gvarner Loc: Central Oregon Coast

I have a D7000 and like to use P mode most often. I can then change the shutter speed and or the aperture and or the ISO and the others will follow (well, kinda sorta). I programmed the D1 for P mode and Auto-ISO to shoot in museums and indoors without flash. In low light, grain is always an issue in big prints but that's where noise reduction PP comes in. Sometimes noise adds to the ambiance of the shot, the mood.

amfoto1 Loc: San Jose, Calif. USA

Auto ISO is a neat new feature on our cameras. But, I think it is over-used and mis-used a lot.

Auto ISO in conjunction with Manual makes for yet another type of auto exposure mode, in addition to the other AE modes we already had: Aperture Priority, Shutter Priority and Program.

Auto ISO + Manual lets the photographer choose both the aperture and shutter speed, while the camera will set an appropriate ISO. That can be useful.

In comparison, Aperture Priority (w/manually set ISO) lets the photographer choose the aperture and the ISO, while the camera automatically chooses the shutter speed. And, with Shutter Priority (manual ISO), the camera selects an aperture automatically after the photographer chooses the ISO and shutter speed. Program is a little different, allowing the camera to automatically set what it deems the best aperture and shutter, while the photographer chooses only the ISO manually.

All these can be helpful at times, can be the best mode to use depending upon the circumstance.... Program is one I only rarely use because, with two variables determined by the camera automatically, it's about the least predictable of the AE modes. You are dependent upon some software engineer somewhere designing it to automatically determine both aperture and shutter speeds that you'll be happy with, when the camera uses them. I usually only use Program for quick snaps where I don't care about depth of field and trust the camera will choose a shutter speed that's fast enough to stop any movement.

I would NEVER use Auto ISO in conjunction with any of the other AE modes: Aperture Priority, Shutter Priority, or Program. That is just layering one form of auto exposure on top of another form of AE... making for more unpredictable exposures.

To be useful, Auto ISO must have a user-settable upper limit (and possibly a lower limit, too). It also must be possible to use with Exposure Compensation, which is an essential user-controlled means of "correcting" for metering "errors" that are inherent to any reflective metering system, such as a camera must use to be able to do AE.

So I would ONLY use Auto ISO with Manual. Besides being predictable, I can see where it would be beneficial to use it in this manner. That's the same as the other AE modes, as well as full Manual only, all of which can be good choices in certain situations. In contrast, I've racked my brain and can't think of ANY circumstances where it would be the least bit helpful in any way to use Auto ISO in combination with any of the other AE modes. It would just be giving up control for no gain.

There actually is yet another AE mode.... Flash photography. With modern cameras and flashes, if using portable flash in it's auto exposure mode, even with the camera set to Manual (and Auto ISO off), it's still going to give you some form of AE. I also probably would not use Auto ISO with flash, because with flash the shutter speed is generally quite limited, and both the aperture and ISO settings become your main means of control.

JaiGieEse Loc: Foxworth, MS

That may well have been my problem, as referenced in my earlier post. I was shooting in Program mode, with Auto-ISO enabled.

Apaflo Loc: Anchorage, Alaska

User configuration error.

The "manually set" ISO value is the lowest value that Auto-ISO can choose. Set it to 100 and Auto-ISO will be able to go that low. Set it to 6400 and that is the lowest ISO that will be used.

The Auto-ISO menu lets you choose the Maximum ISO and a Minimum Shutter Speed value. But the manual ISO value previously set, or set after Auto-ISO is enabled is the minimum ISO that can be automatically set.

JaiGieEse Loc: Foxworth, MS

Well, I specified low and high-end values, as per the instruction manual. But if the camera selected a high value, it would tend to stay there. Too much chance for error. I use Program mode and set ISO as needed for my shooting circumstance.

asjohnston3 Loc: Irving, TX

I want to thank everyone for all the great advice and suggestions. It gave me a lot to think about, links to follow and things to try... This is exactly why I love UHH! Many thanks again to all!

Apaflo Loc: Anchorage, Alaska

When you "set ISO" is where the problem is!

Any time you enable Auto ISO, first "set ISO" to 100.

LoneRangeFinder Loc: Left field

I cannot imagine a scenario where I would not wish to control the ISO. Operative word here is "I"-- so it's a individual personal choice with me. I always like making this choice.

Apaflo Loc: Anchorage, Alaska

Some times that is very very true.

But more often I'm much more concerned about controlling exposure. I'll let the camera automatically adjust ISO, after I've manually set the exact exposure that I want.

amfoto1 Loc: San Jose, Calif. USA

No, it doesn't apply to Canon models from the last five years or so, either. My 7D and 5DII both have very linear noise increase, including the 1/3 ISO increments.

With earlier Canon it made some sense to use the "2/3 stop" ISO, as it would usually give a cleaner image than the next higher full stop ISO. That was the case with 30D and earlier models, certainly.

But it's not been the case for a while now.

I don't know about Nikon or any other brands at all, but with my Canon I haven't bothered with 1/3 and 2/3 stop ISOs for quite a while. My cameras are set to only use full stop ISO, which makes manually changing it quite quick and easy. With aperture and shutter speeds both set to use 1/3 stop increments I still have very fine control over exposure settings. Actually, its far more accurate than it was with most film cameras I used in the past.

Mr PC Loc: Austin, TX

No problems with the Auto-ISO on my D7200 or my previous camera, a D5200 other than if I set the max value too high, which resulted in too much noise. I wonder if, as others have suggested, that a firmware update addressed this or maybe your camera needs servicing. I've spotted refurbed D7100 bodies for $499 lately, that's very tempting for a second body that would be very similar to my D7200. Hmmm. I feel a GAS attack coming on...

asjohnston3 Loc: Irving, TX

I suffer from the same affliction... moved up from my 5100 to the 7100 about a month ago.... Factory refurb.'s were 489.00 at Adorama!! Glad I jumped when I did. They are currently out of stock & their new ones are 695.95

Apaflo Loc: Anchorage, Alaska

As noted previously, most current Canon models have at least some problem. The 7D has only one blip, which while it is a 1/2 f/stop jump, is probably not significant. The 7DII and the 5DII are a roller coaster from ISO 100 to up to ISO 400 or so. The 6D is worse. The Canon EOS 70D was announced only a couple years ago and is absolutely horrible, with 1 f/stop bumps in the dynamic range curve over the entire ISO range. (Nikon has no current models with irregularities anything like that.)

Here is a chart, cropped and slightly edited for this presentation, generated by Bill Claff's web site. The original can be seen using the URL's previously posted, which you obviously did not review.

http://apaflo.com/misc/pdf.jpg


At least not with Nikon... :-)

SharpShooter Loc: NorCal

aj, A-ISO is just another tool in the DSLR arsenal. I've been using it for years when shooting action in quickly changing light with 100% success!
I'm not sure I understand what many are saying about the camera picking too high an ISO. I know the cameras could be programed differently but I can't imagine that something so simple as one corner of the E-triangle could be difficult for either an design engineer or the camera to pick.
My camera NEVER boosts the ISO until the max f-stop has been achieved, using the lowest ISO possible. In almost all of these cases I'm using Tv because the important element is to control blur.
So what if the camera chooses something higher than we would like?! If the max f-stop is reached first, then even on manual you would have to boost the ISO to get a proper exposure, or be forced to shoot slower. Take your PICK!There is NO alternative unless you are gonna underexpose.
I have taken shots that were 10 seconds apart and one was at 3200 and the other at 400. Too many want to set a fixed ISO all the time. In my example I would have to shoot at the highest common ISO denominator, which in this case is 3200. So consequently EVERY pic will be noisy, when possibly a majority could have been at a pretty noise free ISO. If you have already frozen the action, you will gain absolutely nothing by having the camera shoot faster and faster to counter the increasing light and still retaining the noise!
Shooting A-ISO on manual is fine, but you are just in another Semi-Auto mode just like Tv or Av.
aj, I use A-ISO VERY effectively, but only when I need it and never has my camera given me an ISO surprise!!! God Luck. ;-)
SS

Apaflo Loc: Anchorage, Alaska

An excellent article!
:thumbup: :thumbup: :thumbup:

I would note too that sometimes those two shots 10 seconds apart with significantly different ISO values selected are even closer together. Auto-ISO enables getting the second shot right, where manually setting ISO would simply miss the shot.