 Jim Sutton |
Saving Digital Photo Files HELP! I am a novice digital photographer. I use a Nikon D100 and edit the images with Photoshop CS. (I am also a Photoshop novice.) I recently discovered that my saved edited images are about 1/3rd the size of the original, unedited images. I normally shoot the D100 in JPEG fine at Large resolution because I want to be able to make large prints at 300 dpi. For convenience, I save both the unedited and edited photos on a 200gb external hard-drive in different folders. Now I find that the edited images are too small to print as large as I'd like. What am I doing wrong?
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Wing Wong |
Hi Jim, What is most likely happening is that your images are being saved in the default quality setting for JPEG, which is somewhere between 50%-80%. So each time you edit your image and save it again, you lose 20% - 50% of your image's quality. The best way to go about saving your digital files while working and for archiving is to work with a TIFF image. The D100 supports RAW format, so once you have taken your original image in either JPEG or RAW, convert it. IF from raw, once you have your adjustments made, comit the file to TIFF format. TIFF is a lossless file format which will allow you to retain more of the information. Some programs like PS CS will support TIFF files that are 16bit/channel, so if you convert from 16bit raw to 16bit tifff and work on the tiff, you will have even better leeway to work with. Once you have finished your edits and cleanups and are ready to commit the image to a website, THEN save it to a JPEG format. But keep both the original and final version in TIFF format in case you want to do something else with it later. You should be able to retain your original images' resolution and data better that way. JPEG saves space, but does so at a great cost to quality. Hence many will recommend working with TIFF and then saving to JPEG for output, but retaining the TIFF versions. If you work almost exclusively with PS and use layers and such, keep the file in PSD format. That way, you get to keep your layers and other PS customizations. The downside of TIFF and PSD storage is that they will take up more space.
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Terry L. Long |
One thing that the previous poster forgot to mention... SAVE TO CD ASAP! I had my external hard drive crash on me recently and it would've cost $1100.00 to recover the data. However, I had just about everything on CD so the recovery wasn't worth it.
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She-She Killough |
I have a question similar to Jim's. I shoot with a Cannon D60 and always shoot in RAW and convert to TIFF, but what I don't understand is...my oringinal converted file is anywhere from 25mgs-50mgs (many 36mgs) But when I ediit them even the tiniest bit and save them as TIFF again, my files for some odd reason end up becoming 18mgs everytime? Why on earth do they do that? Also I convert from 16 bit and change it when editing in PS Element 2, to 8 bit (because you have to and because you can't keep your EXIF info if you don't)(at least I think?!) Thanks for any help!! Sheesh
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- Gregory LaGrange Contact Gregory LaGrange Gregory LaGrange's Gallery |
I didn't read the whole long answers, but if you have the window that comes up when you save a jpeg that has the 1-10 to determine what file size you want, it will come up on 10 if you save everything else at 10. But if you use the "save as" when you save after editing, sometimes the file size window will come up as a different number. So if you just automatically click to save without checking the file size, you may save it at a size smaller than you wanted. This may be particular to my version of photoshop (5.5Le). I think it may be similar for the person saving RAW to TIFF. If there's an option of saving 8 bit or 16 bit, they second time she saves, she may be unintentionally going from 16 to 8 bits the second time.
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She-She Killough |
Thanks Gregory for responding! Not sure if I was very clear. I am working on some images right now and they are big files 36 mgs most likely and they are all TIFF...I am going to edit them some and save them as a TIFF when I do that I am going to double check and see if there is a file ratio size that you can choose I am almost 98% there is not.(I know there is in Jpg) So when I edit it shrinks in mgs even though I am saving it in a TIFF. That is my problem finding out what is the reason for it going from 36 mgs to 18 just from an edit and re-save again to TIFF? Probably made that clear as MUD! Does that make sense?
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- Gregory LaGrange Contact Gregory LaGrange Gregory LaGrange's Gallery |
I know what you meant. I don't have any realistic use for tiff files, so I was trying to remember off the top of my head. I know that tiff dosen't have several options for file size, but I thought that maybe it had two bit size options.
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She-She Killough |
Yes Gregory, you are right Tiff files do have two options for bit size. But if I am remembering correctly that comes in at conversion. That is when I come out with the big file. It is the editing that shrinks it that baffles me? Btw I went to your website and I must say you have some Beautiful and amazing images there!! :D
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Wing Wong |
TIFF's that are created through RAW conversion are usually 16bit uncompressed. So a 6MP digital camera would have a 36MB file size. Each "8bit" Pixel is comprised of 3 bytes, one for each color channel. So a normal 8bit picture uses 24bits to represent each pixel. A 16bit picture just doubles that number. By default, most conversion tools will not compress an image so as to remain as compatible as possible. Saving to 8bit format will halve the file size from 36MB to 18MB. If you load a 16bit image into an imaging program and work with it in 8bit space, you will end up with an 8bit image. While TIFF doesn't have "size" options, it does have various compression format options(LZW, RLE, LOSSY, etc.) Each of these can result in a shrinking in the file size as well. *smiles* Yes, saving to CD is important. I had mentiond that in another posting, but hadn't in this one.
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She-She Killough |
Wow that is a lot of amazing information! So Wing is there a way to keep my 36 mg images 36mgs and still work them in PS? How would I do that? Thanks for your help BTW!!
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Wing Wong |
Hey She-She K, Hmm.. that depends on the version of PS that you are using. I had heard that PS version 6 and above supported 16bit images to some degree, but it was limited. I know that PS CS supports 16bit images to a much greater degree. If you want to keep working with 36MB files, ie 16bit/channel, files, then you will want to make sure of the following: - when saving files, use 16bit TIFF or 16bit PSD. PSD is preferred since it retains various layer, path, mask, colorspace, and profile information specific to photoshop. - check to see what level of 16bit support your version of PS supports. Some functions might ask you to convert to 8bit mode before that function will work. That could knock you down to 8bit mode. - Backup files at the RAW stage and 16bit stages. This will save you time if you lose files due to a computer crash. I'm still saving up for PS CS, so in the meantime, I'm using CinePaint(16bit version of Gimp) to do my post-raw file editing. I save files in XCF(Gimp file format), PSD, or 16bit TIFFs. Programs like PS elements or 3rd part paint programs which don't support 16bit may have the ability to import 16bit and put it into an 8bit format. If you use these programs, be careful not to save over your 16bit files with the 8bit ones. Alot of album software programs might do this without telling you since they are geared towards 8bit images and not 16bit images. *smiles* I think that's about it. The only other issues is that working with 36MB images might be a bit taxing on your computer, so make sure you have enough system memory.
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She-She Killough |
Wow Wing you certainly are a wealth of information! I have PS Elements 2. And I would bet that is the reason it changes it to 8 bit because it can't support 16 bit. I have never heard of the program you use Cine Paint, where do you find it? And do you like it? Thank you so much for all your help Wing!! :D Sheesh
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Wing Wong |
Hi She-She K, Thanks. :) CinePaint is what some folks call "OpenSource", that is, the program is free for downloading and use. You can download the program or the source code to the program and make changes to it as you see fit. CinePaint used to be called FilmGimp and was used by some film studios to touch up images in 16bit mode and to help with some special effects clean ups. You can get access to CinePaint at: http://www.cinepaint.org You can access Gimp at: http://www.gimp.org They have a version for Windows, MacOSX, and Linux. I like CinePaint because it lets me work in 16bit, but it has it's problems: Basically, it takes some getting used to and you will want to save often. :) But it IS free, so if you don't have PS CS and want to try 16bit, give CinePaint a try. Btw, I only check recent postings on the boards, so if you have a question, please feel free to email me through BetterPhoto's contact page.
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