I'm sure that image nerds would poke holes in it, but it seems to work pretty much exactly the way it does IRL.
The noise at high ISO is where it can get specific. Some manufacturers make cameras that actually do really well, at high ISO, and high shutter speed. This seems to reproduce a consumer DSLR.
Not sure why value on the exposure compensation scale changes in manual mode when ISO is fixed. Shouldn't it be static in that case, unless ISO was in auto?
For me it's missing something to illustrate the relationship between shutter speed and motion blur. If the subject was a running fan instead of of lightbulb that would have been ideal.
I know that modern systems like aperture priority or full auto make things easier, but I maintain that the many photos I took with a fully manual film camera (Canon AE-1) were simply better than those taken with any subsequent DSLR. The simple act of calibrating the shutter speed, aperture size, and manual focus before and during shooting helps you slow down and think about composition and framing, making the end result more valuable. Same goes for the limited number of shots on a roll of film.
Nowadays it’s easier to just take lots of shots and fiddle with the setting and do bracketing and such. But I maintain something important was lost by the move to automatic cameras.
Even today you are better off shooting manually once you have metered the scene.
Otherwise your meter will pick up on color differences in a given framing and meter slightly differently. Shots will be 1/30th of a second, 1/25th of a second, then thanks to the freedom of aperture priority you might get little weird 1/32ths of a second you don't have discretely on a dial. How about iso. same thing, one shot iso 200, another iso 250, 275 this other one. Oh this one went up to iso 800 and the meter cut the shutter speed. Aperture too. This one f2 this one f4 this other one f2.5. This wasn't such a big deal even in the full auto film era since 35mm film has such latitude where you can't really tell a couple stops over or underexposed.
All these shots, ever so slightly different from one another even if the lighting of the scene didn't really change.
Why does this matter? Batch processing. If I shot them all at same iso, same shutter speed, same aperture, and I know the lighting didn't really change over that series of shots, I can just edit one image if needed and carry the settings over to batch process the entire set of shots.
If they were all slightly different that strategy would not work so well. Shots would have to be edited individually or "gasp" full auto button which might deviate from what I had in mind. Plus there are qualitative trade offs too when one balances exposure via shutter speed, vs via aperture, vs via iso.
I agree with slowing down and taking my time if I am shooting something static, but if I am outdoors taking pictures of anything that moves (e.g. birds), I am going to shoot in full auto burst mode until the buffer/SD card is full.
I understand I am relying more on luck and not being as deliberate with composition when I do that, and I have high respect for people who are able to get great wildlife photos with film. But for amateurs like me, it's far easier to get better pictures simply by taking more pictures.
One thing that is lost when using auto cameras is using focus & DOF as part of composition. With an auto-everything camera, the only part the user does is frame the shot. But composing requires thought about where you choose to place the focal plane, and the depth of field. Also lost with auto digital is pre-visualisation. No need for it as most people just bang off shots & look at the result. The delay of seeing film developed means film prohotographers learn to previz their shots. Less and better.
This is honestly the best and most simple way to learn photography, at least something basic that is still very hard to grasp sometimes. I know photography is not just about the photometer, and about depth of field, but this simple simulator helps to learn about these relationships between aperture size, shutter speed and ISO which always bugged me (sometimes my shots were bad and sometimes great).
> image "noise" or "grain" that is introduced into a picture as you increase the ISO
Not this absolute shit again. This is not how photography works or how physics actually work. Image noise does NOT come from high ISO, it comes from low exposure (not enough light hitting the sensor). ISO is just a multiplier between a number of photons and the brigthness of a pixel in your photo. The implementation of the multiplier is (usually) half-analog and half-digital, but it's still just a multiplier. If you keep the exposure the same, then changing the ISO on a digital camera will NOT introduce any more noise (except for at the extremes of the range, where, for example, analog readout noise may play a role).
This "simulator" artificially adds noise based on the ISO value, as you can easily discover: Set your shutter to 1/500 and your aperture to F8, then switch between ISO 50 and ISO 1600 and look at the letters on the bulb. ISO 50, dark but perfectly readable. ISO 1600, garbled mess. Since the amount of light hitting the simulated sensor stays the same, you should be seeing slightly LESS noise at ISO 1600 (better signal to noise ratio than at low ISO), not more.
edit: To add something genuinely useful: Use whatever mode suits you (manual, Av, Tv) and just use Auto ISO. Expose for the artistic intent and get as much light in as possible (i.e. use a slower shutter speed unless you need to go faster, use a wider aperture unless you need a narrower one). That’s the light that you have, period. Let the camera choose a multiplier (ISO) that will result in a sane brightness range in your JPEG or RAW (you’ll tweak that anyway in post). If the photo ends up too noisy, sorry but there was not enough light.
ISO is an almost useless concept carried over from film cameras where you had to choose, buy and load your brightness multiplier into the camera. Digital cameras can do that on the fly and there’s usually no reason not to let them. (If you can come up with a reason, you probably don’t need this explanation)
> Image noise does NOT come from high ISO, it comes from low exposure [...] changing the ISO on a digital camera will NOT introduce any more noise (except for at the extremes of the range, where, for example, analog readout noise may play a role).
Sounds like you're saying that setting higher ISO does cause noise, but as long as you don't go too high you won't really notice the difference?
Agreed. In other words, ISO is not exposure. Exposure is purely about how much light arrives on the sensor - which is a combination of scene illumination, object reflectivity, relative aperture, and shutter speed. ISO only plays a part in controlling how bright the output image is.
kinda lame to use "brightness" as an analog for exposure, they're really not the same thing, at the very least do the transformation in a deeper color space before displaying it to the screen, the source images almost certainly have more than the 8 bits being used here
Every photographer knows very well the exposure triangle: shutter speed, aperture and ISO, but in astronomy usually only aperture and focal ratio are considered.
So I added a third dimension to illustrate the basic triad of astrophotography: telescope aperture, focal ratio and image resolution.
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[ 2.5 ms ] story [ 48.5 ms ] threadI'm sure that image nerds would poke holes in it, but it seems to work pretty much exactly the way it does IRL.
The noise at high ISO is where it can get specific. Some manufacturers make cameras that actually do really well, at high ISO, and high shutter speed. This seems to reproduce a consumer DSLR.
It all matters.
Nowadays it’s easier to just take lots of shots and fiddle with the setting and do bracketing and such. But I maintain something important was lost by the move to automatic cameras.
Otherwise your meter will pick up on color differences in a given framing and meter slightly differently. Shots will be 1/30th of a second, 1/25th of a second, then thanks to the freedom of aperture priority you might get little weird 1/32ths of a second you don't have discretely on a dial. How about iso. same thing, one shot iso 200, another iso 250, 275 this other one. Oh this one went up to iso 800 and the meter cut the shutter speed. Aperture too. This one f2 this one f4 this other one f2.5. This wasn't such a big deal even in the full auto film era since 35mm film has such latitude where you can't really tell a couple stops over or underexposed.
All these shots, ever so slightly different from one another even if the lighting of the scene didn't really change.
Why does this matter? Batch processing. If I shot them all at same iso, same shutter speed, same aperture, and I know the lighting didn't really change over that series of shots, I can just edit one image if needed and carry the settings over to batch process the entire set of shots.
If they were all slightly different that strategy would not work so well. Shots would have to be edited individually or "gasp" full auto button which might deviate from what I had in mind. Plus there are qualitative trade offs too when one balances exposure via shutter speed, vs via aperture, vs via iso.
I understand I am relying more on luck and not being as deliberate with composition when I do that, and I have high respect for people who are able to get great wildlife photos with film. But for amateurs like me, it's far easier to get better pictures simply by taking more pictures.
That friction of adjusting machinary to capture what we felt against what we saw was part of the process.
It slowed us down just long enough to appreciate the patterns, the textures, the form, the haesscity of a moment that seized our attention.
Not this absolute shit again. This is not how photography works or how physics actually work. Image noise does NOT come from high ISO, it comes from low exposure (not enough light hitting the sensor). ISO is just a multiplier between a number of photons and the brigthness of a pixel in your photo. The implementation of the multiplier is (usually) half-analog and half-digital, but it's still just a multiplier. If you keep the exposure the same, then changing the ISO on a digital camera will NOT introduce any more noise (except for at the extremes of the range, where, for example, analog readout noise may play a role).
This "simulator" artificially adds noise based on the ISO value, as you can easily discover: Set your shutter to 1/500 and your aperture to F8, then switch between ISO 50 and ISO 1600 and look at the letters on the bulb. ISO 50, dark but perfectly readable. ISO 1600, garbled mess. Since the amount of light hitting the simulated sensor stays the same, you should be seeing slightly LESS noise at ISO 1600 (better signal to noise ratio than at low ISO), not more.
edit: To add something genuinely useful: Use whatever mode suits you (manual, Av, Tv) and just use Auto ISO. Expose for the artistic intent and get as much light in as possible (i.e. use a slower shutter speed unless you need to go faster, use a wider aperture unless you need a narrower one). That’s the light that you have, period. Let the camera choose a multiplier (ISO) that will result in a sane brightness range in your JPEG or RAW (you’ll tweak that anyway in post). If the photo ends up too noisy, sorry but there was not enough light.
ISO is an almost useless concept carried over from film cameras where you had to choose, buy and load your brightness multiplier into the camera. Digital cameras can do that on the fly and there’s usually no reason not to let them. (If you can come up with a reason, you probably don’t need this explanation)
So does this mean that changin the ISO directly on my camera, or in DarkTable/whatever at post-proc time is virtually the same?
Sounds like you're saying that setting higher ISO does cause noise, but as long as you don't go too high you won't really notice the difference?
Don't tell me what to do!
Every photographer knows very well the exposure triangle: shutter speed, aperture and ISO, but in astronomy usually only aperture and focal ratio are considered. So I added a third dimension to illustrate the basic triad of astrophotography: telescope aperture, focal ratio and image resolution.