Upload & Sell: Off
Well I was 2/8 which is poor. I made my guesses based on my perceived measure of noise, since the 7D, when criticized, is generally most often panned in this regard. I guess by choosing so poorly it affirms that any modern camera can produce fine online photos in the hands of a capable photographer - although I had accepted this premise long before just embarrassing myself with my poor showing
You mention "on line" photos. While I agree that small web-sized photos don't always tell the full story, I can assure you that, in this case, had you been looking at prints, there would have been very little difference in the ease of making accurate guesses. I have prints from photos documenting the progress of that young eagle taken virtually every day for 6 months from when it was still an egg to the last time I saw it 2 months after it left the nest. Without knowing which kinds of shots I took with which camera/lens combination and without access to the file information, I would be guessing completely if I had to tell you which of the prints were from the photos from which camera/lens.
Also, the files with both combinations received the same minimal processing, which consisted of minor exposure adjustments, if needed, to the raw files before conversion and minor shadow and/or highlight adjustments, selective USM, and cropping to the desired final composition of the converted TIFFs.
I'm confident that I could more easily guess which photographer took a picture than I could guess what equipment was used to take a picture. For example, I have been looking at Tony Markle's pictures on FM for many years. The kinds of pictures he takes, the composition, the processing, etc. are very distinctive, and I think I could tell with a high rate of accuracy which pictures were his out of a group of pictures taken by various photographers, but I would have no confidence in guessing what cameras and lens he used for what pictures.
I'll reveal which equipment was used for each of the pictures I posted earlier.
The first picture of the young bird stretching its wings in the nest was taken with the 500 and 1D Mark IV.
The second picture of the bird with tight framing and a sky background was the one taken with the 400 DO plus the 1.4x and the 7D. Again, perhaps my 500 could have done better, but what I got there is more than good enough to satisfy me.
The third picture of the bird flying with trees in the background was taken with the 400 DO and the7D. It was one of the ones with the most severe crop.
The 4th picture with the bird sitting on a light fixture was taken with the 400 DO and 7D.
The 5th picture with the youngster startling the parent with its practice flying was taken with the 500 and the 1D Mark IV.
The 6th picture with the bird just after a take off from a tree was with the 400 DO and 7D, and it was also a fairly severe crop.
The 7th picture with the young bird and a parent in the nest was with the 500 and 1D Mark IV.
The 8th picture with the young bird pushing off from the roost with a somewhat cloudy background was with the 400 DO and 7D, and it was also a fairly severe crop.
Also note that the pictures taken with the 500 should have started out with image quality advantages because they were all taken off of tripod, while the 400 DO pictures were all hand held, and, also, the pictures from the 500, in general, were cropped less than those from the 400 DO.
Once again, I don't think that the differences in the image quality of what you get from different equipment are nearly as great as you would be led to believe from reading the posts of those who tell you how the performance of one lens or body might "blow away" the performance of another. And I think that I would be making a big mistake if I did not make my lens (and body choices) on a wide range of factors relative to my shooting needs. I have little need, for example, for 300 mm. If I did have a need for that focal length, I would choose a 300/2.8 lens and put up with how much it weighs relative to its focal length. On the other hand, if I need 400 mm, it is an easy choice for me to take the 400 DO and to get the benefit of its light weight.