A experiment regarding IQ of web images - feedback requested

Started Dec 5, 2009 | Discussions thread
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gdanmitchell Veteran Member • Posts: 7,730
A experiment regarding IQ of web images - feedback requested

Recent discussion here* focused on the important of using a high end full frame camera for shooting images destined for display as small jpgs on the web. Or, stated another way, it focused on the extent to which the quality of the original full size file is visible in reduced size/data versions created for the web.

(* http://forums.dpreview.com/forums/readflat.asp?forum=1032&thread=33810372 )

I would like to ask you to participate in a little experiment related to this question. Here are three files. There are three possibilities:

  1. All three jpgs come from identical files - e.g. they are identical as presented here.

  1. All three jpgs are from different original files - e.g. they are all different as presented here.

  1. Two jpgs are from identical original files and one is from a different original image.

I'll stipulate that the conversion from photoshop to jpg was the same way in all three cases, no matter which case it turns out to be. Also, the question is not whether they came from the same shot or not, but whether the original image file(s) from which the jpgs were produced are same/different. (So, for example, whether or not the crop is identical or whether or not the water is the same in all three is not the question.)

Which is it - option 1, option 2, or option 3?

For those who care to speculate further:

  1. If you think that they are different (you select either option 2 or option 3), what difference(s) do you see and in which images?

  1. If you think that two are the same (you select option 3) which one is different from the other two, and in what way(s) does it differ?

It is easily possible to cheat, but that invalidates the exercise, right? No fair looking at the files directly and no fair checking EXIF or other file info - you should only view them on screen in your web browser since that is the point of the question. (The file names were chosen to obscure information that might offer hints and/or due to web URL requirements.)

After we see a few responses I'll reveal the correct answer.

Here are the three examples:





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G Dan Mitchell - SF Bay Area, California, USA
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