 Jeanne Griffith |
Saving digital files I have been using the Canon 10D for years and saving as Jpeg for everything. I recently took the camera in for repairs and learned from the technician that I should be saving my images differently. I have been reading on the web and on this site and am very confused. I do not know the first thing about this or using photoshop. Can anyone tell me the simplest way to learn this - experimentation, books, on-line courses? I have always gone for simplicity, and do not have all the time in the world to work with images due the nature of my day job, however I suppose most of us are in that category. I mainly shoot landscapes and sandhill cranes. Please give some suggestions for this person who thought she was doing the right thing keeping it simple. I do not even know how to upload photos for this site! Thanks for any help.
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W. |
Hi Jeanne, "that I should be saving my images differently" Differently from what? What do you do now? Why is that 'wrong' according to that technician?
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Pete H |
Jeanne, Was he speaking of saving to the camera or to your computer? There are a few formats you can shoot in...JPEG, TIFF, RAW. "JPEG" being the most popular. If you are shooting in JPEG, you will "save as" *.jpg..meaning all yuor images should be saved in that format and at the highest possible quality setting. Your question is a little unclear. all the best, Pete
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Jeanne Griffith |
Okay, I am back. The tech said that if I saved my files as a Tiff rather than Jpeg I would notice significant improvement in quality. I believe he meant in the final print. I have always shot my Canon 10D at the highest quality, but not in Raw. It is loaded onto the computer as a Jpeg and that is all I do. When I do alter it slightly, I save it as a different file name, supposedly saving the original. Is there something that I should be doing that will improve the finished print?
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- Carlton Ward Contact Carlton Ward Carlton Ward's Gallery |
Hi Jeanne, If you are shooting .jpg then just save them as .jpg to keep it simple. If you decide to shoot raw, then you will want to save the images as .tif files. If you ever decide to get a little deeper in processing images, there are several courses here at Better Photo at different levels of expertise to get you going. There are some simple things that will make a huge difference in your images. Jim Miotke teaches a free course that may be perfect for you - http://www.betterphoto.com/courseOverview.php?cspID=165 Good Luck, Carlton
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Jeanne Griffith |
Thanks. I will look into that.
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Richard Lynch |
Jeanne, Let me oversimplify: * Saving JPEG is done to upload images or save file size. It has lossy compression and your files degrade each time you save to that format. * Saving in a non-lossy format (TIFF, PSD) will keep you from experiencing the loss you get with JPEG on save...there are other advantages such as saving layered corrections for adjustments at a later date. * Shooting RAW instead of JPEG (by shooting RAW it means saving the RAW captures in high-bit rather than 8-bit which has less color information) can lead to other advantages in processing. As I said, this is a bit abbreviated, but should give you the idea. I shoot RAW to maximize possibility and then save to PSD as a working version, then save to JPEG only for uploading to websites -- and discard the JPEGs after upload keeping the working version of the image so I can fashion it for other uses (e.g., print). These are the nuts and bolts, the broader ideas are hashed out in my course: I hope that helps! Richard Lynch
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W. |
Jeanne, JPG is a compressed format. When an image file is saved as a JPG it is compressed: it chucks out the least neccessary data bits (from ITS 'point of view'). So you end up with a smaller file than the original uncompressed image file. But also with less than complete data. If you open that JPG file, with less than complete data, and save it again the less-than-complete data set is compressed again. Chucking out more unneccessary bits. Again! And you are left with an image of LESS quality than that first JPG. So on, so forth. I.o.w. opening a JPG and saving it (compressing it) again gets you a lesser quality image. TIFF is a non-compressed format. Saving as .TIF does NOT affect the amount of data in the image. If you open a TIFF file, and save it again, you DON'T lose image data compared to the first one. So, if you want to retain as much image quality (data) as possible you should save as .TIF. Which is why many here shoot and edit in RAW, then save it as a TIFF with no data/image quality loss. They can edit those TIFFs again and again without data/image quality loss. So on, so forth. If they need to send that photo to someone (printers, clients, relatives, friends, etc.), or post it on some website, they open the TIFF file, save it as a JPG and send THAT. NOT the original, complete, data set: the TIFF. Because 1) a JPG is a small file, easy to upload, and 2) it makes duplication by a third party with enough image quality impossible. So that only YOU have the most perfect image file. So, edit in RAW and/or TIFF, distribute JPGs, and for long term storage, backups, use zipped TIFFs: you retain maximum image quality in small file sizes. Have fun!
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Pete H |
"Opening and re-saving JPGs deteriorates the image quality." True only if you over write to the same file name; AND if you alter the original image. Proper post processing techniques are to save the master copy and never work on it directly. You always work on a COPY; not the original. If you do alter and save the original, that would be akin to modifying a negative by drawing on it. I fail to see why anyone would work other wise? all the best, Pete
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W. |
P.S.: ONLY when your photos need to be printed in formal print work at the highest possible quality – a (coffee table) book, or something like that – you send your best edited TIFF files – but locked! – to the pro print people in question! For sending (batches of) files of UNlimited size – FREE – you can use http://www.podmailing.com/.
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W. |
Worried about security in transit? Zip those files – with password (in the prefs of your zip app) – before uploading.
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Richard Lynch |
A few clarifications: "TIFF is a non-compressed format." Actually you have various compression options with TIFF, including JPEG. Usually it is best to use LZW which is a non-lossy compression. ZIP is also a decent non-lossy choice. "if you want to retain as much image quality (data) as possible you should save as .TIF" TIFF, PSD and PDF will all retain all the file information in a working Photoshop file...It is arguable that one or two other file formats will as well. "[Opening and re-saving JPGs deteriorates the image quality.] True only if you over write to the same file name" Really it is true in any case. JPEGs are opened with previous compression, and then recompressed on save no matter what the file name. If you save the current version in stages as you work, the open image will not recompress on each save so the file you are viewing does not reflect exactly what you have stored (e.g., save-close-open will show more compression than save-save during the same editing session). I hope that helps! Richard Lynch
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Pete H |
Richard, Perhaps I missed something here? Let's assume the following: 1) I open a JPG. (dsc.001) Are you saying each time (dsc.001) is closed and then re-opened, it is being degraded? My query stems from this: If my original file resides on a (DVD read only), how is it possible to compress and recompress to such a file? The DVD will not allow "new" information. The logic seems to dictate the original JPG is completely unmolested? Did I miss something? Pete
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David A. Bliss |
Richard, while you have a lot more knowledge than me regarding print processing and file format, I am going to disagree with you. If you open a jpeg, don't do any editing, then resave at the SAME compression rate as it was originally saved, there will be no lose because the compression algorithm has already been applied, so there is no further compression. So WS, I will disagree with you about saving 10 times and seeing lose to the image. I have seen jpeg saved 100 times at the same compression level, with no editing of course, and they have no visible lose. Even if you do some editing, there might not be any further compression. Jpeg is a block compression, meaning it breaks the image into blocks and compresses the blocks. So if you have done only minor editing to a small area, the rest of the image will not under go further compression. Even the edited area might not under go further compression depending on what was done. When changing large areas, like color alteration in the sky, for instance, is when jpeg can show it's limitations, as this will affect many blocks and is a big enough change as to have additional compression added, hence the banding that is common on jpeg. (Whew, sorry about the run on!!) Pete, you are correct, and I think you and Richard are just not on the same page. For instance, if you are shooting in jpeg instead of raw, and you download the original jpeg but never save over it, it will never have any lose other than the original compression that was done in the camera. WS, you are correct about tiff, but if you want to get really nit picky, you should save the file in the software's native format (psd for photoshop). When a tiff is opened in PS, PS has to convert it to its native file type anyway, so there can be some degradation in the file during the conversion process.
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Richard Lynch |
Pete, Every save you make, the file is compressed where you save it. There is never a time where saving a JPEG does not compress. In your scenario, Hello.jpg is a re-compressed version of dsc.001.jpg with edits. dsc.001.jpg degrades only if you save when closing. SAVE is when the file takes on compression, and it is compressed if you SAVE, no matter the file name (hello001.jpg to hello100.jpeg are all re-comressed and further degraded than dsc.001.jpg). Opening has nothing to do with compression. If you are reading a file you are opening it, not saving. Whether you are reading from a DVD or hard drive reading the file does nothing to the file integrity -- you are not saving to the DVD. The 'original' is 'unmolested' but for the fact that it has already been processed from the RAW capture, and was compressed on being encoded to your digital media, as that is technically a save. Richard Lynch
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Richard Lynch |
David, You can choose to disagree, but you will be incorrect. The following is not correct: "If you open a jpeg, don't do any editing, then resave at the SAME compression rate as it was originally saved, there will be no lose because the compression algorithm has already been applied, so there is no further compression." Compression is re-applied with each save. It may be hard to see if you use high quality, but the compression happens no matter what compression setting you use, every time you save. "Even if you do some editing, there might not be any further compression." That simply is not how it works. Because the file changes during the save, when you open it again, the information in the file is different than on the previous compression and it will be compressed again based on the change in the file. I assure you it is cumulative and can be proved. Richard Lynch
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Pete H |
Wow! Somewhat confusing, but I think I am on track with you. "In your scenario, Hello.jpg is a re-compressed version of dsc.001.jpg with edits. dsc.001.jpg degrades only if you save when closing. SAVE is when the file takes on compression, and it is compressed if you SAVE, no matter the file name (hello001.jpg to hello100.jpeg are all re-comressed and further degraded than dsc.001.jpg). Opening has nothing to do with compression. "If you are reading a file you are opening it, not saving. Whether you are reading from a DVD or hard drive reading the file does nothing to the file integrity -- you are not saving to the DVD." I understand and agree that hello.jpg is recompressed on a save and suffers some degradation. BUT, the original dsc.001 should NOT be recompressed (degraded) as I am not saving this file again..It has already been saved. So is it correct to say that dsc.001 will never be degraded as long as I don't )re-save) it?..OR, is by just closing the file considered a save? I tend to think not since data can not be added or subtracted from a file on the DVD. Essentially my area of confusion here is I do not believe by simply "opening" a file and then closing it will cause degradation? The essence of this is when I give people advice concerning editing; in that they should NEVER edit the original but just save it once. When that initial save (compression) has been made, the jpg should never undergo any further degradation. Pete
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Richard Lynch |
Pete, You say: "So is it correct to say that dsc.001 will never be degraded as long as I don't )re-save) it?..OR, is by just closing the file considered a save? I tend to think not since data can not be added or subtracted from a file on the DVD. Essentially my area of confusion here is I do not believe by simply "opening" a file and then closing it will cause degradation?" Closing the file is NOT a resave (unless it gives you the opportunity to save when you close -- which suggests you made a change of some sort -- and this can happen just from opening the file depending on color settings and your management strategy). If you open and close without saving there is no degradation. "The essence of this is when I give people advice concerning editing; in that they should NEVER edit the original but just save it once." Actually better never to save it at all. That is: copy the file/duplicate it from the media off the camera instead of opening/saving even once. The file will maintain integrity when copied/duplicated (because you are not causing the file to go through compression on save), but not when opened and resaved -- not even once. I hope this helps! Richard Lynch
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Pete H |
"Actually better never to save it at all. That is: copy the file/duplicate it from the media off the camera instead of opening/saving even once. The file will maintain integrity when copied/duplicated (because you are not causing the file to go through compression on save), but not when opened and resaved -- not even once." Yep....makes perfect sense..and yes, when I shoot jpg, that is precisely what I do..right from the card to the storage media. Seems we were saying the same thing Richard, just in a round about fashion. Perhaps next we can have a discussion on converting from raw to jpg for printing? LOL Thanks, Pete
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Richard Lynch |
Fair enough Pete! David, I ran across this at the end of one reply: "When a tiff is opened in PS, PS has to convert it to its native file type anyway, so there can be some degradation in the file during the conversion process." This is not correct. File types will be interchangable as long as they support specific features and color management does not somehow come into play to cause a change. Values are still stored as RGB and each file type supports Photoshop features. Degradation happens in JPEG because of the means of compression...There is no substantial change when switching between these file types that I am aware of, and there would seem to be little to substantiate the claim that degradation occurs between TIFF and PSD formats. Richard Lynch
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