What to do about ISO? Auto, or fixed setting?

[justinweiss]

<p>I'm confused about the best way to set the ISO on my Nikon D700.</p>

<p>Currently, I am using auto-ISO settings with a maximum of ISO 6400. If I'm shooting in aperture priority mode, that means the camera could give me a faster shutter speed with a higher ISO (up to 6400) or a slower shutter speed with a lower ISO.</p>

<p>How does it choose? And is this the recommended way to set ISO, or should I pick a fixed ISO setting myself, changing it as necessary?</p>

<p>Thanks!</p>

[rnt]

<p>I use auto-ISO regularly. I set the upper ISO on my D3 to 6400 or so (depending on the amount of noise I'm willing to accept) and set the aperture or shutter speed priorities to whatever I think is appropriate for the subject. I turn off auto ISO when I do panoramics or when I'm using a tripod (for instance). Be aware that manual exposure mode does not override auto-ISO. This is neither good nor bad, but just keep it in mind.</p>

[daverhaas]

<p>Justin -</p>

<p>The camera uses an algorithm to determine ISO when set in auto ISO. It will first check your Aperture (since you're in Ap. Priority, then start stepping through ISO / Shutter Speed to get to a balance that it thinks is appropriate. Auto ISO sometimes has trouble with high contrast situations (think stage lighting)... at least in my experience.</p>

<p>The recommended way is up to you. If you don't mind compromises then auto ISO is fine, or if you're shooting something where the light is changing rapidly then auto ISO is the way to go. Aother reason to use or not use is if you're like me and somewhat forgetful... I shot 5 Santa photos 2 years ago with auto iso on... Problem is that I was using a non-ittl flash so the camera thought it was shooting available light. Nothing I could do except give those families their money back and learn to check my settings.</p>

<p>The advantage of manual ISO is that you have control over it and can set it the way you want to.</p>

<p>Good thing is there's no hard / fast right or wrong answer. Play with it and see what works for you.</p>

<p>Dave</p>

 

[goad photography]

<p>Well I agree there is not a right or wrong answer. I shot mostly in manual mode. I like to keep my ISO as low as possible to minimize noise in my shots.<br>

Good Luck<br />Ron</p>

[lex_jenkins]

<p>Auto ISO is handy for low light action photography, photojournalism, candids, where getting the shot at all is the primary consideration. But for maximum quality you should choose an ISO suitable for conditions and set the exposure from there.</p>

[analox]

<p>I found this article may be useful to answer your question :)<br>

http://www.photo.net/column/jonsienkiewicz/missing-pages-column/iso-setting/<br>

Good luck!<br>

Nghia</p>

 

[justinweiss]

<p>Thanks everybody. I notice the article Minh linked to has this to say:</p>

<p> </p>

<blockquote>

<p>Leaving your camera’s ISO setting on Auto is a mistake. The camera could use a higher setting than necessary and cause your image to appear grainy or noisy. You don’t want that. Besides, you cannot accurately control the aperture setting or shutter speed setting unless you also control the ISO sensitivity.</p>

</blockquote>

<p>That's what I was starting to think, after seeing my camera pick really high ISO's for some of my shots even when there seemed to be a decent amount of available light.</p>

[lex_jenkins]

<p>One of the main problems with auto ISO, aside from the risk of increased noise and degradation of dynamic range, is that it introduces yet another variable that complicates post processing. Not a big deal if you shoot only a few photos at a time, but if you shoot hundreds of photos per session it's a hassle.</p>

<p>I use auto-ISO as an expedient to solve a very specific problem: inconsistent lighting in places like school gyms and auditoriums, or live theatre. I want the fastest shutter speed possible for a given aperture, hopefully 1/250th at f/2.8, tho' this is a luxury in most places and 1/60 @ f/2.8 is more likely (and 1/15-1/30 in theatre, even at ISO 1600). But school gym and auditorium lighting is miserably uneven, with as much as a 1 EV or more variation between pools of light directly under the fixtures and darker zones between the widely spaced lights. I don't want the shutter speed to go too slow, so aperture priority is out. And f/2.8 is barely adequate for some school gyms and auditoriums. So auto-ISO makes sense. Let the ISO vary between 800-1600. I'll batch process the shots later through noise reduction, which adjusts automatically based on the EXIF data.</p>

<p>Otherwise, auto-ISO rarely is a good choice. Whenever possible take full control of the camera settings, make it work for you. Otherwise you're getting compromised results that won't be much better than you can get with an auto-everything P&S digicam.</p>

[dbcooper]

<p>IMO, auto-ISO is useful only for shutter-priority mode when shooting quickly is primary (for wildlife or wild life), or for 'holding' a shutter speed <em>and</em> aperture in manual mode in changing light or when I can't use flash (e.g. stage lighting).</p>

<p>Otherwise, loss of control over the image quality of a shot is unappealing to me. The tail shouldn't wag the dog.</p>

 

[dlambert]

<p>I tend to keep the ISO to 100 if possible and never go above 400. Just becomes too noisy with my 40D. Why going auto if you can control, isn't that the reason why getting a DSLR? Otherwise you can easily by the most expensive point and shoot.</p>

[rene gm]

<p>Why not use Auto-ISO? You can still change the settings in P, S and A mode, until that blinking AUTO-ISO turns off, if you like.<br>

The two reasons not to use Auto-ISO is frequent use of a tripod, and a wide zoom range. It is a pitty that the Nikons cannot change the minimal shutter speed for Auto-ISO based on the focal length. Nor can they determine, if the camera is on a tripod. Are you listening, Nikon?</p>

[pete_harlan1]

<blockquote>

<p>Auto ISO is handy for low light action photography, photojournalism, candids, where getting the shot at all is the primary consideration</p>

</blockquote>

<p>I think the above pretty much covers why and when to use it.<br>

You still maintain some control by controlling the max ISO/min shutter speed you are willing to tolerate.<br>

Like some here, I do not use it as I feel it's a little gimmicky. If I can't quickly determine a proper ISO for any scene, well, I should go back to photo 101. I'm not a fan of auto anything! LOL If I were, I would have bought a P&S.</p>

<p>all the best,</p>

<p>Pete</p>

[elyone]

<p>Hmm. I like the auto ISO.<br>

I have the ISO setting in the top of My Settings Folder so I can easily change it.<br>

This is how it works - it's not magic and follows a stepwise route. <br /> You set the max ISO you are willing to go. (On my D90, I allow up to 3600)<br /> You set the min shutterspeed you want. (This depends on my lens, if I am using an 80-200, I set is on 160, if I am using a 17-55 I set it on 50.)<br /> You ALSO set your native ISO - mine is almost always at 200. This is the start-point ISO.<br /> I use A priority.<br /> (When I use flash or a tripod, I cancel the Auto ISO.)</p>

<p>Now, you are shooting a low light scene. So the camera first tries to expose using your settings. As I use 'A' priority, say I set the aperture to 2.8. On my 50mm, the camera will try to set the speed at faster than 1/50. It will always start with 200 ISO. Now, if at 1/50 and 2.8 there is STILL not enough light, only then it will start to bump up the ISO, up to 3600, until it gets a good exposure. In this case the Auto ISO will start to blink in the viewfinder letting you know that it's being activated.<br>

Now, if it hits 3600, and the light meter is still not happy, only then the camera will drop the shutter speed under 1/50. In this case the shutter speed will show up in red in the info.<br>

Better a sharp image with grain, than a smooth pic with blur because your shutter speed is too low.</p>