I'm currently looking to buy a high quality camera but I'm looking to learn more about the image types. I know that TIFF and RAW are the best because they do not have an compression. Reading the Sony forum though, it says the TIFF images take a really long time to record. Is this also true with RAW files on other cameras? I'm going to print mostly 4x6 pics but I want to be able to print 8x10 with exceptional quality as well. Can JPEGs produce good enough quality for 8x10 photos? If so, why are the non compressive file types even used?
-
Welcome to the new forums! Please read this first. For known issues we are working to resolve, click here.
raw/tiff/jpeg
- Thread starter Botagrox
- Start date
Nils Haeck
Forum Enthusiast
JPG with high quality settings should do the trick. However, if you upsample these images really far, you might notice some artifacts.
Jpg2000 is even more promising, since the artefacting is reduced significantly.
The reason why most people want to store the original, or at least an uncompressed version, is that when you repeatedly open/save the same JPG, the quality will degrade further and further (each time some quality is lost).
Nils
Nils Haeck
Developer of ABC-View Manager (image management software)
http://www.abc-view.com
Jpg2000 is even more promising, since the artefacting is reduced significantly.
The reason why most people want to store the original, or at least an uncompressed version, is that when you repeatedly open/save the same JPG, the quality will degrade further and further (each time some quality is lost).
Nils
--
Nils Haeck
Developer of ABC-View Manager (image management software)
http://www.abc-view.com
bruce komusin
Senior Member
- Messages
- 1,127
- Reaction score
- 0
Using commonly-available CCD sensor technology, the entire CCD array is covered with a color filter composed of tiny color elements, like a patchwork quilt. Each pixel in the sensor has its own color filter and responds to only one of the colors R, G, or B. The intensity of light at each pixel sensor represents the RAW data, which has basically 8 bits of info for each pixel.
An algorithm inside the camera or the computer can then interpolate that RAW info (if it also knows which color and what the color filter parameters are) and compute the estimated R,G,B values at each pixel site -- and that's the uncompressed TIFF data. The TIFF data is three times as large as the RAW data since it is composed of three intensities, in other words 3 * 8 = 24 bits of info for each pixel.
Then again, an algorithm inside the camera or computer can compress the TIFF data into JPEG data, and that reduces the number of bytes by about one-tenth their original number, i.e. to about 0.3 times the number of RAW data byes -- but with some loss of quality, however it is usually unnoticable.
That is why TIFF images take the longest time to record, then RAW, then JPEG take the shortest time of all. Because the time to record is directly proportional to the number of bytes.
-bruce
An algorithm inside the camera or the computer can then interpolate that RAW info (if it also knows which color and what the color filter parameters are) and compute the estimated R,G,B values at each pixel site -- and that's the uncompressed TIFF data. The TIFF data is three times as large as the RAW data since it is composed of three intensities, in other words 3 * 8 = 24 bits of info for each pixel.
Then again, an algorithm inside the camera or computer can compress the TIFF data into JPEG data, and that reduces the number of bytes by about one-tenth their original number, i.e. to about 0.3 times the number of RAW data byes -- but with some loss of quality, however it is usually unnoticable.
That is why TIFF images take the longest time to record, then RAW, then JPEG take the shortest time of all. Because the time to record is directly proportional to the number of bytes.
-bruce
Petteri Sulonen
Forum Pro
High quality JPG holds to all practical purposes exactly the same resolution as RAW or TIFF. Print size isn't an issue. TIFF is marginally better than JPG-SuperFine, but you really have to be a loupe jockey to see the difference. RAW only gives better results in really difficult conditions (lighting, contrast) because it captures more data and gives you more latitude in compensating for that. For most normal purposes, JPG Fine is more than good enough.
Petteri
--
http://www.seittipaja.fi/index/
Dewdrop1
Leading Member
You need to specify the camera when you make file size comparisons. The Minolta Dimage 7i (5 megapixels) uses a 12 bit A/D converter to capture the RAW data. For some reason, Minolta has chosen to use 2 bytes of storage for each sensor rather than 1.5. This means that the TIFF files are only 1.5 times the RAW files, roughly 15 MB and 10 MB, respectively. Basically, you are correct. TIFF does take the longest time, followed by RAW and then JPEG. The highest quality full resolution JPEG file from the 7i is in the range of 2 to 2.3 MB and is hard to tell from the TIFF or RAW images.
One other point (I believe you touched on this): the purists want the data unprocessed in any way by the camera. They then use photo shop to edit the image to the colors, contrast, sharpness, etc. that best suits them. So, unless you are into that much control, high quality JPEG is fine.
DEWDROP
R
Rinus Borgsteede
Guest
I also think that a jpeg saved at a 10 setting does not really look any different to the observer but there are differences that become a problem later. Jpeg compression groups pixels together that are close to the same value. depending on the setting for compression you use, it does it more agressively. When you open a tif image in Photoshop 7, and you try to save it to a jpeg, the preview window will show the differences. At the lowest setting, the quality is totally useless but at the 10 setting niobody can see the difference. When you edit your jpeg image and lets say you increase the contrast, you are no longer just changing individual pixels but you are changing little blocks of pixels. These were the image blocks that were crated to reduce data during storage. No amount of counter measures are helping to bring back the individual pixels. To say that it does not affect print sizes is essentially correct but it better be the post processing image you save to a jpeg or irreversible damage will occur. There is no problem if the edited file was saved before compressing to a jpeg but a jpeg from the camera is already doomed unless no further editing is going to be done. Now, everybody relax because the Fine mode makes a pretty good image on most cameras and I would certainly use it for most editorial magazine work but if the end result is to be your masterpiece on a large print, you better think twice.
Rinus of Calgary
Petteri Sulonen
Forum Pro
Rinus wrote:
[snip]
We could make a test: two sets of pictures, one shot in TIFF, one in JPG High, both post-processed with identical actions, and re-saved as JPG, quality 10, and printed at 8 x 10. I will bet that neither you nor anyone else will be able to tell the difference without a loupe.
Petteri
--
http://www.seittipaja.fi/index/
[snip]
Hm. I can't really parse this. The fact is that JPG at low compression will create a very small amount of artifacts, whether it's done in-camera or out of camera. A low-compression JPG from the camera is certainly not "doomed"; you're going to have to do something extremely drastic in order to have the artifacts show up; they certainly won't in normal sharpening / levels and curves tweaking operations.
We could make a test: two sets of pictures, one shot in TIFF, one in JPG High, both post-processed with identical actions, and re-saved as JPG, quality 10, and printed at 8 x 10. I will bet that neither you nor anyone else will be able to tell the difference without a loupe.
Petteri
--
http://www.seittipaja.fi/index/
R
Rinus Borgsteede
Guest
Be my guest but I will not bet on that simplification. There are all sorts of reasons why digital files deteriorate and this is one. The second is the problem with the 16 bit / 8 bit conversion. They all contribute to losses that are subtle but accumulative. I do not think that there are too many losses but to make a point, I shoot products for brochures. They have sharply defined edges against a white backdrop. When shooting Jpeg they have the jaggies when shooting Tiffs they still have jaggies but are better. When I shoot RAW, I have a silky smooth edge. I know it is not enough to ruin everyday images but it will kill a good nature shot with jaggy edges on all the sharply defined leafs.
Petteri Sulonen
Forum Pro
theswede #100093
Senior Member
Doubtful, but as you say, might .
JPEG2000 makes zero difference in low compression. Nada. Zilch. None. In high compression it leaves different artefacts than "old school" JPEG, which for some kinds of pictures are better. However, it's not universally better; some pictures look better compressed with JPEG.
Besides, the licensing terms for JPEG2000 are atrocious, designed to make the user pay to watch legally owned pictures. The minimal quality improvement at high compression levels is not worth that sacrifice; any wavelet based compression format will offer the same small improvement over JPEG.
--
Jesper
Keyboard shortcuts
- f
- Forum