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Old Mar 7, 2005, 11:02 AM   #1
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I recently needed to create a 60x80-pixel thumbnail for a web page. I snapped the shot at the resolution the camera happened to be set at (I think 1600 x 1200) then opened the image on a computer, cropped it to about the right aspect ratio, and scaled the image down to 60x80.

My question is, apart from saving room on the CF card, is there any advantage to setting the camera to its lowest resolution when I know the photo will be reduced to small thumbnail. For example, I wonder if I'm distorting the image in some way when I squash it using the computer software.

TIA
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Old Mar 7, 2005, 1:39 PM   #2
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Your computer, with (relative to the camera) infinite time, infinite memory, infinite computational power, and infinite electical power, will do a better job reducing the image almost 100% of the time. It will use fancier algorthms to reduce it that retain detail better and handle color and edges better.

Yes, there are probably a few odd situations where having the camera reduce it is better. I don't know of them, but they probably exist.

And how do you know that at some later date they you don't want a larger version of the image?

Eric
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Old Mar 7, 2005, 1:40 PM   #3
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I like your turn of phrase for file reduction :G

Unless you need to squeeze every bit of space out of your memory then it is usually better to not shoot the lowest resolution. Others may say that as you only need approx 72ppi for the web it wouldn't hurt to use the lowest res available. But, you might just want a bigger version as well.And the more you have to work with the better the end result will be.When all said and done you are going to have to reduce the file from the lowest setting anyway.

And no, you won't distort the image when you 'squash' it.

Regards,

Stevekin.
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Old Mar 7, 2005, 1:47 PM   #4
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Dangnabit !!!!! I think that's what some of you Americans say when you just get pipped at the post. If only I hadn't clicked on that spellchecker !

Stevekin.
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Old Mar 7, 2005, 2:05 PM   #5
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As far as I'm concerned always shoot with the highest resolution/best quality settings available if your memory card will handle a sufficient amount of photos for you. You can always reduce the size and quality (compress) in the computer but you cannot effectively increase size/quality if you shoot low res/low quality in the first place.
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Old Mar 8, 2005, 7:26 AM   #6
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I am not so sure? Can you obtain a better quality photo by using lower resolutions in VERY low light? We know a lot more about the editors we have on our computers than the software operating on individual cameras? I have read where the lower resolutions "can" make better use of the CCd, but don't ask me where?
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Old Mar 8, 2005, 7:58 AM   #7
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That is wy I said almost 100% of the time. I chose that word intentionally. There is another potential, that some operations that the camera would perform (adding contrast or sharpness) might occure before the reduction of the image. That could produce better results than doing it later on the already reduced image.

But will using better algorthms overcome that advantage? I don't know.

Or in normc's case, if they disabled photosites in such a way that the photosites used were not as near each other... . that might reduce interference between them and reduce noise. But we have no idea if that is how it's actually done. They might just use a really bad averaging technique to reduce the amount of data (and then photoshop's bicubic algorithm would be better.)

Eric
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Old Mar 8, 2005, 2:03 PM   #8
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I don't think there are any consumer cameras that disable CCDs to lower the resolution. There is some very pricey specialized professional equipment that does that. Consumer Cameras interpolate the full CCD image.

The only advantage I have heard of is that if you can get the camera to give you the exact size you need you don't have a second JPG compression. That is assuming you need it as a JPG.

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Old Mar 9, 2005, 8:23 PM   #9
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eric s wrote:
Quote:
That is wy I said almost 100% of the time. I chose that word intentionally. There is another potential, that some operations that the camera would perform (adding contrast or sharpness) might occure before the reduction of the image. That could produce better results than doing it later on the already reduced image.

But will using better algorthms overcome that advantage? I don't know.

Or in normc's case, if they disabled photosites in such a way that the photosites used were not as near each other... . that might reduce interference between them and reduce noise. But we have no idea if that is how it's actually done. They might just use a really bad averaging technique to reduce the amount of data (and then photoshop's bicubic algorithm would be better.)

Eric
If you record in TIFF or RAW, there are no circumstances where dropping resolution in the camera will yield a better result than dropping the resolution in PP. Using RAW capture, you have recorded all possible photon flux striking the sensor.

At best, in-camera processing that reduces the resolution can combine (integrate) signals from adjacent photo sites preserving the (almost all of the) total photon information that has been received. At worst the in-camera processing simply throws the information away. So anything that you do in PP to reduce resolution will be no worse than the worst case in-camera processing.

As such, I generally shoot RAW. My camera (Minolta A1) in RAW mode, has no option to record at less than full resolution. But if for some reason I were to want to record in TIFF format, I would still elect the full resolution setting.
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