In between ISO settings?

[landscape_shooter]

<p>Hi, I just read a comment on in-between (640) etc. ISO settings not being as good as the usual settings-100-200-400 etc. Anyone care to elaborate on this? Do many of you avoid these settings? </p>

[alan_bryant1]

<p>I saw the same comment and wondered the same... I have heard that said about the L and H settings, but not the intermediate settings. I use intermediates quite often... 640 and 1250 most frequently. I haven't noticed any problems.</p>

[amol]

<p>I heard this too. However, I think, it depends on your camera. I believe the more recent models (40D/50D etc.) this is not an issue. To avoid using these, there is a Custom-Funtion setting in the menu, that allows only whole step ISO, not the 2/3 ISO. But, once again, it depends on your camera model.</p>

<p>Here is a reference, from a knowledgeable member (quote below): http://www.photo.net/canon-eos-digital-camera-forum/00UQf9</p>

<p><a href="../photodb/user?user_id=166736">Puppy Face</a> Sep 08, 2009; 03:39 a.m.</p>

<p>Yep, but this what known as a factoid: something that appears to be a fact but isn't. It depends on the individual camera. In the case of the 40D, ISO 320 is cleaner than 400; 640 is cleaner than 800 and 1250 is better than 1600. I figured this out my accident and then found good tests to back up my observations. Now my 5D was cleaner at the full stops so I never used the 2/3 stop settings. The test chart by AdamJ shows that the 40D, unlike the 5D, has better noise performance at the 2/3 stop iSO settings:<br /> <a rel="nofollow" href="http://forums.canonphotogroup.com/showthread.php?t=958" target="_blank">http://forums.canonphotogroup.com/showthread.php?t=958</a> <br /> No biggie from ISO 100-400. But at ISO 1600, in a dark church full of shadows and low mids, you'll really want to use ISO 1250 or 640 if you can. They're clearer than ISO 800 and 1600.</p>

[hjoseph7]

I have a 30D and don't have that issue not that I know of. I often use ISO 125 or 160, habits that I picked up from the film days. Indoors, I might boost the ISO to about 580, or 620 from the standard 400. Maybe now that you mentioned it, I'll have to do a double-take when using these in-between ISO values.

[scott_ferris]

<p>I disabled mine after reading this article and doing a few quick tests.</p>

<p>http://www.northlight-images.co.uk/article_pages/cameras/canon_1ds3_noise.html</p>

<p>I have a 1Ds MkIII and it does make a difference, other cameras might not work the same though. So blanket statements don't work on this one, some cameras are better with 1/3 settings some are better on whole settings.</p>

[matt_needham]

<p>Another question might be are these differences noticeable in prints, or just when pixel peeping? It makes sense to me that if the in-between ISO settings are in-camera software pushes I might be able to do it a better myself. On the other hand if I have to underexpose 4 stops and peer intently at the screen to notice the difference I don't think I care.</p>

<p> </p>

[eric merrill]

<p>I have read that, too.</p>

<p>I have not experienced that in real life prints.</p>

<p>Eric</p>

[philip_wilson]

<p>It appears to vary by body - some bodies tend not to like intermediate steps nor an ISo below the nominal design of the sensor (several of the Nikons have been worse at 100ISo than 200 ISO due to the sensor being designed for 200ISO operation). The only Canon I have used that does not seem to mind is the 5DII where ISo sensitivity appears to behave as you expect. The pop-photo test showed higher resolution at 50 ISO than 100 ISO but better noise performance at 400 ISo than 200 ISO. I have yet to test the 7D but initial impressions are that 800ISo is better than 1250 ISo which ios better than 1600 ISO (although all are quite poor).</p>

[mendel_leisk]

<p>I've heard that too. My take: it could be true that the intermediate ISO's involve some software smoke-and-mirrors. Accordingly, I just stick to the "full stop" ISO's, ie: 100, 200, 400, 800, 1600. This gives me fine enough adjustment anyways, so why risk it?</p>

[ed_hurst]

<p>Anyone have any data to show whether or not this issue applies to the 5Dii? I recall objective data a couple of years ago that showed that using an intermediate ISO was no better in noise terms than using the next full ISO stop up. But don't know if this applies to this body...</p>

[hugophoto]

<p>dpreview recently had a great article that made referance to this.</p>

<p>Part 1<br>

<a href="http://blog.dpreview.com/editorial/2009/09/sense-and-sensitivity.html">http://blog.dpreview.com/editorial/2009/09/sense-and-sensitivity.html</a></p>

<p>Part 1<br>

<a href="http://blog.dpreview.com/editorial/2009/09/moving-the-goalposts.html">http://blog.dpreview.com/editorial/2009/09/moving-the-goalposts.html</a></p>