Saving Photos and Resolution?

[Aggie Diver]

Hey guys,

I'm gonna show my Photoshop/photography illiteracy on this one...

How do you save the photos at a higher resolution when you take them? Is it just in the fact of whether you use TIFF/SHQ while shooting (I have a C4040), or can you go lower than that and then ratchet it up in photoshop later on (I'm stuck with 128 MB card for memory)?

Thanks.

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[archman]

Some dude just posted about this a day or two ago. To paraphrase, the only way to get nice resolution from your photos is if said photos were originally taken and saved in high resolution formats. TIF's are best, but RAW's aren't bad if your camera supports it. JPG's are still what most people use though, 'cuz they're so efficient space-wise. And obviously, a higher megapixel camera saves at higher resolutions than lower ones (assuming the settings are set the same). Some cameras can adjust the amount of compression used (if you're using compression).

You can't eke out improved resolution using post-processing software, 'cuz there's nothing to eke out. Said another way, you cannot create more detail artificially. As for enhancement, that's a whole other ball of wax.

This should be fine for you Scott, as I believe all you want to do is cut and paste supermodel bodies into your photos.

 

[Aggie Diver]

Shhh arch, this is supposed to be scuba related.

 

[scubajoe]

Is this the place for Aggie jokes Now?

Joe

 

[Gilligan]

Aggie Diver I also have the 128MB card in my C4000. I shoot my underwter photos on SHQ which gives you about 56 pics to a card. I clean them up in photoshop (not the originals) and use them on the web at 640 X 480 pixels and 72 dpi.
"Ratcheting" down is always possible but not up.
If you want to make a print or two from your photos that were taken at SHQ then open the original in Photoshop (or the like) and make the pic 4" X 6" or 5" X 7" but also allow the image to be resampled at the same time which allows the pixels to increase as you downsize the pic. The original out of the camera is around 21" X 15" @ 72 dpi or something like that. You want the print pic to be up around 300 dpi which a 4 megapixel camera can do when resized to 5 X 7. Some cropping of the pic will be necessary as the camera size is not compatible with print sizes. Save the pic as a TIFF for better print results. TIFF's make much better prints than JPEG's. A TIFF is not a compression unless you make it one. A JPEG is always a compression, just a matter of how much or how little and that's what controls its quality.

 

[Dee]

Thanks for the excellent explanation, Gilligan. Do you go the the Save for Web thing? I know I'll need to crop but is there a way to tell it that I want a 4x6 or 5x7 or whatever out of that crop rather than crop and see if that size fits. Understand what I mean?

 

[MildlyDamp]

Just a minor addition to Gilligan's comments. Even when you use compression in a TIFF, it still doesn't cause any loss of quality. The type of compression used in TIFFs is the same as used for ZIPing files, and maintains all the original data. JPEGs in contrast use a lossy compression algorithm, although in many programs the user can set the level of compression (and therefore quality loss). I've compared TIFFs and JPEGs of the same images very closely. For JPEGs which are not aggressively compressed, there's virtually no noticeable loss of quality, but you will typically get a nearly 10 fold decrease in file size.

 

[archman]

MildlyDamp, what would you say would be a good JPG compression percentage to keep high resolution?

 

[MildlyDamp]

That's hard to answer for two reasons. First, it seems like each program has a different way of specifying the compression parameters. On some programs (and most digital cameras) you just get choices like "good quality," "highest compression" and so on. Usually "good quality" or "best quality" is a good choice. In some software you actually set numeric values on compression parameters like "smoothing" and "compression." In Corel Photopaint, even setting these both at 0 will result in a substantial decrease in file size. Below 5 for each doesn't seem to make much difference in the image.

The other reason that it's problematic is that it depends on subject material. JPEG seems to perform worst on high contrast detail, like text or patterns. The effects of compression are difficult to spot on gradual changes in color or contrast, but they can also sometimes show up in large areas of solid color.

My advice is to take a high resolution TIFF file and then JPEG it using whatever options you have. Then open the original TIFF right next to the JPEG in your editing software and compare the two images at various magnifications. You should be able to discover what settings produce good results that way.