7D: 20 shot flight series

[Doug Brown]

I had a brief but exciting encounter with a Green Heron while field testing the 7D. The flyby lasted only 7 seconds and I managed 20 frames against 3 different types of BGs; sky, green vegetation, and water. I thought this might be a good way to evaluate AI Servo performance with a fast-moving target against a variety of BGs. Of the 20 frames, I counted 10 that were tac-sharp, 6 that were sharp, 1 that was soft, and 3 that were OOF. I've done no post-processing to these images. They were exported untouched from Lightroom to Photoshop, where I cropped and resized for web posting. No sharpening at all. The series was shot hand held with a 500mm f/4 lens.

[Doug Brown]

Frame 1: tac-sharp

[Doug Brown]

Frame 2: tac-sharp

[Doug Brown]

Frame 3: tac-sharp

[Doug Brown]

Frame 4: sharp

[Doug Brown]

Frame 5: sharp

[Doug Brown]

Frame 6: tac-sharp

[Doug Brown]

Frame 7: sharp

[Doug Brown]

Frame 8: sharp

[Doug Brown]

Frame 9: tac-sharp

[Doug Brown]

Frame 10: OOF

[Doug Brown]

Frame 11: OOF

[Doug Brown]

Frame 12: OOF

[Doug Brown]

Frame 13: sharp

[Doug Brown]

Frame 14: tac-sharp

[Doug Brown]

Frame 15: tac-sharp

[Doug Brown]

Frame 16: tac-sharp

[Doug Brown]

Frame 17: soft

[Doug Brown]

Frame 18: sharp

[Doug Brown]

Frame 19: tac-sharp

[Doug Brown]

Frame 20: tac-sharp

[Joerg Rockenberger]

Impressive. Thanks for sharing. JR

[openthreads]

Nice! Question: Can you give us an idea of how heavily these images were cropped? Thanks.

[Morkel Erasmus]

thanks for posting this Doug - it seems that your 7D hasn't got a problem with keeping focus on the bird against high-contrast BG's. makes me excited!

[jpons]

Doug,

My experience for the 7D is very similar to yours. I have found the AF to be superior to every other Canon EOS camera save for the 1D series (1DII, 1DIIN, etc)...

-J

[Axel Hildebrandt]

How much did you crop them and I assume they are all at ISO 400, right?

[Doug Brown]

All were shot at ISO 400 in aperture priority mode with focus point expansion enabled (using the central grouping). Because I was shooting in Av mode, my shutter speed dropped from 1/2000 to 1/800 when the bird was flying against the varied BG. Here's a full frame from the sequence.

[Michael Pancier]

Doug, what were the CF settings you used?

As far as the Af setting, did you use the cross center or the small square zone?

[Doug Brown]

And here's a link to the cropped and processed version of the uncropped original.

[Mike Lentz]

My friend I am sorry... I find these images to be soft and noisy (the noise might be because of the heavy crops) I am surprised (very) that you would title these sharp and tack sharp. I would personally bin them. Sorry, but if honesty is what we want, thats my .02 worth.

[Dan Brown]

Cool series and final product Doug! I greatly appreciate your efforts to inform us!

I know this has nothing to do with the your new 7D, but, you mention that the SS dropped on some of the shots due to the BG. Were the shots made at the lower SS also the OOF or only "sharp" shots? If so, using Jim Nieger's manual exp method might (probably IMO:)) have produced more tac sharp images! And, if you had shot in manual, you could have produced a multi-image pano stitch! Just some thoughts:).

[Doug Brown]

You are entitled to your opinion Mike, and I appreciate your honesty. These are straight RAW to JPEG conversions with no processing at all. Here's a link to a processed image (frame 14) posted in the Avian forum. I think it's pretty sharp, and I could get the same results with the other images that I labeled tac-sharp in this thread. This thread was intended to be about AF performance, not overall image quality. Again, thanks for your input.

[Morkel Erasmus]

Mike - my .02 as a relative newcomer to DSLR photography would be that the full size images are sharp - and Doug correct me if I am making the wrong assumption - but Doug has stated that he resized it for web but didn't apply sharpening. It is a well-known fact that resizing causes softness if you don't do some slight sharpening after the fact.

[Morkel Erasmus]

okay I see Doug has responded in the same vein :)

[Michael Eckstein]

My friend I am sorry... I find these images to be soft and noisy (the noise might be because of the heavy crops) I am surprised (very) that you would title these sharp and tack sharp. I would personally bin them. Sorry, but if honesty is what we want, thats my .02 worth.

The OP stated these were not sharpened and very heavyily crroped. I took an image in Photoshop and applied sharpening and it was very sharp. I'm sure a closer to full frame shot would have been sensational!! I'm impressed and ordered a 7D. Thanks for the images.

P.S. Mike Lentz I visited your website and you certainly have some beautiful images!!!

[Manas Khan]

Great series Doug. Thanks for sharing.
Loved the processed image!

[rherteux]

I have to agree with Mike on this one. Since the tac sharp images are indeed sharp I don't think it's about resizing for the web. The ones you label as "sharp" are to my eye still softer than I would like to see from this camera. I was really hoping to see more "tac sharp" images. How would you say it compares to your 1D Mk 3?

[Axel Hildebrandt]

The fact that Doug posted images of a bird that does not nearly fill the frame is quite helpful. If it were closer chances are that most images would be in focus. To me it's much more interesting to see how the AF system works if the subject is not close and the BG varies. It is to be expected that a heavily cropped image made with an 18MP, 1.6x crop sensor at ISO 400 is somewhat noisy out of the camera.

[arash_hazeghi]

Are these resized or 100% crops? I guess sharpness is to some degree subjective as well, for example I don't find frames 4,7,8,13 and 18 sharp, to me they look soft especially if they have been resized. It would be more helpful to post 100% crops.

To me the really sharp ones are 1,2,9,15,16,19 and 20 still less than 50% of the sequence.

This is still better than the results I got with raptors but I suspec this is due to the fact that the bird is flying in a straight line while you are panning and tracking as opposed to birds that erratically bank to the left and right and wobble as they fly.


Thanks for sharing these, I returned my 7D and ordered a new one, I will post more tests with the new camera when it arrives.

[Charles Glatzer]

Doug,

I appreciate the effort, but I cannot utilize the images as posted to determine the cameras critical AF acquisition capabilities. I can only judge whether one image is sharper than another in the provided sequence. Additionally, I would only be making assumptions on its tracking IQ w/o knowing where the sensor was placed on the subject in each frame at the time of shutter release. It is a difficult task to judge an image for critical sharpness out of the camera on the web, as the variables are many.

Again, I appreciate the effort.

The image in the provided link appears to be focused mid-wing and not on the head.

Respectfully,

Chas

[arash_hazeghi]

Mike - my .02 as a relative newcomer to DSLR photography would be that the full size images are sharp - and Doug correct me if I am making the wrong assumption - but Doug has stated that he resized it for web but didn't apply sharpening. It is a well-known fact that resizing causes softness if you don't do some slight sharpening after the fact.

This is not entirely correct,first of all it depends on the down-sampling algorithm used, secondly PhotoShop and Lightroom use bicubic interpolation for downsampling by default, if a photo is razor sharp down-sampling will result in a slightly softer image but if the original is slightly soft or oof downsampling can hide the imperfection.

here is an example

100%

[arash_hazeghi]

Downsampled in PS using bicubic method and no sharpening



resized appears better than 100%. When evaluating sharpness, noise etc. image has to be inspected at 100% or 1:1 sensor output, anything else is either interpolated or extrapolated.

[Doug Brown]

I agree with you Axel, and that was my point in posting this series. To get 16 workable images in a series of 20 frames taken over 7 seconds, especially when your subject is flying against 3 different types of BGs, says some pretty good things about the camera's AF system IMO.

[arash_hazeghi]

The fact that Doug posted images of a bird that does not nearly fill the frame is quite helpful. If it were closer chances are that most images would be in focus. To me it's much more interesting to see how the AF system works if the subject is not close and the BG varies. It is to be expected that a heavily cropped image made with an 18MP, 1.6x crop sensor at ISO 400 is somewhat noisy out of the camera.

Axel, visible noise is really lower than 50D, the issue here is lightroom does not support 7D yet, it is a beta profile. If you use DPP you will find that noise is not an issue at all. To Canon's credit 7D IQ is very good given its tight pixels.

Here is an example ACR vs DPP ISO 400. You can make perfectly usable tight crop photos with the 7D if AF is spot on.

[Jim Fenton]

Well, I haven't read through the posts yet so I'll state my thoughts before they get tainted :)

First observation is relative to sharpness. In all honesty, I'm not seeing the level of sharpness that you are Doug. In one of the images at 1/2000 and f8 that you're referring to as tack sharp, it's looking softer than it should especially at that SS.

Also, for ISO 400, the water background appears fairly noisy on my end, although it is really fine grained and I'm sure it would easily clean up.

Of course, I can't say exactly how my images would have compared had I been shooting side by side with my gear, so this isn't a comparison...simply my observations.

In regards to AH's comparison between DPP and LR, while the DPP image is less noisy, it is also softer.

Just my observations.

[Ed Cordes]

Doug, thanks for posting this series. To me, the 100% crop images with out any processing look impressive. This is better than I could have gotten with my current gear. {aging 1DMK2 [non N] and 40D}. I think some forget that these are nonprocessed postings. It is also important to remember how small the subject is in the un-cropped frame.

I have yet to have an opportunity to test BIF with my 7D, but the static images I have made are super. The noise is easilly controlled with Noise Ninja up to about ISO 1250 for printing up to 13 X 19. Of course, this is just my opinion and others may disagree. That's what makes the world go 'round.

[Flavio Rose]

Based on the full frame image posted by Doug, the corresponding image in the sequence of 20 (which I think is image 14) appears to be reduced in size relative to a 100% crop by a factor of a bit less than 2:1. My guess -- based on how much of the full frame the bird occupies -- is that at 100% that image is very roughly 1900 pixels wide, versus 1024 pixels here. Thus, image 14 at least is not a 100% crop, and I suspect the others are not either.

Thanks to Doug for this highly informative post.

[Doug Brown]

Here's what I mean when I use the term 'sharp' as opposed to 'tac-sharp.' IMO 'sharp' images are ones that look good after processing. In my workflow, soft and OOF images go in the dumpster, but if 'sharp' images have photographic merit, I'll process them. 'Tac-sharp' images are sharp from the unprocessed RAW stage onward. This is a processed version of frame 13, which I labeled as 'sharp.' I think it does pretty well with some NR and sharpening.

[Doug Brown]

I've got plenty of very sharp BIF RAW files from my first week with the 7D (much sharper than these images). But I normally fire off 1-3 frames at a time during flight photography. This happened to be a rare instance where I tracked and photographed the bird for a prolonged period of time against a variety of BGs; that's why I chose this series to post here. I think it tells you much more about AI Servo AF than does a 3-shot burst where the bird occupies 3/4 of the frame.

[Mike Lentz]

Interesting thread actually. I'm not sure I've ever seen a thread on "sharp non processed" images and therefore am not an expert. I do believe you do fine work, but man did my eyes and mind jump when I saw that you called alot of these images sharp or tack sharp. I really wonder how this camera compares to other "non processed" images. I think its a tough test do an such a heavily cropped subject. I think the last image looks the sharpest and therefore I deduce that all that cropping and loss of pixels kills the image.

P.S. Thank you Michael Epstein for the fine compliment.