1D MkIII - "ISO Priority", a feature I've wished for!!!

Edit: Actually, maybe "Auto ISO" is a better name than "ISO Priority".

A while back, before ordering my recently received Canon 1D MkIII... I was wishing for a feature. In my mind, I called it "ISO Priority". The concept being that given a chosen aperture, I wanted the camera to auto-select ISO to give me a "suitable" shutter-speed.

What is a suitable shutter speed? It's one where I am confident that i could handhold the shot... so for me, right now it's around 1/60th... maybe 1/30th with one of my IS lenses assuming a non-moving subject.

When I first played with the MkIII, I saw the "ISO Safety Shift" C.Fn I-8. This didn't really do what I wanted because it would only shift the ISO after it decided it couldn't get proper exposure at 30 seconds... kind of worthless. But driving home today from work, I remembered that there was a setting in the custom functions that at the time, I didn't understand why anyone would need to set it differently from default. That setting is C.FN I-12 or Set Shutter Speed Range.

I set the lowest speed shutter to 1/60th... meaning the camera will now not attempt to shoot at anything with a shutter speed of 1/60th or slower.

So now, with C.Fn I-8 and C.Fn I-12 set, I've created "ISO Priority". When shooting handheld in varying light conditions like an indoor/outdoor house party or somewhere with a lot of sun and a lot of shade... all I need to do is set the camera to aperture priority mode (because I like to control DOF) and I can rest assured (especially with the MkIIIs exceptional handling of noise) that I will get the "best possible shot" within the bounds of my set aperture, a maximum shutter speed of 1/60 and the lowest ISO possible to properly expose the shot because while I have the camera set to ISO 100, it will push anywhere from 100 to 3200 as needed for proper exposure.

For example, at a birthday party, I'm shooting out by the pool using my 70-200 f/2.8L IS and it's very sunny. I put the camera Aperture Priority set to f/5.6, ISO 100 and it selects 1/1000. I then head into the house and it's darker, using the same settings, I'm able to shoot a picture inside, handheld at 1/60th shutter speed, but "ISO Priority" has bumped me to ISO 800 automatically. Without the combination of C.Fn I-12 with C.Fn I-8, the camera would have wanted an unacceptable shutter speed for handholding. And if I was to use "P" mode without these custom functions set, it would have changed the aperture to wide open and then progressed to slow down the shutter to beyond my handholding capabilities unless I manually bumped the ISO myself.

And while I don't shoot in Shutter Priority very often (maybe at a motorsport track event in order to get decent motion blur), I could do the same thing by selecting the shutter speed I want, using C.Fn I-13 to limit the range of available apertures (probably 5.6 to 11 for motorsports) and then once again using C.Fn I-8 for "ISO Priority" to ensure that I get the lowest noise possible within the range of parameters specified.

I'm a n00b to the world of the 1D camera, so maybe other cameras have these C.Fn features, but to me, this is just awesome and my new camera has this "semi-auto" feature that allows me to select aperture via Av, but automatically selects ISO between ISO 100 - 3200 to get me the shot I want knowing I can't handhold anything slower than 1/60th.

So far, that and many other features, are unique to the MkIII.

Something Nikon's had right for a while

I have to wonder the point, considering all ISOs are clean or at the very least usable now. Doesn't sound like something I'd prioritize...ever.

EDIT: Ok nevermind. Auto ISO I can get behind.

wow...that's a pretty cool idea. For me, the only advantage of the iso shift thing was that if I went from indoors with high iso into the bright daylight and forgot to put my iso back down, the camera would decrease the iso value so that I could take a usable picture. Your idea is kind of fun, however I usually watch my shutter speed anyways...but now I can depend on laziness/custom functions.

could be a good use of one of the custom function sets.

Now this is something I would DEFINITELY make a LOT of use of. Incentive to upgrade at the end of the year...

this catches my attention also.. Thank you for posting this euge.lee!

Getting a Mk III will not be done before January, but you just tweaked me a bit more.

You've got my mind working overtime this early in the morning. I thought I had this same effect the other day and didn't use both settings. But, I was shooting shutter priority at the time.... I had ISO Safety Shift enabled, but didn't do the other thing you mentioned. I set the ISO to 1600 and Shutter Priority to 1/500. It started at f/2, but then shifted first to f/1.8, and then started bumping the ISO up as needed. But I was OK with wide open. I think I get it now... if I had wanted to restrice the aperture to f/2, I could have gone into the comparable CF for setting aperture restrictions and maybe had it move aperture down from say f/2.8 to a max of f/2, before it started shifting ISO. I think I get it, and definitely see the need for it more going the other way with shutter vs. aperture. And, I do shoot aperture priority a lot.

What happens if it can't get to a suitable exposure even at ISO3200? Will it still take the shot and underexpose it to keep the shutter 1/60s?

convergent wrote in post #3618233
What happens if it can't get to a suitable exposure even at ISO3200? Will it still take the shot and underexpose it to keep the shutter 1/60s?

Yes, it still shoots. I did this at the zoo yesterday. It shifted to 3200 frequently. It flashes at you when it can't get the correct exposure, but it still fires. I was using fill-flash, so I still got usable shots.

Like the first shot: He was inside a hallow stump, with already dim light, shot through plexiglass. ISO-3200

Or, the second shot: Hidden in the brush. 400mm ISO3200, no-flash, pushed by 1/3 stop in lightroom to make up for the undexposure.

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this one is among the reasons I'm thinking about the mark III. please tell me, how does it work with flash, in AV mode? will it automatically bump the ISO to "correctly" expose the background (current ETTL automatically drops the shutter speed to correctly expose the background)? also, in M mode, does this setting prevent you from dialing in a slower shutter speed?

thanks in advance for the info...

In Av, the camera should expose for ambient, irrespective of the flash being on or off. Only in P mode with a Canon EOS camera adjust for the presence of the flash being on. I haven't tested this in the Mark III, but I'd be surprised if this were different from other bodies... although the Mark III is capable of completely controlling the 580-EXII... still don't think they would change this, its kind of a fundamental flash deal.

If you set the limit in the Mark III to a particular shutter speed range, then it takes lower shutter speeds off the camera. Almost all the setting can be limited. For example, you can set it up to not even have some modes... like if you only wanted Tv and M, you could remove the other modes from the menu. They would be just gone. Same thing for ISO, shutter speed, aperture, etc. If you limit them, its like they don't exist in the camera any more. This is how you can force a particular mode if you want to control things by preloaded settings. If you elminate all the choices except one, then loading those settings will setup the camera a particular way, and you wouldn't be able to change it.

Well, I stand corrected... I just did a little test and it works differently than I thought.

I setup the camera to limit the shutter speed to 1/30 on the low side and turned on ISO safety shift. I set it to Av and f/5, ISO400.

Test 1 - dark corner of my office
- Flash Off - shifted to ISO3200
- Flash On - shifted to ISO3200

Test 2 - book case in my office
- Flash Off - shifted to ISO3200
- Flash On - shifted to ISO2000

I repeated this around the office and got similar results. In lighter situations it doesn't seem to shift the ISO as far if the flash is on... I guess knowing the flash will help the situation. In very dark situations it knows it still needs all the ISO. This seems to be a pretty intelligent way to operate and I'm surprised. This will be VERY useful.

That is useful, had not twigged that one.
Just applied it and tried it in "AV" mode

I will be using this a lot

Thanks

I've been using ISO shift in Tv mode, all the time, and even limited the Av to get the DOF I'm looking for.

But, I haven't used it in Av mode. I'm usually shooting with longer lenses, and 1/60th isn't fast enough for my hands. I just have to remember the option is there when I'm shooting shorter lenses.

JohnC

Cathpah wrote in post #3618006
wow...that's a pretty cool idea. For me, the only advantage of the iso shift thing was that if I went from indoors with high iso into the bright daylight and forgot to put my iso back down, the camera would decrease the iso value so that I could take a usable picture. Your idea is kind of fun, however I usually watch my shutter speed anyways...but now I can depend on laziness/custom functions.

could be a good use of one of the custom function sets.

Yeah, definitely a good tool when in more of a "lazy" or "quick reaction" type shooting mode. I think this feature set is a perfect compliment for C.Fn I-14 too that could allow you to have the "most likely or ideal" settings programmed for the * button.

convergent wrote in post #3618233
You've got my mind working overtime this early in the morning. I thought I had this same effect the other day and didn't use both settings. But, I was shooting shutter priority at the time.... I had ISO Safety Shift enabled, but didn't do the other thing you mentioned. I set the ISO to 1600 and Shutter Priority to 1/500. It started at f/2, but then shifted first to f/1.8, and then started bumping the ISO up as needed. But I was OK with wide open. I think I get it now... if I had wanted to restrice the aperture to f/2, I could have gone into the comparable CF for setting aperture restrictions and maybe had it move aperture down from say f/2.8 to a max of f/2, before it started shifting ISO. I think I get it, and definitely see the need for it more going the other way with shutter vs. aperture. And, I do shoot aperture priority a lot.

What happens if it can't get to a suitable exposure even at ISO3200? Will it still take the shot and underexpose it to keep the shutter 1/60s?

Yeah, wasn't a big deal for you when you were at f/2 and then it pushed to f/1.8 before bringing in "ISO SHIFT", but imagine that you wanted/demanded f/8, without limiting the shutter, you'd of significantly decreased your DOF before the camera safety shifted the ISO.

If it can't even expose at ISO 3200, it will underexpose the picture, and the camera will show you the "EC" it will be using.

PeterUK300 wrote in post #3618858
That is useful, had not twigged that one.
Just applied it and tried it in "AV" mode

I will be using this a lot

Thanks

I was excited when I saw ISO SAFETY SHIFT, depressed when it moved me to a 30 second exposure before shifting... and now I'm excited again!