7D High ISO Noise & Auto ISO Questions...

[paul_russell1]

<p>My first thought was 'f8 indoors with a backlit subject?'<br>

Why f8?<br>

Then I saw it. The 18-55 kit lens.<br>

Oh well.<br>

Couple of pointers:<br>

If you spend decent money on a decent camera, put a decent lens with a reasonably fast aperture on it.<br>

A cheap 50mm f1.8 would have got you out this hole.<br>

A relatively inexpensive Sigma 18-50 f2.8 would have given you flexibility and even if you shot at f4 rather than wide open, two stops lower ISO.<br>

How did you meter? Evaluative? What about spot plus compensation? You get these useful features on a 7D.<br>

No prospect of fill flash?<br>

Lesson one is don't use auto ISO<br>

Lesson two is don't use a slow lens and / or small aperture for backlit portraiture indoors<br>

Nothing wrong with the camera, it's made the best guess for a difficult shooting situation with less than optimal settings elsewhere.</p>

[danielleetaylor]

<p><em>Also, the 7D is diffraction limited at f/7.2, due to its very fine pixel pitch. f/8 was sub-optimal for the shot.</em></p>

<p>Diffraction limits are not hard limits. While f/16 and f/22 become pretty soft for little benefit (there are few situations where they give additional useful DoF on APS-C), f/8 and f/11 are fine and sometimes necessary for sufficient DoF. A little extra sharpening deals with the diffraction induced softness well.</p>

<p>That said, f/8 was not needed in this situation.</p>

[danielleetaylor]

<p><em>"5d2 has much better noise, relatively, at high ISO. "</em><br /><em> Your graph @ ISO 3200 showed this:</em><br /><em> 26.0db/5D2 24.5db/7d</em><br /><em> "Much better"?</em><br /><em> 1.5db.</em><br /><em> Really?</em></p>

<p>I hate the dxomark site both because their tests rarely seem to match up with reality, and because even where their tests are accurate they are easily misunderstood. Suffice it to say that yes the 5D mkII does perform much better at high ISO. "Much" has to be qualified here because the 7D is still quite capable of good enlargements (8x10, 13x19, 16x20) of portraits at ISO 1600 to 3200 IF properly exposed and processed.</p>

[dan_bloch]

<p>A couple responses to the most recent responses...</p>

<p>Alot of you have questioned my using of f/8. I set this aperture because my limited knowledge and readings about photography have told me that lenses have "sweet spots" where they are generally sharpest and that they tend to be "soft" at the extremes. I thought most lenses would be very sharp around f/8 or f/11. Since the room was so bright I assumed that stopping down a bit wouldnt be a problem. Again, my fault for not checking my ISO, or factoring in that my subjects where backlit.<br>

Paul mentioned using better glass on my camera, (I was using my 18-55 Rebel kit lens). I had actually started with my 70-200 f/4 on my 7D and my Lumix LX-3 around my neck for wide angle. When I arrived at the wedding building it quickly became obvious there was no room for the telephoto because the rooms where too small. I assumed the LX-3 would give me noisier photos, so I should get all the distances I needed from the 7D. In retrospect I should have slapped on my 50 1.8 and use the LX-3 for everything else wider. <br>

Philip mentioned a camera setting where I can get the camera to show me shadows with no detail. I am unaware of this setting, can someone direct me to it? (I know how to blink the blown highlights).</p>

[paul_russell1]

<blockquote>

<p>Paul mentioned using better glass on my camera, (I was using my 18-55 Rebel kit lens). I had actually started with my 70-200 f/4 on my 7D and my Lumix LX-3 around my neck for wide angle. When I arrived at the wedding building it quickly became obvious there was no room for the telephoto because the rooms where too small.</p>

 

</blockquote>

<p>I'm not a glass snob. I proposed two modestly priced alternatives, one of which you already owned (and I own)<br>

Wrong lens, wrong settings. A lesson learned.</p>

[philip_wilson]

<p>To get the blown highlights to blink on the instant preview (or when you press the play button) select MENU then choose the second playback blue tab. The top item is highlight alert and you select enable which makes blown hilights flash black. Two items bown the list is Histogram and you can select either RGB (a histogram of each colour) or brightness which shows the total image level across the spectrum - I persionally use brightness. In order to choose your layout on the playback and instant preview screens you press the play button then the info button will toggles the various options - choose what you prefer, I like the small image, histogram and shot data layout myself.<br>

I will also completely agree with Daniel Lee Taylor on his observations on the 5DII and diffraction on the 7D. Like Daniel I have found that in practical situations diffraction is not really an issue on the 7D until about F16. I would certainly not limit my photography with the 7D to F7.1 and below (the stated F7.2 is the product of a theoretical calculation as it is impossible to set F7.2 on the 7D). I would not hesitate to use F8 to F13 and when necessary even F16.<br>

Similarly I find that the 5DII is about 1.5 to 2 stops better than the 7D at high ISOs while I know this differs from the DXO tests I find that I get ISO 1600 and even 3200 images from the 5DII that will print as well or better than the ISO 800 images from the 7D. This is obviously a subjective test with a real photographic subject. I personally do not shoot images of grey cards or whatever DXO uses. I am always intigued by their findings when you read their data points (for example when the Phase One P40 back says ISO200 it really means ISO 93!). That said if you look at their data for the 7D and 5DII you will find a 3.5 DB gap at ISO 3200 (they say the 7D is actually ISO2278 and 26.1 dB signal to noise and the 5DII ISO 2133 and 29.6dB) 3.5dB is just over a stop and closer to my observations. By the way I beleive that in digital terms it is not a signal to noise ratio but actually Eb/No that they are measuring (the energy in a bit over the noise). Other things that may explain the remainder of my observed performance difference is that at ISO 3200 the 5DII has a 1 stop better dynamic range, 10% better tonal range and 15% better colour sensitivity. Don't get me wrong the 7D is a fine camera and great value but the for non-sports use the 5DII outperforms it (as it should given the price difference).</p>

[danielleetaylor]

<p><em>Don't get me wrong the 7D is a fine camera and great value but the for non-sports use the 5DII outperforms it (as it should given the price difference).</em></p>

<p>Hate to disagree with you after you agreed with me, but...I don't fully concur with this often repeated statement. At high ISO there's no question that the 5D mkII out performs the 7D (though the 7D is still quite usable at high ISO). But at low to mid ISO there's very little difference between the two when printing up to 30". Pixel peeping will show some differences, but the 7D is capable of sharp, detailed 24" and 30" prints that stand up very well to the FF bodies when shooting at low ISO. (Incidentally, I consider 30" about the limit, from the 7D or 5D mkII, for prints of challenging subjects which will be critically reviewed at close range for sharpness and fine detail. If the subject or viewing conditions are less demanding you can naturally go larger.)</p>

<p>The point being that it's not just a sports camera. I consider the 7D to be one of the most capable and well rounded DSLRs ever produced. While shooting sports it can hang with the 1D bodies, and while shooting landscapes it can hang with the FF bodies. It really offers an exceptional mix of IQ, performance, and features, and can serve as a professional's primary body for all tasks.</p>

<p>But if you often shoot in dim available light and need to make larger prints from those files, the 5D mkII has a clear and significant edge. The 5D mkII also requires a little less work in post processing at any ISO, and is more tolerant of exposure errors.</p>

[richard_crowe4]

<p>1. I would never use auto-ISO under any circumstances. I want to be able to control the ISO I use at all times...<br>

2. The 18-55mm kit lens is certainly not a lens that is suited to available light photography because it has a relatively slow aperture (f/5.6 at its longest focal length). Additionally the f/8 you used is really not a wide enough aperture when working with available light. I would recommmend a mid-range zoom lens with a constant f/2.8 aperture if I were going to try available light photography. A constant f/2.8 aperture lens which includes Image Stabilization (or what ever term the manufacturer uses to reduce camera shake) is great for that type of photography. Using a prime lens with even a faster aperture would allow a faster shutter speed but result in a decreased depth of field.<br>

3. Your subjects are under exposed because of the white wall in back of them. You would have been better off using more of a spot metering. Underexposure will boost up noise. However a noise suppression program like Noise Ninja might help save the images.<br>

4. I am not a fan of available light photography under most circumstances but, especially when your equipment is not up to the challenge. I quite agree with Neil van Niekerk who introduces his flash photography tutorial with: "These pages were originally written to help other photographers who struggle with on-camera flash. But they were also written as a reaction against the snobbery of the purists who insist on using available light only – even when it looks terrible." <a href="http://neilvn.com/tangents/flash-photography-techniques/">http://neilvn.com/tangents/flash-photography-techniques/</a></p>

<p> </p>

[richard_crowe4]

<p>I neglected to mention... Using the built-in flash on any camera usually results in really crappy imagery. Using a hotshoe flash bounced with a reflector/diffuser (with or without a flash bracket) is, IMO, the very best way to go.<br />Get a 420EX (series) flash and learn to use it in bounce mode.<br />Get a diffuser/reflector... I personally like the Joe Demb Flash Diffuser Pro. Here is a shot that has a white background like your image but, the colors and noise is just fine. It was shot using a Canon 30D camera with a 550EX flash and Joe demb Flash Diffuser Pro.<br>

<a href="<a href="http://rpcrowe.smugmug.com/Other/Yangshuo-a/12005191_Wd7Vf#858911199_3wdQp-A-LB">http://rpcrowe.smugmug.com/Other/Yangshuo-a/12005191_Wd7Vf#858911199_3wdQp-A-LB</a>" title="T-shirt artists..."><img src="<a href="http://rpcrowe.smugmug.com/Other/Yangshuo-a/046-Tee-shirt-artists/858911199_3wdQp-L.jpg">http://rpcrowe.smugmug.com/Other/Yangshuo-a/046-Tee-shirt-artists/858911199_3wdQp-L.jpg</a>" title="T-shirt artists..." alt="T-shirt artists..."></a></p>

[dan_bloch]

<p>A new term is being used that I am unfamiliar with.<br>

"Available light photography?"<br>

This means non-flash? Or indoor? Or low light?</p>

[paul_russell1]

<p>It's a term I've heard a fair bit, and take it to mean that you work with the available light in the environment you are in rather than suppliementing it with your own source.</p>

[michael_young3]

<blockquote>

<p><em>Also, the 7D is diffraction limited at f/7.2, due to its very fine pixel pitch. f/8 was sub-optimal for the shot.</em><br>

Diffraction limits are not hard limits. While f/16 and f/22 become pretty soft for little benefit (there are few situations where they give additional useful DoF on APS-C), f/8 and f/11 are fine and sometimes necessary for sufficient DoF. A little extra sharpening deals with the diffraction induced softness well.</p>

 

</blockquote>

<p>Daniel, the diffraction limit is a hard limit, in that smaller apertures do not improve image sharpness. This is only slightly different from what you say, but an important distinction. Often, the selection of f/8 or f/11 is based on the old notion that these apertures will yield the sharpest image. They do not on the 7D, and even the 50D. Yes, I agree that the image is not severely degraded by moderately smaller apertures. They are just not any sharper than at the diffraction limit. It would be wrong to select them for sharpness reasons, because they actually yield softer images and also waste available light.</p>

[jto1]

<p>Someone mentioned this comment from Photozone above:</p>

<p><strong>Photozone says 1600 ISO "may still be useable at times" on the 7D.</strong></p>

<p>I'm not criticizing the poster of this comment since he didn't write it, but I am criticizing Photozone for publishing a completely general comment like this. Depending obviously on what your ultimate use of the photo is and what quality level you really need for the intended purpose, this is an absurd comment by Photozone.</p>

<p>I, and I'm sure many other experienced 7D users, have shot properly exposed pictures at well over ISO 3200 with very good results even at moderately large print sizes. Emphasis on "properly exposed"...</p>

<p>This is why I sometimes hate photo sites like Photozone. While they can definitely be used to provide guidance on cameras and their performance, ultimately the photographer has to pick the camera up and try it for themselves before they are dissuaded by a review that is, quite frankly, wrong.</p>

<p>This being said, I agree with Puppy Face that the logic used by the 7D Auto-ISO function needs a little improvement because it does occasionally pick an ISO that seems unnecessarily high.</p>

<p>John (<a href="http://www.johnolszewski.com">www.johnolszewski.com</a>)</p>

[phule]

<p>[[As others have suggested Auto ISO has let you down.]]</p>

<p>Auto ISO let him keep his shutter speed at something close to hand-hold friendly. It did not let him down at all, it did its job. If Dan had manually set, say ISO 400, at f/8 with that light, the resulting shutter speed would have been far too low.</p>

<p>Dan,<br>

Assuming you're not going to be printing 20x30" photos, I would not worry about the noise so much. As you've now learned, underexposing and then raising the exposure in post will only add noise, so watch out for that in the future. If you're using DPP or Lightroom, the noise can be reduced and these will print fine. I say that because having any print will be better than having no print at all, which is what the couple would have if you were not generous with your time.</p>

[elliot1]

<p>Since you shot RAW, you should be able to get pretty good prints even at ISO 3200 if you properly process them. You need really good image processing software and really good noise reduction software. What software are you using?</p>

<p>The kit lens is not really fast enough (aperture wise) to get low ISO shots indoors without flash. You compounded the problem by stopping down the lens a bit and shooting at f8. You got reasonable results for the lighting conditions you shot at and settings you used. Had you not used Auto ISO, your pictures likely would have been very dark.</p>

<p>Keep in mind that noise is really, really easy to get rid of. Maintaining as much detail as possible while reducing noise is what you need to strive for.</p>

[linda_jones1]

<p>In MHO, the auto ISO on my 7D is miserable. I've seen people shooting in perfect light with it choosing about 1600 ISO. Ridiculous overkill when you don't need it. I think the 7D will allow you to limit your ISO numbers so you can have more control. But I never use it. I shoot with a friend who has Nikon, and she struggles with auto ISO all the time. I just can't figure out why she refuses to not use it. Trial and error go a long way in improving your exposure, auto ISO won't.<br>

To add to the auto ISO problem, I also find my 7D extremely noisy compared to my MKIII. It's the one and only thing I don't like about the 7D. Even if you do choose say f5.6 over f8 it doesn't reduce the noise levels much in auto. If you want auto ISO on, try Neat Image software with the 7D and you may be very happy. Personally I minimize my ISO always, and you'll get a sharper photo, which can be lightened a stop or so, then use the Neat Image.</p>

[jto1]

<p>Hi Linda,</p>

<p>Agreed. The algorithms definitely need some work. I've also seen it pick high ISO's when it was not called for. I hope that Canon improves this with a firmware upgrade, but knowing their upgrade philosophy, they'll probably force everyone to buy a new camera just to get proper/effective auto-ISO. Bummer...</p>

<p>That being said, there are times when shooting in tricky light in quick situations when you need a desired shutter speed, and that's pretty much the only time that I use it on the 7D. Otherwise, I leave the ISO setting up to me.</p>

<p>With regard to noise....The 7D has a different sensor than the 1D, different noise reduction, etc. I'm always surprised to see people comparing cameras of any brand that way. It's like apples and oranges. They're not the same thing. </p>

<p>I've written many times on my blog about how I wish that the manufacturers would end the megapixel race and get back to sensible megapixel counts on an APS-C sensor, but they seem to have settled into the 18-megapixel range for APS-C. They could easily let that drift back down to the 13-15 range and I don't think anyone would care about the loss. The image quality is what counts and everyone wants less noise. They've been quietly reducing the megapixel counts in compact cameras over the past two years for this reason, maybe DSLR's will follow.</p>

<p>John (<a href="http://www.johnolszewski.com">www.johnolszewski.com</a>)</p>

[hjoseph7]

<p>Two years ago Canonites were clamoring over auto ISO, because all the Nikons had it. To me(IHMO) that feature belongs in the Non-Creative section just like full-auto , night-scenes, face recognition, landscape, sports etc. <br>

Not sure about the 7D auto ISO since I dont have the camera(it's in the mail) but I had all types of problems trying to use auto-iso with the 40D on the job, where I was getting crazy 3200 ISO values in bright sunlight. Then a cloud would pass by and I get another set of crazy values. </p>

[jto1]

<p>I think there are two separate thoughts going on in this thread: 1) The usefulness of auto-ISO, 2) The effectiveness of auto-ISO on the 7D.</p>

<p>In my opinion, there's no doubt that it's useful under certain circumstances. However, with regard to #2, clearly some work is needed on the algorithms. If #2 is improved, then #1 increases. Simple as that.....</p>

<p>John</p>

[michael_young3]

<p>I don't see a big problem with auto-ISO on the 7D. Just pointing it around this sunlit room, it selected reasonable values. With a 50/1.8 mounted and in Av mode, it kept shutter speed at 1/60 and 1/80, varying ISO as needed up to 3200. Shutter speed did not fall below 1/60 until ISO hit its apparent hard limit of 3200. Selecting manual mode, it adjusted ISO as needed for the dialed in exposure compensation, again limiting itself to ISO 3200. I sometimes use manual + auto-ISO for video, which I find handy for off the cuff shooting in variable lighting.</p>

<p>The problem with auto-ISO is almost certainly always user error. This discussion really should turn now to keeping vigilant watch on the information presented in the viewfinder, perhaps as much as a learning experience as making sure the camera is selecting appropriate and usable values. Since correct exposure is still so very important in getting pleasing shots, knowing innately the light level present is still an important skill to learn, even with today's automation available. For a start, learn the age old Sunny-16 rule. Today is an f/11 day. I'm headed out riding. In any case, keep an eye on the info line in the viewfinder.</p>

 

[jto1]

<p><em>"The problem with auto-ISO is almost certainly always user error".</em></p>

<p>I don't agree with that statement at all. </p>

<p>The auto-ISO on the 7D is not a big problem, but it sometimes clearly comes up with some strange choices in otherwise benign lighting conditions.</p>

<p>I completely agree with your second paragraph on all counts. A photographer should never leave too many decisions up to the camera, and auto-ISO is another example of that. It's just another tool to use when needed but probably shouldn't be left on auto-pilot. Just like metering, aperture choice, etc, aren't left on auto-pilot for advanced shooters either.</p>

<p>John</p>

[larry h.]

<p>I think the answer to this is 'no', but does Auto ISO take into account whether a lens has IS or not? I took some pictures of a Resplendent Quetzal Bird in Costa Rica in heavy shade. The ISO chosen was appropriate to give a shutter speed needed for a lens w/o IS, but as the bird was fairly still, with IS I could have gotten away with a lower shutter speed. Alas, I was so excited by the moment and trying to get the best pose that I failed to notice the high ISO. Still, the photos came out pretty well despite the ISO.</p>

<p>So, my question is, is there any way to get Auto ISO to choose lower settings when using an IS lens? Again, I think the answer is 'no', but I thought I'd ask.</p>