I learned about the wonders of auto-ISO when I took Steve Simon's "Mastering Your D90" workshop last year and I have been using it fairly regularly since then. I am headed for Venice and Rome next month and expect to encounter a lot of low light situations. I'd appreciate any insight and advice from anyone who has used auto-ISO on the D90.
First of all, I regularly push the D90 to ISO1600 when I need to, but I haven't gone above that. Does performance deteriorate markedly (increased noise and decreased saturation) at ISO 3200? at the H settings for ISO values above 3200? (I probably ought to try some tests myself, but I am not sure I'll have the time...hence the questions!)
Second, assuming Nikkor VRII lenses, what should I use as a minimum shutter speed to trigger auto-ISO? I'm thinking 1/30 sec would be fairly safe for most VRII lenses other than my 70-300mm telephoto. I don't think subject movement will be important most of the time. Obviously, I need a more conservative approach with non-VR lenses.
All of this assumes hand-held shooting -- even though I'll have a standard tripod and a Gorillapod with me, I know that I'll be shooting hand-held a lot of the time.
Tue 03-Jan-12 02:43 AM | edited Tue 03-Jan-12 02:47 AM by ShrimpBoy
Confession: I shoot RAW and convert with Lightroom, so I can't speak for jpegs straight out of the camera. Editing to add: I also don't use auto-ISO, I just tweak the ISO manually as needed.
Here's an ISO 1600/3200/6400 comparison I happened to shoot for myself this past Thanksgiving (click the image for the larger gallery version). Unfortunately I did not do this comparison outdoors too (it was cold!).
The images are 100% crops of an area in light shadow. ISO 1600 is top, ISO 6400 is bottom. If you look closely, the green on the cups left of the microwave gets a bit muddy at ISO 3200. It's worse at ISO 6400 and the red foil on the wine bottle has suddenly lost saturation. Noise speaks for itself but you're really only losing significant detail in the darker shadows and if you're viewing at 50% or less it's a non-issue.
>Second, assuming Nikkor VRII lenses, what should I use as a >minimum shutter speed to trigger auto-ISO? I'm thinking 1/30 >sec would be fairly safe for most VRII lenses other than my >70-300mm telephoto. I don't think subject movement will be >important most of the time. Obviously, I need a more >conservative approach with non-VR lenses.
I think this is very much dependent upon how steady you are to begin with, but what you suggest sounds reasonable to me. I wouldn't go lower than 1/100s at the long end of the 70-300.
Noise is also a function of how you use the image, as well as your skill in getting rid of it. If your image will be used to make a 24x36" print, even 1600 is probably too high if you don't do anything about it. (There's also the matter of lost dynamic range.) On the other hand, if you are downsizing to email or web, it really is amazing how tolerant we can be of noise!
If you have good software and good technique, you can make amazing strides against noise. Clearly one doesn't want to go there without necessity, but Lightroom does a pretty good job now, and external noise reduction such as Topaz DeNoise or Noise Ninja are even better. This is especially true when applied selectively.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!
Shutting on auto DSLR is like driving Mazzerati below 30km per hour. High ISO will cause u noise in low light situations. Try to keep your aperture around 2.8/4. And play with manual. You are missing way too much fun.
Just a clarification: I have been using auto-ISO to allow me to adapt rapidly to changing light situations without missing shots. Obviously, I avoid it if I have time to set things up the way I want them and if I am able to use a tripod for non-moving subjects.
As for noise -- my own experience, looking at shots in my library, is that the D90 performs quite well up to ISO 1600 especially if you take advantage of modern noise reduction programs. I have been using the DeNoise program from the NIK software suite.
>Just a clarification: I have been using auto-ISO to allow me >to adapt rapidly to changing light situations without missing >shots.
And there's nothing wrong with that, Dave. I find Auto ISO extremely useful in such situations. I would simply ignore anyone who maintains that those who make use of automation are somehow "cheating" or not making use of the camera's capabilities