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

Discussion in 'Canon EOS' started by dan_bloch, Sep 5, 2010.

  1. I took some pictures at my friends wedding a couple weeks ago. There was no professional photographer and I wanted to help them document the event.
    I was shooting a Canon 7D with an EF-S 18-55, (my Xsi kit lens), in AV mode with the aperture set to F/8 and the ISO set to AUTO.
    I attached an example picture that has been converted from the RAW file with no adjustments being made, other than the exposure was raised +1.0 because it was underexposed.
    My first question is why my camera would have picked such a high ISO, (3200), as the room was well lit with a huge window and lots of sun coming through a thin, white curtain. I didn't even think to check the ISO, (which is a lesson I wont ever forget), because I assumed in such a bright room it would be fine. I suppose it is possible that I had the ISO set at 3200 by accident, but I really remember setting it to AUTO and just leaving it there, (which is what I usually do). Any other reasons the ISO might have been so high? As another point of reference, I was also using a Lumix LX-3, and in the same room with the ISO set at 400 and the aperture F/4, it produced a great exposure, (although somewhat noisy which I would expect from that camera).
    My second question has to do with the noise in the picture I attached from the 7D. The picture seems REALLY noisy to me, as do all the others taken in this room at 3200 ISO, (AUTO). These pictures are REALLY noisy, especially if you zoom in or crop them at all. One of the reasons I upgraded from my Xsi was for the ability to shoot at higher ISO. I am just wondering if there is something going on with my camera or if this is the kind of noise you would expect from a 7D at 3200 ISO?
    Thanks from a noob.
    Dan
    00XDqo-277091584.jpg
     
  2. First, The picture would be under exposed due to the white background.
    Second, The picture is noisy because you raised the exposure artificially by 1 stop.
    Solution ,You should have increased the exposure compensation in the camera during shooting. Then use bigger lens opening .
    Btw, what is the shutter speed in this exposure?
     
  3. Hi Dan, auto ISO can be extremely useful, but you do need to keep an eye on the shutter that you're achieving (if in aperture priority). If auto ISO is picking a setting that affords you a faster shutter than you really need, then you can manually set the ISO lower to gain an edge on noise.
    For example you're in AV, auto ISO, and you're shooting a more or less static subject at 100mm focal length. If auto ISO is picking say, 1600 ISO, and the resulting shutter is 1/250th, you can likely manually set the ISO to 800 and still have a fast enough shutter.
    As far as noise in this photo, doesn't look too bad, but I believe you that it probably looks worse at full size. Beyond the fact that bumping the exposure in post will make already noisy images much noisier, your goal of lower noise by switching from Rebel XSI to 7D is perhaps going to disappoint you, as they have basically the same SNR across the ISO range that they share.
    http://www.dxomark.com/index.php/en/Camera-Sensor/Compare-sensors/%28appareil1%29/619|0/%28appareil2%29/185|0/%28onglet%29/0/%28brand%29/Canon/%28brand2%29/Canon
    Granted the 7D has a higher top end, but sites like Photozone that do stringent testing of sensors are not too positive about 7d high ISO performance. Photozone says 1600 ISO "may still be useable at times." That's not a glowing endorsement.
    Personally my advice is that for a shot like this you should have been using a flash, bouncing it off the walls and/or ceiling. Not only would you have much lower noise, but likely better color and tone.
     
  4. Shutter speed is 1/40th of a second, lens is zoomed all the way to 55mm.
    I didnt know that raising the exposure in post processing results in higher noise. I thought it was considered a good, (conservative?), thing to slightly underexpose, then fix in camera RAW...?
    I am a little confused about your solution... I understand I could have increased exposure compensation, EV value), to brighten up the picture. I also could have metered it differently to get the same result, correct? But chossing a bigger lens opening in AV mode would have just resulted in a faster shutter speed and had no effect other than DOF, ... or am I missing something?
     
  5. Oh I see it now, The exif file says that you have f8, 1/40 speed and -0.7 in camera compensation at 55mm of the kitlens and AV mode.
    The biggest mistake here is the -0.7 exposure compensation.
    If it were me I'd just use P mode and auto iso, With 0 compensation, An under exposed iso 3200 image would look alot noisier than a properly exposed one. But that's just me, I hope more people that are more experienced that I am, Would chime in their thoughts and settings for this matter.
     
  6. I thought it was considered a good, (conservative?), thing to slightly underexpose, then fix in camera RAW...?​
    No, other way around. The higher the exposure the better the signal to noise ratio
    I understand I could have increased exposure compensation, EV value), to brighten up the picture. I also could have metered it differently to get the same result, correct? But chossing a bigger lens opening in AV mode would have just resulted in a faster shutter speed and had no effect other than DOF, ...
    or am I missing something?​
    Yes, it would have also given you a lower ISO, if you'd dialed the shutter back down, or opened the lens up. Again though, this should have been flashed. The light was too funky in any case. Flash, done right, would have given you much better color, and negated the noise/ISO issue.
     
  7. Brett: What you said in your first paragraph makes alot of sense, and I will be sure to keep an eye on my shutter speed and ISO in the future!
    But why would my camera have picked 3200 ISO in the first place?
    And your info about the relation to high ISO noise between the Rebel and 7D surprises me. I read the 7D review on photo.net and it said that, "At ISO 1600 and 3200 noise is still quite low but at 6400 it starts to become objectionable," and, "Overall, I’d say that the 7D has the best noise performance of any Canon APS-C sensor camera to date."
    Thank you for your advise on a flash. I NEVER even think of my flash, mostly because I have no real idea on how to use it. And I thought I would get better color and tone with natural light as opposed to flash...
    I obviously have alot of learning to do.
     
  8. But why would my camera have picked 3200 ISO in the first place?​
    Auto ISO is generally smart but isn't perfect. In your case it was actually generous in only picking 3200 given that your shutter speed was slower than your focal length.
    Thank you for your advise on a flash. I NEVER even think of my flash, mostly because I have no real idea on how to use it. And I thought I would get better color and tone with natural light as opposed to flash...
    I obviously have alot of learning to do.​
    Bounced flash can work very well for images like this. The walls and ceiling provide a huge surface to scatter and diffuse the light of the flash, so you get all the benefits of full illumination, accurate color, low noise, etc. without the harsh shadows or flat, washed out look that aiming the flash right at their faces would produce.
    Conceivably you could have gotten good color with this natural light, but it looks like funky mixed light. To me it has the typical pinkish. washed out look of a shot that probably should have been flashed. The choice of flash vs. not is a personal one, but in the heat of the moment you need to take some shots in the available light, using the best settings and technique you can, and see if the results are attractive. Then do the same with flash and decide which route to go. Otherwise you can spend a lot of time at your even getting subpar shots when a change in technique would produce much better results.
     
  9. Thanks Brett. And off-topic, your photo's are inspiring and amazing. I just spent a few minutes perusing your website. What I wouldn't do for your eye!
     
  10. I tried auto ISO for a short while and, while it was okay 2/3 of the time, about 1/3 of the time it picked a crazy high ISO. You can't really trust it if you're picky about IQ. So I turned it off and dial it in myself. With that said, 7D auto ISO is much better than 40D auto ISO, so it's slowly improving.
    And, like others have said, large areas of white or light colors will fool any meter as it expects an average distribution of tones. And weddings, snow and white sand beaches are typical places you need to override the meter by adding +.5 to 2.0 EV depending on the situation. And I agree a burst of fill flash would have helped the couple "pop" and controlled the contrast.
     
  11. Dan, I'm not smart enough to be able to interpret graphs or other data suggesting the 7d isn't much different than the Xsi at higher ISOs, but having a lot of prior experience with a Xsi and 6 months with a 7d under my belt, I'll unequivocally state the 7d is clearly cleaner above ISO800. It isn't even close in my book. I have borrowed my friend's 5d2 and believe the high ISO difference between that camera and the 7d is much closer than 7d vs Xsi.
    I've had satisfactory results up to ISO5000, generally by overexposing a full stop and backing down in Aperture.
    I would not hesitate to use ISO1600 in any circumstance.
     
  12. The camera picked ISO 3200 in an effort to make the shutter speed faster. The room was fairly bright for interior but there's really no such thing as a well-lit room, at least for photographic purposes. You'd forced f/8, you were zoomed out to 55mm so the camera probably wanted a shutter speed of 1/80 to keep the camera shake blur to a minimum. So it ramped the ISO up to 3200, and even that only got it to 1/40. In short, it did what it was supposed to do.
    The scene is difficult because it's strongly backlit, and that does tend to throw off the meter; and your -0.7 stop exposure bias is actually pushing the exposure the wrong direction. (Though, that bias did make the shutter faster and so might have prevented camera shake from ruining the photo completely... at least this way you got something.)
    Easiest thing to do would have been to use f/5.6 instead of f/8. And in the future get a fast lens if you want better shots in these situations. A 50mm f/1.8 would easily have handled this without boosting the ISO to crazy levels.
     
  13. Thanks everyone for your input. I learned alot of things from this experience including:
    1) ALWAYS check your ISO when in AUTO,
    2) I should tend to overexpose, then dial back in post-processing,
    3) Time to start experimenting with flash.
     
  14. 5d2 has much better noise, relatively, at high ISO. 7d and newer rebels are all using essentially the same sensor. The big jumps come between point and shoots and aps-c dslrs, and between apc-dslrs and full frame models like the 5d2. It just comes down to engineering realities.
    [​IMG]
     
  15. Yeah what needed to happen is one of two things. This shot needed to either be exposed correctly so that the noise would be less noticeable. OR you could easily just not shot at a constant f8.0 in this shot. this shot could have been done at half that or more depending on the focal length used and what your smallest aperture number is, all while keeping the individuals in focus. So lets just say you were shooting this shot at say f/4. You are letting a MORE light into the sensor than you were at f/8, so you can then effectively shoot the same exposure as you did above with a 1600 iso instead.
    As mentioned, the 7d does well with iso but you want to have an overexposed shot before having an underexposed shot. When you edit a high iso image that is underexposed and try to bring up the exposure after the fact, you are introducing more noise to the image. If it was overexposed, you can reduce the exposure some and the noise is less noticeable I have taken some usable images at 12,800 iso with that camera. Would i print them super big? probably not. But still very usable. its really about your exposure and also the use of some noise reduction. Also, high iso shots can look very nice in black and white (black and whites look great depending on the shot) as the high iso gives a film grain look and the color noise is not a factor (still produces "grain" in a black and white, but does not visually show the color pixels you see in the color shot). So you can always give a black and white conversion a try and see how the image looks.
    I never shoot iso auto...there is just too little control there. If shooting in Av mode which i do, alongside of manual, i set my iso based on the lighting conditions, adjust my aperture a little as needed for the type of focus (depth of field) and lighting needed and just make sure that my shutter is reasonable. All this means is that if i am indoors in similar lighting, i might get my iso to 800, 1600, 3200 if needed...and stay there until the lighting changes a lot ( i go outside, by a window, etc...) and so all i am worried about is making sure my aperture is what i want which is what you are already doing when you shoot, and making sure i have an acceptable shutter for the image i am trying to capture. This method will be a good idea to use so you don't have iso shooting thru the roof on you when you can control it by adjusting other settings.
     
  16. With regard to high ISO on the 7D, you might also check to see what the in-camera noise reduction is set on. I generally have mine set at the standard setting and get great results shooting at 3200ISO, while still retaining detail. I find the noise performance to be a lot better than the 30D I used to have and the 40D I now use for a back-up camera.
     
  17. I don't shoot weddings--I did one years ago, and that once was enough stress for me--but I would offer a couple of suggestions.
    First, yes, learn to use flash. When the background is lighter than the subjects, and you lack good lighting on the faces, flash is the way to go. If you want to avoid fancy equipment, get yourself a stofen omnibounce, maybe $15, and a Demb Flip-It, which is maybe $25 or $30. Bounce the flash, and use the flip-it to get some reflected light on the faces. For a really nice introduction to flash--both how it works, and how to use it--check out:
    Speedlights & Speedlites: Creative Flash Photography at the Speed of Light [Paperback]

    Lou Jones
    Second, turn off auto ISO. The more automatic stuff you turn on, the less control you have. Set the ISO at a tolerable level. Then it will be obvious to you if you are running low on light--the meter will call for too slow a shutter speed. You can then bump up ISO and deal with the noise, or get more light.
     
  18. Thanks again to everyone who responded and gave advise.
     
  19. Dan M's advice is key. Bounce flash will completely change your results for the better for this kind of photography. The difference is dramatic. You do need a dedicated external flash though. At a bare minimum the Canon 270 is only $140. It doesn't rotate though, it only tilts up. The 400 and 500 series flashes give you full control.
     
  20. The 7D chose ISO 3200 because no matter how bright the room appeared to your human eye, at f/8 there wasn't very much light reaching the sensor. The camera had to choose 3200 to get a 1/40s shutter speed, which is already dangerously slow for a subject which moves and that focal length, regardless of IS.
    Because you had underexposure dialed in and the subject is darker overall than middle gray, the noise in the subject is effectively worse than what you would see from a properly exposed ISO 6400 shot. (I'm betting your Lumix shot had the advantage of the subjects being lit from the front. Just because you're in the same room doesn't mean the exposure is the same every direction you point. It can be radically different with just a few degrees of movement.)
    Contrary to several of the responses, this is not evidence of poor high ISO performance on the part of the 7D or APS-C bodies in general. A properly exposed and processed ISO 3200 7D shot will make 11x14 and 13x19 prints with low visible noise. I've got ISO 2000 7D prints that show tighter grain than ISO 160 and 400 35mm portrait films show. Those were standard wedding films for years and continue to be used by some wedding photographers to this day. This is a far cry from "may still be usable at times." (Read the Imaging Resource print evaluations for a better perspective on what can be accomplished at each ISO.) Also, a 7D will show less noise in print than a XSi regardless of per pixel SNR measurements for the simple fact that the pixels are magnified less from the 7D for any given print size. So yes, it is a step up in regard to high ISO, though probably not a huge step.
    That said, APS-C in general does not tolerate underexposure well at high ISO, at least not compared to the FF bodies. And that's true of the 7D specifically. You increased exposure in post by a stop and the subject still looks dark. You desperately needed some fill light to balance out the bright background. The subject is basically more than a stop underexposed.
    Suggestions?
    * Buy and use faster glass. A 50 f/1.4 could have given a proper exposure at ISO 800 assuming f/2.8 for some DoF. You can easily make quality 24" prints at that ISO from a 7D.
    * Use bounce flash in situations like that.
    * Do not use auto ISO. Meter your scene, know what's needed, and make your own choices about the settings. (I'm not against Tv or Av, but when you add auto ISO it becomes too easy for the camera to indulge bad aperture and shutter choices. Your eye is more sensitive than any DSLR sensor. Rooms that are well lit and bright to you are not necessarily so to a camera.)
     
  21. Daniel, you are right, now that I look back at them, the Lumix shots where from the exact opposite direction and where front lit!
     
  22. I'm not a fan of auto ISO. It seems to pick a higher ISO than I think it should. For instance, I can be outside in bright light and the camera will pick ISO 200. Ive taken shots at that ISO, then drop it to 100 and the camera performs well.
    Brett is spot on with the bouncing flash. I'm not really good with a flash, but when I have experimented with bouncing flash, it amazes me how it improves the shot without blowing out the subject. I just need to use it more.
    Brett, thanks for that link. I have an XSI and was contemplating upgrading to a 7D, assuming it will have better ISO performance. Me thinks I should spend the $$ on better lenses.
     
  23. Dan
    As others have suggested Auto ISO has let you down. In my experience the 7D is very sensitive to exposure at high ISO. It is the first APS-C body I have owned as all my others are full frame or APS-H but it does seem more sensitive to exposure errors when shooting at high ISO. I find that mine is quite usable at ISO 1600 and can be used with care at ISO 3200. The difference between the 7D and say my 5DII is that you can get away with a lot of exposure issues at ISO 3200 on the 5DII and still get a good image. On the 7D I find I need to be within 1/3 of a stop of a perfect exposure and even then process quite carefully. The new metering system on the 7D is actually an improvement in backlight performance as it looks at the colours of the image. Unfortunately for those of us who have got used to the evaluative Canon metering system over the last 20+ years the 7D generally needs less exposure compensation than you expect.
    If you are shooting weddings I suggest that you do it the old way with the camera in a semi-auto mode such as Aperture priority and set the ISO and aperture to settings that give you the depth of field you are looking for and a reasonable shutter speed. Then if you find that you have to use high ISO you are aware of the need to nail the exposure. DSLRs make checking your exposure very simple - set the camera so that it shows the histogram and the smaller image after the shot and just look at the histogram. If the histogram shows spikes at either end you will immediately be aware you need to correct your exposure. You can also set the camera to flash the areas that are under or over exposed so that you do not blow highlights or lose shadow detail. In the case of your image yo have obviously blown the highlights on the wall behind the guy. Even if the exposure settings and noise were more controlled these blown hilights ruin the shot as they pull the eye towards them.
     
  24. The overall problem was not enough light on the sensor. The shot was underexposed about 1.5 stops, making it effectively about ISO 8000. Properly exposed with a wider aperture -- I feel f/4 or even f/2.8 should have been adequate -- could have delivered a shot at ISO 800 to 1200. Image stabilization and a slight assist from a monopod might bring that even lower, while still keeping shutter speed high enough for slow moving subjects.
    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.
    Existing light can be challenging, as others have pointed out. Dim interiors is one problem. Contrast range is very often an issue with average room lighting. Even outdoors especially in direct sun, contrast range is a problem. Flash often goes a long way toward solving all three, but might not always be available or even appropriate. The real solution is to shoot lots in various kinds of light. It helps to practice and experiment before having to do it under pressure.
     
  25. Brett: You say-
    "5d2 has much better noise, relatively, at high ISO. "
    Your graph @ ISO 3200 showed this:
    26.0db/5D2 24.5db/7d
    "Much better"?
    1.5db.
    Really?
    I'd say- "marginally"
    rt
     
  26. My first thought was 'f8 indoors with a backlit subject?'
    Why f8?
    Then I saw it. The 18-55 kit lens.
    Oh well.
    Couple of pointers:
    If you spend decent money on a decent camera, put a decent lens with a reasonably fast aperture on it.
    A cheap 50mm f1.8 would have got you out this hole.
    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.
    How did you meter? Evaluative? What about spot plus compensation? You get these useful features on a 7D.
    No prospect of fill flash?
    Lesson one is don't use auto ISO
    Lesson two is don't use a slow lens and / or small aperture for backlit portraiture indoors
    Nothing wrong with the camera, it's made the best guess for a difficult shooting situation with less than optimal settings elsewhere.
     
  27. 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.
    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.
    That said, f/8 was not needed in this situation.
     
  28. "5d2 has much better noise, relatively, at high ISO. "
    Your graph @ ISO 3200 showed this:
    26.0db/5D2 24.5db/7d
    "Much better"?
    1.5db.
    Really?
    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.
     
  29. A couple responses to the most recent responses...
    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.
    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.
    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).
     
  30. 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'm not a glass snob. I proposed two modestly priced alternatives, one of which you already owned (and I own)
    Wrong lens, wrong settings. A lesson learned.
     
  31. 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.
    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.
    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).
     
  32. 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).
    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.)
    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.
    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.
     
  33. 1. I would never use auto-ISO under any circumstances. I want to be able to control the ISO I use at all times...
    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.
    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.
    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." http://neilvn.com/tangents/flash-photography-techniques/
     
  34. 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.
    Get a 420EX (series) flash and learn to use it in bounce mode.
    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.
    <a href="http://rpcrowe.smugmug.com/Other/Yangshuo-a/12005191_Wd7Vf#858911199_3wdQp-A-LB" title="T-shirt artists..."><img src="http://rpcrowe.smugmug.com/Other/Yangshuo-a/046-Tee-shirt-artists/858911199_3wdQp-L.jpg" title="T-shirt artists..." alt="T-shirt artists..."></a>
     
  35. A new term is being used that I am unfamiliar with.
    "Available light photography?"
    This means non-flash? Or indoor? Or low light?
     
  36. 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.
     
  37. 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.
    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.​
    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.
     
  38. Someone mentioned this comment from Photozone above:
    Photozone says 1600 ISO "may still be useable at times" on the 7D.
    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.
    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"...
    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.
    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.
    John (www.johnolszewski.com)
     
  39. [[As others have suggested Auto ISO has let you down.]]
    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.
    Dan,
    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.
     
  40. 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?
    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.
    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.
     
  41. 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.
    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.
     
  42. Hi Linda,
    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...
    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.
    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.
    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.
    John (www.johnolszewski.com)
     
  43. 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.
    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.
     
  44. 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.
    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.....
    John
     
  45. 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.
    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.
     
  46. "The problem with auto-ISO is almost certainly always user error".
    I don't agree with that statement at all.
    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.
    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.
    John
     
  47. 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.
    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.
     

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