shells are that translucent. The two frames that I have are inconclusive, so I need to capture one or two to confirm this. Thus, there may be a followup to this, but not until next month (which is now just over an hour away.)
So that’s, what, twelve more images for February? That helps bring the numbers up for a relatively slow month in the winter, and I still have those leftover pics too. Plus, the busy season looms, so things should start picking up seriously very soon. And I need to jump on various spring projects too. Getting to be that time.
Or at least, we will be in less than 24 hours. Indeed, this one almost snuck up on me, since I wasn’t aware of how fast the month was passing. I had the beginning of March pegged for removing some of the plants from the greenhouse, and that’s tomorrow. Sheesh.
We also know what that means, so let’s see what we’ve accomplished on the abstract front, shall we?
I shot this one for a specific purpose, which has not yet come to pass, so we’ll leave the explanation until then – in fact, it will become clear then, so I won’t even have to explain it. So if the mystery is digging at you, well, you’ll just have to cope.
But then, we have two shot specifically for the end of the month, like, within the past hour, because we needed a better showing than that. This was all experimental photography, meaning I shot 132 frames trying for a decent effect, and will probably keep less than a dozen. Glad I wasn’t trying this on slide film.
I admit, I shamelessly played with the colors on this one, because the original color register wasn’t quite to my liking. I could’ve slammed the contrast way higher too, but let it go – there’s such a thing as too abstract.
No, there probably isn’t at that.
And one more:
Now, this one is not too hard to figure out, if you’re beyond a certain age anyway. But given how many overcast and rainy days we’ve had this month (part of the reason why it’s been pretty damn light on photos and posts here,) we needed some overwhelming color and contrast. Yes, these are all macro images – maybe I’ll change it up in March and see what the most distant thing I can photograph is. I’ve just barely snagged M33, the Triangulum galaxy, and at 2.724 million light years distance, it’s even farther than Andromeda. Can I beat that? I’ll have to do some research and see what’s in my field of view for March.
There still might be a few images sneaking in before the day is out, just to clear some of the folder, but nothing earth-shaking. March should definitely see an uptick though.
On Monday, we had clear enough skies for me to go out and check on the condition of the sun, or more specifically, the sunspots thereon. I could not actually make any out in the viewfinder, nor on the monitor when I had unloaded the card.
I considered myself a victim of bad timing, since we’ve been having so much activity in this form for the past couple of years, and the reason for that is, we’re around the solar maximum, or the peak of sunspot and coronal activity that occurs every twelve years. Ah, well, so it goes.
And then I came across an article that confirms that the sun is free from spots, for the first time in over 1,300 days; the last period where none were observed was just shy of four years ago in June 2022. This is a little more in line with the solar cycles, since the minimum of coronal activity should have been around 2020 (well, for the sun, anyway – it was a little different on Earth.) So while I was thinking I caught nothing, I actually snagged something mildly notable, purely by chance. Go me.
The article also says that yesterday, a new spot was spotted, uh, located, whatever, so this period seems to have been quite brief, and for sure, the peak never drops off that quickly, so more a matter of happenstance than likely any indication of anything odd happening up there. But as the overcast lightened into heavy haze this afternoon, I went out and tried again, though my exposure was set higher this time – normally, I aim to underexpose by about 2/3 stop to keep the solar disk from starting to bleach out, but with the haze, I left it at normal. As the haze thinned, this meant it was overexposing slightly.
I still wasn’t seeing any sunspots, and thought that perhaps the exposure was to blame, but then, there was a little smudge that showed in the same position through several frames, proving that it wasn’t a factor of the haze nor anything on my lens (since these were all handheld and thus the sun appears in a different location in the frame among all of them.) Let’s go to full-resolution for the detail:
Yep, there it is, just peeking over the top. Given that it’s not down towards the ‘side,’ it is likely to rotate a little more into view but still remain very close to the edge, since this is not terribly far from the sun’s pole. I’ll try to stay on top of it and see what happens.
Unfortunately, this meant that I blew the holiday off, since February 25th is Confirm Nothing Day. I confirmed nothing two days ago, but today, I confirmed something, which would be grounds for merciless teasing from my friends if they weren’t reluctant to admit that they witnessed this today. Though some might ask if I actually have any friends, which I will neither confirm nor deny.
Of course, if I simply delayed this post until Thursday instead, I meet the requirements of the holiday, at least in a left-handed manner, because while I confirmed that the new spot was indeed there on the 25th, I would not be publicly confirming that I had until the 26th. Though that’s kind of a half-ass solution…
I’ve been meaning to get to this for a while, and finally tackled it this past week. Herewith, a tutorial on using the ‘Curves’ function in many image editing programs to adjust brightness and contrast within an image, selectively as needed.
As noted therein, this won’t work very well if your monitor is poorly calibrated for brightness, contrast, and gamma, so it’s recommended to tackle this first if needed before making any adjustments to your images. You can find a guide with useful images at https://w4zt.com/screen/.
One of the benefits of Curves is that it maintains a gradual change, with neighboring or flanking values within the image receiving some effect too, so no single area becomes drastically (and noticeably) different from another, a sure sign of manipulation and, too often, creating an unrealistic and bizarre appearance. It can still occur though, so keep an eye on all areas within the photo when doing editing, to spot those little patches that can sneak in and look out of place.
I said it several times in the video and now I’ll put it in writing: be subtle. When editing, it’s very easy to keep pushing things a little farther, since we seem to become insensitive to how far is ‘too far,’ so I recommend setting aside the edited version for a little while, looking at something else, and coming back to it fresh to see if it still looks acceptable. These suddenly renewed ‘first impressions’ can count for a lot, because anyone else may have that same first impression.
Also, you can use the various selection tools within your editing program to pick portions of the image to tweak in Curves while leaving the rest alone, which could have been done with the trees at sunset example – just be sure to Feather the edges of the selection to fuzz out and make the border of the selected area indistinct, otherwise if will often show very clearly.
Part 2 is coming next week (I think,) and involves using Curves for color corrections, as well as some creative editing. Meanwhile, this post documents one of the most specific adjustments that I’ve performed, as an extreme example. Yet to me at least, it still looks more realistic, and less doctored, than some of the fartistic approaches I’ve tried. Which is still fine, but those latter examples cross the personally-drawn line between a photo and a digital creation – you may have your own line, or none at all, but I still feel that accomplishing it “in-camera” is where the real skill lies.
Later weekly posts in the Tip Jar topic will expand on some of the things covered here, so I wanted to establish a baseline of knowledge first, for those who haven’t used such functions before.
The other day (well, eight days ago) when The Girlfriend and I were out doing various property tasks, she came across three nearly identical finds that remain a small mystery, one I may be attempting to solve as I find the means to do so. To wit:
Right in one of the paths through the less-traveled sections of the property, she came up with this, the carapace of, most likely, a common musk turtle (Sternotherus odoratus.) While it was a warmer day, it had recently been quite cold, and so unlikely for the turtle to be out and about on its own for any reason, nor was it likely that this had been in the path since the time when it would have been out.
And another, smaller, but same species; we can tell by the faint ridge along the spine, and the small plastron:
Any of the other species in the area that might have a carapace similar to what we’ve seen would also have a plastron (belly shell) larger than this. Noticeable upon close inspection, however, was that these were fairly fresh, and by that I mean, had been in possession of their living owner until relatively recently, since remnants of flesh were still within, not fully dried out nor scavenged by ants.
In fact, a third that she’d found still had ants working on it, and so did not get photographed in my palm like these. Even I have my limits.
What’s curious to me is, what was digging up turtles hibernating for the winter, most likely in the mud at the edge of the pond, to eat them so recently? I was vaguely suspicious of the white ibis, since a few days earlier it had spent the entire day on the property, but this isn’t the kind of meal they tackle, nor is their beak made for this; they swallow prey whole for the most part, and certainly couldn’t section out a turtle. So I’m leaning towards raccoon, because we’ve seen them here and this might be something they’re adept at finding. Certainly not the nutrias or the beavers, which are both vegetarian. Also odd that the turtles seem to have been eaten in roughly the same time frame, all left out in the open in plain sight.
Most such activity, of course, would take place at night, and while I’ve been out quite often at night and caught glimpses of various critters, the opportunity to actively observe them hasn’t been there, given that a) they’re usually aware of me before I’m aware of them (though not always,) and b) I don’t have that night vision thing going on. There are options and I’m working on a couple, but the property is also quite large and so covering any decent portion of it is tricky. We actually did have a camera trained on the backyard and pond edge, which may be back in operation within a week or two, but it was so distant from the pond (wide-angle lens, of course,) that its motion sensor probably wouldn’t be triggered by anything smaller than a deer. Still working on it all.
The same day as the turtle shell finds, the late afternoon light was great and the wood ducks were congregating at the pond edge, so I slipped upstairs and managed to open the window without spooking them, and thus got a few nice portraits while their feathers were shining in the bright sunlight. Usually they avoid such conditions but, you know, corn…
These were at 600mm focal length but quite far removed from the ducks, so this is tightly cropped but not bad for that. The color palette is what I was after, and this shows the iridescence of the head feathers, the muted blue iridescence of the wings folded across the back, and a faint hint of the very fine stippling that adorns their sides (seen in better detail here.)
And then a couple of direct portraits.
I like this one for the reflection, which is almost ideal, a chance timing thing when the rippling of the water was just right. I could do without the intervening branches (I say that a lot, don’t I?) and it would be nice if the water reflected greenery instead of the winter browns, but hey, I’ll still take it. and the next is better, I think.
Better light and head angle, even if we don’t have as much of the colors. It’s funny: we’ve unintentionally conditioned the nutrias, and to a smaller extent the beavers, simply by putting down corn for food, but the wood ducks haven’t even begun to habituate since they always flee at the first sign of us in the backyard – they don’t even realize it’s us that distributes the corn since they’re well out of sight before this happens. So my attempts to get closer portraits (and a wider variety) is not progressing much at all. The ducks, in fact, inhibit a lot of work I might do in the backyard since I hate to spook them. Then again, I remember what I was considering a little over a year ago, and it didn’t realistically include the ducks being right freaking here, so I can cope, even while I keep trying.
Just two this time, even though the last sorting session was pretty hefty – I just featured most of what I liked at the time that I took them (well, in a reasonable time frame thereafter, anyway.) So we only have these:
One of several images taken of a roseate spoonbill (Platalea ajaja) while at Sylvan Heights Bird Park, I liked this perspective just for how it highlights the beak, and the fact that the bird could easily open paint cans if it so desired.
And this one, same place:
With this, I discover that I’ve never featured a scarlet ibis (Eudocimus ruber) before, even though I have images of them dating way back, like mid-nineties or thereabouts. I could have done without the background, but while three of them were preening identically while all perched in the top branches of a tree, I had to snap the image – the one at top is in juvenile coloration. Part of the reason I have not featured these before is that they’re not native to the US; though they might make the occasional appearance in south Florida, they’re native to the Caribbean and South America, so all of my pics have been captives in one place or another.
And I realized a short time back that, while I announced a potential solution to autofocus woes during video in two separate blog posts, I think, I never followed through. I’d switched to using the camcorder for the night work with the nutrias and beavers, refining that option until it was working quite well, but I also improved the use of the long lens for the daytime work with the ducks et al, and that was by obtaining a Canon 70D body instead, one that does allow autofocus while shooting video. That’s what these, and all of the video from the bird park, were shot with, and it works quite well.
Credit where it’s due, since this was a christmas present from The Girlfriend, even though I was the one that not only picked it out (at her insistence,) but sealed the winning bid – she gets too anxious with sniping on eBay. It arrived a couple weeks before christmas, and I got a short while to test it out and ensure that it was in working order, then it got packed away until the 25th because early presents are verboten. But in that time, I bought myself the battery grip, batteries, and large memory card.
A note about Canon’s naming/numbering conventions: Normally they’re a little backwards, in that the high-end bodies are single digits (like the 7D) while the more basic, lighter-option models are often in the hundreds. I was shooting with a 7D (still am, really) and then received this 70D which is clearly an upgraded, high-end model, and after getting used to this naming convention I keep getting mildly confused when unloading either body. It does not help that the memory cards themselves are named identically (“EOS DIGITAL,”) so I have to remind myself of what I’m doing constantly.
But yes, actually having autofocus while shooting video is a major boon, though why this wasn’t included in the earlier bodies I don’t know, since the HFS-100 camcorder that I’m using is way older and manages it just fine. Probably something to do with being a DSLR. Regardless, I’m able to shoot video without constantly keeping my hand on the focus ring, which likely contributed at least a little to the large number of video clips that I also had to sort through this time. The real culprit, however, was having so many subjects easily at hand. Gonna need to upgrade harddrives in the workhorse computer soon…
Fairly basic one this week, since I have several that I’d like to tackle that will take more preparation than I have time available for right now. So we’ll talk about one of the staples, and that’s ISO, formerly (unofficially) known as film speed.
Short explanation: ISO refers to how sensitive the digital sensor (or indeed, the film) is to light; the higher the number, the more sensitive it is and the less light is needed to achieve a “proper” exposure, and that’s in scare-quotes because there is no such thing. There is an average, though, and that’s what camera exposure meters and light meters are calibrated to produce, but since not every scene or subject is average, they can’t always produce the ideal exposure, and it’s up to the photographer to accommodate these shortcomings.
Long and technical explanation: ISO actually stands for International Organization for Standardization – yes, that’s correct, I initially thought it was that way for the French version, but that’s not abbreviated ‘ISO’ either. It’s a system of rules to have all the different countries and cultures using the same measurements for everything, and you might already have experience with ISO 9001 with corporate culture, or other numbers if you’re into engineering. For photography, technically it’s ISO 6, or even 6:1993, and is a direct translation from ASA; ASA 100 films and ISO 100 settings on digital cameras have the same light sensitivity. You will likely never have a need for this info in your life, but at least this answered that idle question.
ISO progresses much the same way as shutter speed, so ISO 200 is twice as sensitive (requiring half as much light) as ISO 100. From there, 400, 800, 1600, 3200, and so on; these are typically called, “stops” or “EVs: for “Exposure Values.” Most cameras can be set for values in between these, such as 320, and these are subtle differences, partial stops or partial EVS, but even so, the math holds up: ISO 640 is twice as sensitive to light as ISO 320. We just deal with the whole hundreds because it’s easier overall, and ISO 100 is considered the base setting.
Generally, the way it works is, if your meter indicates that the correct exposure is f5.6, 1/50 second shutter speed at ISO 100, but you want a faster shutter speed to prevent blur, you could change the ISO to 200 instead and now use a shutter speed that was twice as fast at 1/100 second. Or keep going – ISO 400 and 1/200 second, ISO 800 and 1/400 second, and so on. Simple!
Only, like everything in photography, there’s a tradeoff, and the tradeoff in increased ISO is decreased quality and resolution. The simple guideline is, use the lowest ISO you can to get the shot – but get the shot.
2x resolution example of high ISO image degradation in a night sky exposure, the blotchiness in the dark areas, as well as the noise of bright red and blue pixels – the brighter grey and white pixels are stars and actually belong there.The funny thing is, for both film and digital, the effect of increasing ISO is almost the same, even though they use entirely different ways of capturing light. Mostly, it’s increasing blotchiness and ‘snow’ in the shadowy areas where there’s little light, but digital sensors also suffer from ‘noise,’ which is singular pixels of bright colors, very often in the exact same place in every photo.
Brief, and probably none too accurate, explanation: digital sensors work by converting light energy into electrical. When you boost the ISO higher, you’re attempting to read tiny voltages from the sensor and amplify them. But the sensor doesn’t just pick up voltage from light, but also from other sources of electricity (including the other parts of the camera itself, and static charges from the air,) as well as minor manufacturing defects that cause the sensor to be less than uniform. In scattered cases, individual pixels in the sensor produce a “full brightness” response to no input at all, producing red, blue, or green dots in an otherwise dark field. While in film, the chemicals that crystallized under light also had variability, causing small splotches of brighter regions usually referred to as “grain.” Just not the bright specks of “noise” that digital sensors produce.
This is mostly visible in shadowed or dark areas of the exposure, but could also show up visibly across the gentle gradient areas if the ISO is really high. And this blotchiness can also reduce the sharpness of the image, faintly blurring the edges that should be sharp.
Also, longer exposures give the sensor more time to register stray electrical charges, and so the noise will often be worse.
In short, avoid using higher ISOs as much as you’re able. But there are certainly times when you need that edge.
Note: complicated, detailed subjects will often hide the effects of high ISO, and you can get away with it more while shooting such subject matter. Conversely, large areas of the same tone or very subtle gradient changes will show the effects much worse. This is especially true when doing night sky exposures.
So, how high is too high? There’s no easy answer to that. Part of it depends on the camera itself, since manufacturers are constantly trying to improve the ISO response in their camera bodies (mostly in the image processing portion, since the sensors themselves undergo few changes.) And part of it depends on your subject matter, as indicated above. Part of it depends on how large you will be displaying the resulting image, or how far you will enlarge portions of it – if you’re reducing the entire frame down to web resolution, you may notice nothing at all. And part of it depends, quite simply, on how picky you might be.
ISO 800 with the old Canon 30D, alongside a 2x resolution sample of the sky at upper right. Acceptable at web resolution perhaps, but probably not as an enlarged printIn cases like the one above, the high ISO effects showed in the sky more than a little, but blended into the sand and driftwood. If you desired to make a larger print of an image like this, some editing might be in order, otherwise that ‘grain’ in the sky could be too noticeable.
There are some things you can do to cope. First off, you can occasionally avoid using a higher ISO altogether by using a tripod instead, or even just going with a wider aperture to let in more light that way. But if it’s a choice between blurring the image from camera shake during a handheld shot, or dealing with ISO grain, go for the gran every time – you can even use it to artistic advantage in a few cases. Some cameras have a Long Exposure Noise Reduction option that may be worth a try; I’ve only used this a couple of times with night shots, but the processing time took as long as the exposure did and thus prevented me from getting shots in the interim, not ideal when you’re hoping to catch meteors, but perhaps still worth a few experiments.
In the shot above where the grain shows most noticeably in the sky, you can often smooth out this blotchiness in an editing program: select by color range and pick the worst areas of the sky, and feather the edges of this selection by several pixels (perhaps as high as 20 pixels if doing this at full resolution,) then Blur your selection by 1.5 to 10 pixels or so – season to taste. You might have to do this for a couple of sections, just be careful about overlapping into the detail areas such as (in this case) the driftwood or the horizon line.
Sensor noise, especially during night exposures, can be eradicated almost entirely with editing – I have a page on this already. Just be sure to obtain a recent baseline noise register, because sensors will degrade slightly over time and more noise will creep in, so re-using an old noise baseline might miss the new noise pixels.
I recommend doing a few experiments with your camera with different scenes, but most especially something with distinct dark or shadowed areas, and keep boosting the ISO up to the maximum the camera will allow, then check out the results carefully on a larger screen (not the camera LCD, for dog’s sake!) In my experience, the highest usable setting for decent results is two stops below what the camera can achieve, so if your camera’s maximum is ISO 6400, you may want to avoid anything higher than 1600, but use your own judgment. Again, the amount of gradient or dark areas and the end usage may dictate your limits better than an overall rule.
And on occasion, you can take a horribly grainy image and do something creative with it. Simply converting to monochrome may make it acceptable, solely because we expect B&W images to be grainy sometimes, from experience with very old photos. A little later on, I’ll have a tutorial on selectively smoothing portions of an image in an editing program, a slick little trick.
Hopefully this was helpful in at least some way, but more advanced stuff will be along. Good luck!
I’m supposed to be working on the weekly post right now, but I heard a noise outside and, since it was nearly 11 PM, I thought I’d check – you only get one chance to be eaten by a bear, you know? Though despite my cavalier attitude in the preceding sentence, I was cautious and went out slowly, checking the area with the headlamp carefully, finding nothing at all that might have made the noise. Doesn’t mean much – could have been a falling branch or something of that sort. But on returning, right alongside the door into Walkabout Studios I found a small frog, surprising me a little even though it shouldn’t have. I managed to capture it and bring it in for a studio session, for which it was not at all amenable.
This is a spring peeper (Pseudacris crucifer,) and while it’s February, it’s also supposedly 10°c out there and raining gently, though it feels a couple of degrees warmer to me. Peepers definitely get an early start in the spring, or in anything that seems like it, so this wasn’t as odd a find as I initially thought upon seeing it. This is one of only two frames taken in the shallow dish that I use as a ‘setting’ for studio work with little critters, and I only managed two because this little guy wasn’t having it, and would pause for no more than ten seconds, usually less, before leaping away. Which is why I was doing this in the bathroom, since this provided a lot fewer places to hide. The first frame that I obtained was this:
Yeah, that’s a small scrubbing brush on my sink – the peeper continually leapt away towards the wall over the sink, and so I surmised that it was aiming for altitude, trying to climb higher, and switched over to another setting.
This is almost an acceptable natural setting, if I crop out the teal planter edge peeking in, and if you’re ignorant of the plant species, which is a neverdie (Kalanchoe crenata) and native to Madagascar, which these frogs are not. It was what I had available indoors that might serve to disguise the background, but the frog wasn’t any happier on this and kept leaping to new positions, so I gave up after a few minutes and went to return it outside. There, I thought I’d make one last attempt, and carefully coaxed it onto the coral bark Japanese maple, thinking it might be okay for a short while in the tree. Set the transport container down, switched on the camera and the flash, turned back and… gone already. Nowhere in the tree, and the ground around it was ideal camouflage for something the size of a smaller coin, so I figured I was done with this subject.
On a whim however, I decided to check out some of the other trees, because the conditions were kind of encouraging to peepers, and this did indeed pay off.
This is a neighboring tree, actually the dead one that nonetheless served as a favored roost for one of the Carolina anoles throughout the summer and fall. Just a little too far to be the same frog seeking shelter from the annoying paparazzi, and actually the second of three that I found with only casual searching; I even heard a couple of sporadic calls.
I figured I’d take a few minutes because it really wasn’t bad out and there wasn’t anything that I should have been doing instead, and found something dangling from another tree, firing off a few frames of this new subject.
Seeing the pale grey color with the legs dangling and watching it twist in the tiny breeze, I figured this was probably only a molted exoskeleton, but after a few moments it reanimated and scrambled back up the web strand it was dangling from.
Some form of tiny crab spider (Thomisidae,) though I wasn’t shooting with the macro lens nor inclined to do a full study, so this is all we have. Spiders are surprisingly cold-hardy as well, often reappearing at temperatures even lower than this. Had I not already released (lost) the peeper, I would have collected this spider to provide a meal to the frog, just to show there were no hard feelings. Well, towards the peeper – the spider would have been shit out of luck.
Finally coming back inside, I stopped right near where I’d first found the frog and checked the Magic Bucket, the trash can right outside my door for all the smellier, fume-ridden things I produce with my various pursuits – it only had a couple of paper towels and a small dead beetle in it, but as I shook it gently, this little guy popped out.
Yep, another Carolina anole, which means that even in winter I should be checking this damn thing regularly. No idea how long it might have been in there, so I carried it over to the greenhouse (where several of its brethren are already spending the winter) and dropped it off inside – there would at least be a certain level of warmth maintained by a small heater, as well as plenty of water and whatever little insects happened to be available, especially since on the warmer days we open the vents, and the citrus trees are still blooming and attracting pollinators.
This isn’t one that lends itself to an easy description, or a slick way of introducing it, so I’m struggling here. But I’m on the mailing list for The Oatmeal, which is either a webcomic or the nom de plume of the guy who writes and illustrates them, maybe both. If you’re not familiar with the site, you should be, because it’s far worse than this one in terms of being indelicate and irreverent, plus the illustration style defies description.
