Monday, December 21, 2009

Canon 7D Review - Focusing on Focus

As I said in a previous post, this blog is not a gear review blog. However, I just purchased a new Canon 7D DSLR and felt that I should add my two cents to various discussions that have been happening regarding this camera.

If you don't want to read about camera gear and the various arguments that photographers have about how many pixels can dance on the head of a pin, then you can stop reading right now and I won't be offended.

Some people, but certainly not all, have had issues with focusing and specifically image sharpness on the 7D. One of the more damning posts, from an image quality assessment, came from photographer Darwin Wiggett. He called the 7D "the camera we want to love". There are numerous other posts out there, particularly in the DP Review forums regarding softness issues with this camera.

Well, if this camera is so problematic, why did I purchase one? One reason I bought the 7D was to it use for wildlife photography. Though I don't do a lot of wildlife photography, it is something that clients occasionally request. My main body is a Canon 5D Mark II - a full frame body. Whereas a full frame camera gives you the advertised focal length of a lens (e.g., 400mm), a crop-framed camera such as the 7D gives you a 1.6X increase in effective focal length (e.g., 400mm = 640mm). That can be a great increase in 'reach' for relatively little money, particularly when a 600mm lens might cost $8000.

Of course, that wasn't the only reason I purchased a 7D; the improved autofocus and built-in wireless flash control were also important factors. Additionally, I knew that some people were getting outstanding results from their 7D's. I just hoped that mine would be sharp.

But I wasn't about to take that for granted, so since I received mine from B&H Photo last Thursday, I've been running tests on it.

This review focuses (no pun intended) solely on focusing and sharpness issues. Feature- and handling-wise, I think this is a great camera. But when it comes to 'pixel-peeping', it may be another story.

The first thing I decided to do was run the 7D up against my 5D Mark II.

Not a fair comparison, you say? Actually, all other things being equal, these two cameras should produce images with very similar resolutions.  The 5D II produces images of 5616x3744 pixels (21.1Mp); the 7D produces images of 5184x3456 pixels (18.0Mp). If you do the math, the 5D II theoretically produces 8.3% higher resolution than the 7D - which should not be discernible even at 100% enlargement.

Image Size Comparison - 5D Mk II/7D
The images produced by the 7D are only marginally smaller than the 5D II.


Note: all images in these tests were shot in RAW format and given default processing in Adobe Camera Raw. I did play around with sharpening, but it always introduced noise, so I considered that an unacceptable option.

Round 1: Photoshop Calls the FBI

I placed the camera on a tripod, set up a couple of flashes and took a few shots of a $20 bill in front of an old postal scale. I rarely use the scale, so it's covered by a layer of fine dust that comes in very handy in doing resolution tests.

I put the camera in One Shot AF mode, and took a bunch of photos at different f-stops. I did the same with the 5D Mark II. Even though the different sensor sizes produced a different crop, I adjusted the zoom on my lens (43mm for the 7D, 70mm for the 5D II) to give the same apparent subject size.

Relative Frame Sizes - 5D Mk II/7D
Images framed to give the same apparent subject size.

When I went open the RAW images in Photoshop, I made a very interesting discovery: Photoshop recognizes photographs of 'banknotes' and refuses to open them. It probably also reported me to the FBI. So I guess these photos might be illegal, but I swear I'm not trying to counterfeit anything!

Anyway, I ended up taking screenshots of the images at 100% in Adobe Camera Raw and then pasting those screenshots into another application that wasn't as 'sensitive' to potentially illegal activities.

One thing I wanted to test was the claim made by some that image quality for the 7D would begin to decline after about f/5.6 or so. I thought this concept was absolute bunk, so I tested the 5D II and 7D at various apertures.

All images were taken in manual mode, 1/80th sec, ISO 200, Canon 28-70mm f/2.8 L lens. The images below are 100% crops.

Canon 5D Mark II

5D Mk II f/2.8
5D Mk II f/5.6
5D Mk II f/8
5D Mk II f/11

Canon 7D

7D f/2.8
7D f/5.6
7D f/8
7D f/11

I notice two things from this test:
  1. The people who say that you can't shoot over f/5.6 with the 7D are full of it. The f/11 image is clearly (if marginally) sharper than the f/5.6 image.
  2. Holy moly, the 7D is as soft as Charmin compared to the crispness of the 5D II, particularly in the detail of Andrew Jackson's face.
Round 1 Verdict: I just wanted to toss the 7D in the trash.


Potential flaws in my technique: for this shoot I didn't move the camera, but rather zoomed the lens. Just as lens sharpness varies from aperture to aperture, it also varies from focal length to focal length, which may have affected the results.

Round 2: The Game is Afoot!

Actually, there wasn't much game afoot the day I took the 7D into the field. But I bought it mainly to use as a wildlife body, with it's fast and flexible AF and 1.6 crop factor.

Here is where I started to wonder what was up. Though it was a crappy overcast day, I got some decent shots with the 7D. The autofocus seemed sure and fast. But the results were as often horrible as they were decent.

Some shots came out nice, despite the crappy weather:

Canon 7D
1/400th, f/5.6, ISO 800, AI Servo AF (view at large size for more detail)


Others were inexplicably soft all across the image. The image below has not one single area that appears perfectly in focus. I had a number of images like this.

Soft Canon 7D image
1/400th, f/5.6, ISO 800, AI Servo AF (view at large size for more 'detail')

Those were about the only two birds I saw, but I did take a few photos of a sign in an attempt to gather more information about the camera.

Field Test Canon 7D vs. 5D Mark II
1/200th, f/11, ISO 800, One Shot Focus AF, Canon 100-400 L IS, at 400mm

Even though I had to enlarge the 5D II image considerably to make up for the 1.6X magnification advantage of the 7D, the two images returned virtually identical levels of resolution, and the 7D has noticeably more noise.

Field Test Canon 7D vs. 5D Mark II
100% crop of 7D image, enlarged crop of 5D II image (view full size for more detail)


Round Two Verdict: WTF?


Round Three: Tipping the Scales


So after that indecisive experience, it was back to the studio. This time, I tried repeating the first test, but this time without the $20 bill. I put the camera on a tripod, with a couple of flashes:

Canon 7D tests lighting Setup

The results were all over the place. Some images seemed sharp, but most were soft. I had put the camera in One Shot AF and refocused between each shot when I changed the aperture. Each time the camera locked on the center part of the scale dial.

I couldn't figure out why some images seemed tack sharp while others were undeniably soft, when I suddenly noticed in one soft image that the dust on top of the scale was perfectly sharp. The problem snapped suddenly into sharp focus (OK, seriously, did you think I could resist that? Really?): the AF was not focusing at the same point on every shot!

Here are crops of two shots, taken one right after the other:

Autofocus Issues
Both images are 1/80th, f/8, 100, Sigma 105mm macro lens

In both shots, the AF 'locked' on the center of the face of the scale, but only focused there on the first shot. The second shot is severely backfocused.

Round 3 Verdict: Aha!


Round 4: Back to Jackson

Now I had a theory to test, so I went back to my trusty Andrew Jackson $20 bill. But this time I wasn't going to photograph the whole bill - I was going to use my extremely sharp Sigma 105mm 1:1 macro lens and shoot only a tiny portion of the bill... and hope that Photoshop wasn't smart enough to tell that it was still a $20 bill.

My plan this time was to manually focus each shot, using live view at 10X to give me the sharpest focus possible. This time, I also moved the camera closer and farther from the subject in order to retain the exact same scale and framing for each camera (which is not as easy as you'd think).

I took two shots with each camera: one focused on the teensy tiny word "America" on the left side of the bill, and the other focused on the word "Jackson".

Macro Test areas
The two focus areas used for the images


The results confirmed my theory. When manually focused using live view at high magnification, images from the 7D are every bit as sharp and detailed as images from the 5D Mark II, if not more so.

Canon 7D vs. Canon 5D Mark II
7D on the left, 5D II on the right. Very difficult to discern any difference in resolution or sharpness. (100% crop for 5D II, 7D image slightly enlarged to match)


Canon 7D vs. Canon 5D Mark II
7D on left, 5D II on right. Here the 7D image appears clearly sharper than the 5D II image, possibly due to the fact that the 7D is using a better part of the lens. (100% crop for 5D II, 7D image slightly enlarged to match)

Round 4 Verdict: The sensor rocks, the AF sucks

Though it seems clear that the AF on my camera has 'issues', there are still a number of images I've taken with the 7D that are soft all the way around, with no part of the image appearing in focus (e.g., the egret photo). I don't have an answer for what's causing that.

But I do know that I have an RMA number from B&H and will be sending this copy of the 7D back. I'm hoping that the one that replaces it will have more reliable autofocus.

In truth, I almost hate to send it back since I was able to get such incredibly sharp images out of the 7D. But it took so much work to get those images, and I had so many more that were worthless, that there is no way I could rely on the 7D's AF for my daily business.

31 comments:

  1. Thanks Tony for the blog on this subject. I am an amature photographer, and just upgraded to the 7D from a 40D, mostly because of my lens collection. (2 EF-S and 1 L lens) I was having the SAME issues with my 7D, and thought I was doing something wrong. I looked into my shooting technique, and read everything I could on the subject.
    When I bought the 7D, I struggled with the decision, and I was almost ready to buy a 5D Mk II. Kinda wishing I had now.
    It was wonderful stumbling on your blog, and I am currently enjoying your site and the wonderful pics.
    Happy Holidays!
    kennyyoli@mac.com - Kenny Hyatt

    ReplyDelete
  2. Hi Tony, nice of you for doing the foot work here. I've been on the fence for a while now on the 7D. I finally got the chance to play with a friends and really like the way it feels. As for the shots, I thought they were a pretty noisy. My friend says it was because I was using the photoshop raw beta, but since I don't have the Canon raw converter there is no way I could confirm this. Next time I get ahold of a 7D I know what to look for regarding focus. Thanks!

    Regards,

    Stephen

    ReplyDelete
  3. This is the most ridiculous thing i've read. Thanks to Fake Chuck Westfall... dude, both camera's have AF microadjust, just tweak the damn camera's and quit being such a .....

    ReplyDelete
  4. I agree with your findings and from the many posts on the topic you're not alone. I'm getting ready to call Canon and arrange to have my 7D sent in for Adjustment. The microfocus adjustment is fine IF and ONLY IF the focus problem is consistent. In many cases it is all over the place so Micro adj isn't going to do squat.

    A video I shot yesterday at ISO200 of some ducks in the water at a local park has noticible vertical banding. I've noticed that some (alot) of dark areas are lacking any sort of detail and appear blotchy. Not areas that are blown out in the black but propperly exposed shadows in the entry way of a church in broad daylight.

    I have to agree with a DP comment I read that there seems to be a problem with the QC at Canon. I've had a 40D and several other DSLR's over the years and when shooting side by side with the 40D and 7D my 40D looks like a razon and the 7D looks dull. I know this isn't the case for everyone but it goes to show there is a QC issue going on.

    ReplyDelete
  5. I have for most of my Photographic life so far been a Minolta User-and have been very very satisfied,both film,and digital cameras.My last Digital ones were the A2 and the 6MP Maxxum D7.Ive waited and waited to upgrade,and decided just before xmas to upgrade.I sold all my Minolta Gear and got the Canon 7D and the G11 as a back up/walkaround camera.My first shock was although the Minolta was only 6MP its images alongside the Canon were crystal clear tack sharp!The canons were "Muddy or soft",another bigger shock was that the A2 images shot in good light were noticibly punchier than the G11!!!I even printed out a selection of images from both cameras,and let other people choose.85% chose the Minoltas ones!Please understand though the moment you start to loose light the Canon G11 floored the minolta,and the Canon G11 is an amazing camera in low light!After much arm twisting on my behalf i managed to take the 7D Canon back,I didnt even want to try another!Looks like i should have gone with my gut instinct,which was the Nikon D300s,But i got greedy with wanting more MPs!

    ReplyDelete
  6. My Canon 7D is back to the Canon Service Center for the 2nd time. Having previously owned the 10D, 20D and 40D, I attempted by all means to force the 7D to be sharp. Following comparison tests with the 40D on a tripod, using various f stops, shutterspeeds, isos, manual focus,etc., the 7D cannot produce a sharp image. I could never enlarge past a 4x6 print. Since I do large scale B&W wall art, the 7D image quality is unacceptable. I am hopeful that the camera will be returned this time with the focus problem fixed.

    ReplyDelete
  7. I've had the exact same problem as Mr. Dunn: some pictures sharp, followed by some that are extraordinarily blurry all across the image. I use three lens, all Canon (10-22, 17-55 f2.8, 70-200 f4). Same results with each lens. Some of the blurry images were taken at at f 5.6, 10, etc and at high shutter speeds. Using Canon's software, I can see where the focus point was when the picture was taken (I use single shot, single point), and focus completely missed.

    I read all about micro-adjusting each lens, but due to the inconsistency (some sharp, some blurred, picture taken right after the other, same settings) can't imagine its micro-adjustment issue.

    So Canon looked at the camera and came back with: "Your product has been examined and it was found that the adjustment of the AF assembly was incorrect causing the auto focus to operate improperly. Electrical adjustments were carried out on the AF assembly and product functions were confirmed. Cmos was adjusted to standard, other inspection, cleaning and electrical adjustments were carried out."

    Well, whatever that means, it didn't fix the camera. I'll be visiting Canon Irvine tomorrow and give them another look. This time they suggested I bring in a lens, along with camera and sample pics.

    ReplyDelete
  8. so what's the bottom line people? 7D or 5D Mk II? I've been saving for a while and thinking Canon was going to fix this problem. Buddy of mine sold all his Canon gear and switched to Nikon when his 1D Mk III was doing the same thing and Canon could not fix it. Been shooting the 40D for over a year now, and ready for a new body and transition the 40 to backup mode.

    Just not sure...

    ReplyDelete
  9. I've had the 7D for a while now, and I'm very happy with the autofocus, though it does take a bit of getting used to. Definitely better AF-wise than the 5D II - fast, responsive and accurate (given that you use single point AF and choose your points).

    However, the 5D II beats the 7D hands down on noise. My 7D shows noise even at ISO 200, which is not great. I'd say that there is a 2 stop difference in noise between the two.

    As far as choosing between the two, it depends on your needs. If image quality is your prime consideration, your choice is the 5D II. If speed and flexibility are your top priorities, go with the 7D.

    ReplyDelete
  10. I'm about ready to send my 7D back for an AF checkup - never had issues with my 10D, 5D, or 1DmkII. 7D is almost always soft. Manual focus using live view yields extremely sharp images. So I'm quite certain the AF is at fault.

    ReplyDelete
  11. This is second 7D camera I am sending back. The first one was totally whack. No focus to find anywhere on the picture, so after long and painful trying everything I could, I’ve returned it to the B&H for a replacement. This one is a better than the first one, may be that why it took so long for me to send it back . I’m still unhappy with the focus; picture quality is soft and fuzzy plus on top of that muddy. The grain seems to be very large sometimes even on 400 ISO, it looks like a gain is turn on. So, with all of this combined in one picture is not acceptable for a DSLR. For example, compare between Canon 7D with L lens with my wife’s Lumix compact camera. It is embarrassment that’s all. On top of everything, I recently found several burned pixels in a brand new camera???....

    ReplyDelete
  12. I took delivery of my 7d March 10 and using it has been a frustrating experience. Even results with still subjects are inconsistent, but I'm lucky to get one good focus out of 50 with a bird in flight. Results have been worse for my 100 - 400 mm and 70 - 200 mm L series lenses, but most photos are out of focus with other lenses. After reading this post and the feedback, I think maybe I'll contact Canon first thing next week. I thank the author of the post and the other folks who left comments.

    ReplyDelete
  13. I've been experiencing exactly the same inconsistent AF issues with my 7D. I never had any problems with my 300D or my 30D. Well....it's been back with Canon for repair for a week or so now....I really hope they resolve the issue.

    ReplyDelete
  14. I have this exact same problem as well. I'm about to send it back for a second trip. I sent it back originally after owning it for a month. Sadly, the store I bought it from wouldn't take it back at that point or it would have been returned immediately. I thought the problem was originally me adjusting to the new camera, but no... several months later and I'm trying to do shoots where half the images get tossed due to softness or complete lack of focus. I wish I could offload it, but I can't in good conscience sell it or trade it in, plus I'd lose a crap ton of money in the process.

    ReplyDelete
  15. I have had my 7D since they came out. I have loved the resolution! Compared to my 40D it is really exciting. However, this spring I've been shooting ducks. Twice, with the same situation (ducks on a pond) I have had to throw away all but a couple of the 250-300 shots! There was no point of focus anywhere. Is this a problem with the new autofocus system that uses the color sensor to participate in autofocus? I sent my 100-400 to Canon and they sent it back (after charging me $340!) saying nothing was wrong but they "adjusted it". No change. It is not the lens. Its the camera. I love the images I get when they are sharp as they should be. But, I'm seriously bummed about it when I loose 99% of my shots!

    ReplyDelete
  16. I bought the 7D and was going to use it as a back up for my Mark IIN. I was not able to get a sharp image with the 7D no matter what I did. Very soft. I returned it and now dont know what to do for a back up, because I had already given my old rebel to my daughter.

    ReplyDelete
  17. I bought the 7D a couple months ago (November 2010) and have tried to configure it with many different settings, reading information everywhere on the web and everything else and I can not get consistant results at all. Most of my images are soft or out of focus when the camera has told me it does have focus. I guess I am lucky if I get 5% good shots. I am looking at sending mine in to Canon as a fault.

    ReplyDelete
  18. This is all interesting. I've at times wondered about the AF on both my old 30D and my new 7D when I see the occasional wild AF miss or overly soft image. My problems are not constant or repeatable though, so I seem to be better off than some people who have posted here.

    Most of my poor AF experiences can be chalked up to two things: 1) Occasional user error, 2) Occasional AF miss.

    Most of the user errors I have corrected over time with improved technique. The occasional AF miss is going to happen....AF isn't perfect.

    The one place I can say for sure that the 7D truly suffers (and many other cameras do as well) is focusing in low contrast (typically indoor) situations. I have a large rate of focus errors in these situations, but still not total misses. I've cured this by shooting with my Canon external flash and letting it fire the infrared AF assist beam all the time. This has dramatically improved my AF accuracy in these types of situations.

    Other than that, I can't say that the 7D AF hit/miss rates are any higher or lower than my old 10D or 30D. They've all made mistakes at times and they've all produced the occasional overly soft image.

    One thing for sure is that the 7D images are definitely soft on its default sharpness settings, as many people have already commented. I just boosted the Sharpness setting on the Standard picture style to 5 and have never changed it since.

    Anyway, this is just my two cents...I hope everyone who is experiencing significant problems can work with Canon to get their problems resolved.

    ReplyDelete
  19. i absolutely hate my 7D. i am reading this forum because of the same issue; my images are soft, loud, and im ready to punch holes in the wall. i shoot video with my 7D, that is my primary reason for purchase. the video is so soft i am embarrassed to show the athletes i work with. bottom line, the 7D sucks!

    ReplyDelete
  20. Not sure if I should be happy or cry!? I'm glad I found this page which is describing exactly the problems I am encountering with my 7D. I have been struggling desperately with my 7D, getting mainly unfocused pictures (although a few pictures are crisp sharp) when using it with Canon's 100-400mm. Problems are less present with other lenses.
    I have sent the 7D back, the AF was recalibrated but the problem persists. I'm now stuck with a camera that is unreliable. No idea about what to do now...
    Anyway, many thanks for setting up this page, I have wasted hours in trying to figure out what the problem is.

    Greg

    ReplyDelete
  21. My 7D is going back to Canon (2nd time in a month) for service to the AF. Man, I wish I hadn't sold my 40D, it produced reliable tack-sharp images, on a consistent basis.

    The 7D, without a doubt, is a piece of sh*t camera body, and Canon should apologize to it's customers and issue a recall. I'm just one week outside my 30-day return window, and I'm ready to cry.

    This camera is pure garbage. Damn, I want that 40D back! I can't even sell this pile of crap now due to its poor reputation and shoddy images.

    Thanks, Canon, for helping me p*ss away 1,600 well earned dollars.

    ReplyDelete
  22. I got my 7D back, not fixed, Canon said it was because "the AF Assembly and the Imaging Sensor Assembly were out of position" that caused front focusing, back focusing, and front and back focusing at the same time. They said it was fixed, and nothing was wrong with the lenses I sent in. I tested it again with LensAlign and shot sets of 6 images of the same thing, with tripod, mirror lockup, one shot, remote shutter release, and got 6 different images every time. How could the camera be fixed if I got 6 different images when I was taking the same shot?!

    Very frustrating. I spoke with a supervisor, she's escalating the issue. Sent the camera and the same lenses back the 2nd time. We'll see what happens next.

    ReplyDelete
  23. This comment has been removed by the author.

    ReplyDelete
  24. This comment has been removed by the author.

    ReplyDelete
  25. If you feel you've been affected or are being affected by 7D autofocus issues resulting in soft/inconsistent images, please sign the petition here:

    http://www.ipetitions.com/petition/canon7dautofocus/

    Even if you have a working body now, but had a problem with a previous 7D, please sign!

    ReplyDelete
  26. I think I got back my 7D fixed. it was 4th time in service:( and I still need to confirm it with at least a week testing to be sure, after 1year suffer and using mostly manual focus. I can't believe that it is working now like different camera. Most surprisingly description said did comprehensive testing of all cam and cleaned censor(they needed 20 days for that, first 3 was just 10days cleaning sensor and test) Lets see if that is accidental. I am going to be happy photo enthusiast or I am going to smash it against the wall if the simptoms come back! This company should be punished in anyway for false advertisement and crappy service - denial instead fixing such expencive products!

    ReplyDelete
  27. Six months ago, i returned my 7D. Same reasons: soft images, and softer images that required agressive sharpening, and caused related artefacts. I sold the 7D and got a 5DII. Ahhhh, now I can breathe. I wholeheartedly agree with Mr. Wiggett. The 7D is well built, solid, fast auto focus, but images are invarably soft. The 7D is, mostly, a mistake, despite the fact that occasionally, it will take extremely good pics. Occasionally.

    ReplyDelete
  28. MY canon 7d sucks as well. I thought it was my sigma lens, but all this time it was my 7d :( . I haven't tried to send it to service since it is well over warranty period. Judging from other people it sounds like servicing wouldn't help anyways until the 4th try. I guess I'll try my luck and selling the thing.

    ReplyDelete
  29. Hi Tony, thanks I am very glad to have found your site. I have been very frustrated with my 7D for the lack of sharpness. I take very close up pics of gemstones and for years have used an Olympus SP-570UZ. It works great and I get great detail and sharpness, but many times my lens is ½ to ¼” from the subject and lens shadow highly restricts lighting. So I bought the 7D with the 100mm F2.8 L IS USM and found it to be great until I tried taking photos of the faceted gemstones. I have always used manual focus for the Macro shots I take, but there wasn’t one spot on any of my pics that was sharp. I tried the auto focus just in case, but the results were always identical. The lens has been great and allows for many lighting setups, but I am now using my Olympus to take the gemstone pics until I can get the 5D Mark II. One huge advantage that I miss is being able to select the lighting color temp on the 7D. I am planning on trading up to the 5D Mark II so I can retire the Olympus. I never even considered any type of issue like this when purchasing the 7D. Thanks again, Dave

    ReplyDelete
  30. Thanks for review, it was excellent and very informative.
    thank you :)

    ReplyDelete
  31. I am facing same problem and blamed everything else except 7D. Now I know the reason. Most of my images are soft. What is the conclusion... just junk it?

    ReplyDelete