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06/27/2005 12:01:35 PM · #1 |
Hi
I'm just starting off with my new 20D and I want to get my images up to around 50MB. I'm capturing my images as JPGs, saving them as TIFFs using Photoshop Elements 2 and upsizing using John Miranda's Resize Pro (by around 150% to get the required file size). However image quality is not great (poor image details and not sharp) after this - any ideas where I'm going wrong?
Thank you!!
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06/27/2005 12:05:50 PM · #2 |
Resizing will always affect detail. Applying USM once the resize process may help however I think you'd be better off shooting in RAW to avoid any compression from the get go. Assuming you have the software to do the conversion.
Raw Shooter Essentials is free.
Message edited by author 2005-06-27 12:06:54.
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06/27/2005 01:35:42 PM · #3 |
Originally posted by globalcat:
using John Miranda's Resize Pro (by around 150% to get the required file size). ... |
John Miranda? Must be Fred's smarter brother.
Welcome to dpc Greg.
Why are you going to such large files? If it is to make large prints you should keep in mind that the larger the print the greater the viewing distance, so some minor defects will go unnoticed. I haven't used it but the generally reccommended program for big increases in file size is Genuine Fractals.
RawShooter | essentials 2005 is fairly new but has already been updated a few times. It's been pretty well received and they say the basic module will remain free.
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06/27/2005 01:43:18 PM · #4 |
at 8.2MP I can't see how a JPG could become a 50MB file without serious loss of quality.
the "safest" way to grow an image is the 110% interpolation way....long but fairly effective HOWEVER there is a limit, rarely more than 4 x110%.
The trick is to open the canvas, than make it 110% bigger, and again and again.. |
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06/27/2005 01:59:42 PM · #5 |
I've recently been taking images from the D70 (only 6 MEG compared to the 20D's 8 MEG) that were shot as JPEGs (in the days before I moved mostly to RAW).
My first action is to resave as TIFFS so that no further degradation comes from the lossy JPEG compression.
I then do all my processing on the image itself (excluding sharpening) and then resize using Genuine Fractals all the way up to 48 MEG (which is roughly 200% increase).
These images have been accepted by Alamy so I assume the quality has been deemed to be acceptable.
I have not sharpened them as this is something best applied depending on final output which is why Alamy require unsharpened images.
I am soon going to start processing RAW images taken on the 20D in December which I'll then also be resizing by 200% or so.
I'll let you know how I get on with those.
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06/27/2005 02:19:18 PM · #6 |
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06/27/2005 02:53:50 PM · #7 |
Visual comparison of various interpolation algorithms (FYI... there is no difference between Genuine Fractals 3.0, 3.5 and 4.0 in terms of the actual interpolation. 3.5 added 16 bit support and 4.0 improved workflow. Also "Stair Interpolation" is the term used to increase resolution in small increments, like 10% at a time.)
Message edited by author 2005-06-27 14:55:03.
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06/27/2005 04:05:47 PM · #8 |
Can't use Genuine Fractals here.... won't work with CS2 at this time! What else do you have in mind? How about PHOTOZOOM PRO?
Message edited by author 2005-06-27 17:05:51.
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06/27/2005 08:13:35 PM · #9 |
Anyone have other suggestions? This thread just seemed to die!
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06/27/2005 08:35:10 PM · #10 |
Why do you need a 50mb image file? Printing a billboard or on a bus or something?
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06/27/2005 08:50:47 PM · #11 |
Why is the large file size needed? good question...
Message edited by author 2005-06-27 20:56:26.
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06/28/2005 07:25:24 AM · #12 |
| I found that the easiest way to get 50MB files was to buy a 1DsMkII.... |
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06/28/2005 09:08:14 AM · #13 |
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06/28/2005 09:25:45 AM · #14 |
Originally posted by gusto:
Why is the large file size needed? good question... |
Because some stock agencies (Alamy) require large tiffs (48MB min, I think). For the Digital Rebel, this means increasing the image by about 170%.
-Chad |
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06/28/2005 09:32:48 AM · #15 |
Originally posted by cpurser:
Originally posted by gusto:
Why is the large file size needed? good question... |
Because some stock agencies (Alamy) require large tiffs (48MB min, I think). For the Digital Rebel, this means increasing the image by about 170%.
-Chad |
I believe they ask for such large files partially to keep to using professional equipment using photographers.
If you had a high-end Canon, like the 1DsMkII, or a Fastback for a Wide-Format camera, you would have no problem with getting images that size.
Of course, that means spending a metric ton of cash, which amatuers aren't likely to do.
If you shoot in RAW, then you could get images closer to that 50MB size, but you won't get up that high with the camera you have. |
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06/28/2005 09:37:49 AM · #16 |
| I don't know if this is a dumb answer cos I don't know what some of the mentioned programs do, but I read in Scott Kelby's book on Photoshop that if you increased the file by only 10% each time, then repeat until you end up with the desired file size, you get hardly any loss of image quality. I have never tried it myself tho. |
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06/28/2005 09:53:22 AM · #17 |
Originally posted by JulieG:
I don't know if this is a dumb answer cos I don't know what some of the mentioned programs do, but I read in Scott Kelby's book on Photoshop that if you increased the file by only 10% each time, then repeat until you end up with the desired file size, you get hardly any loss of image quality. I have never tried it myself tho. |
well this is exactly the method I am reffering to and it's the method used by all the commercial studios I know of. in the end there is a limit to interpolation of course...I think that 4 or 5 times 10% is pretty much the max. |
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06/28/2005 09:56:32 AM · #18 |
The idea behind a 50mb is obviously to get a large printable image and a high pixel count for cropping purposes.
I really can't imaging what a detailed shot at 6mp will look like once up to 170%... I can't imagine it being very detailed and therefore almost impossible to crop in. |
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06/28/2005 10:02:39 AM · #19 |
I have been using Extensis Pixel Smart Scale.
works like a charm! |
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06/28/2005 10:05:18 AM · #20 |
Originally posted by Gil P:
The idea behind a 50mb is obviously to get a large printable image and a high pixel count for cropping purposes.
I really can't imaging what a detailed shot at 6mp will look like once up to 170%... I can't imagine it being very detailed and therefore almost impossible to crop in. |
If you like I can show you over a 100MB file that looks good. It shows
and enhances my every flaw. For example, I should have used a tripod! |
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06/28/2005 11:24:55 AM · #21 |
Originally posted by superdave_909:
Originally posted by Gil P:
The idea behind a 50mb is obviously to get a large printable image and a high pixel count for cropping purposes.
I really can't imaging what a detailed shot at 6mp will look like once up to 170%... I can't imagine it being very detailed and therefore almost impossible to crop in. |
If you like I can show you over a 100MB file that looks good. It shows
and enhances my every flaw. For example, I should have used a tripod! |
well exactly...I don't think that a stock agency wants to promote images from which the flaws are aparent!! there is a difference between a 6mp camera and a 22mp camera... and it's not just the price. |
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06/28/2005 12:24:58 PM · #22 |
That alamy will be the death of us!
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06/28/2005 01:01:20 PM · #23 |
If the file size is the important factor and neglects pixel count then there is something seriously wrong with the specification. There should also be a requirement for pixel density and bit depth, ie. 8, 12, or 16 bit accuracy. The 20d produces an 8 megapixel image which should easily print a 20" X 30" poster for viewing at a distance of 5 feet or so. You can increase the image file size by 25% just by converting the image to CYMK. TIF files are pretty large by comparison to jpeg, so shoot in RAW or TIF format and save as a 16 bit tif file. I think you can probably get a significant increase in file size with a full frame image saved as CYMK, 16 bit, TIF format.
Just checked using a .cr2 file from a Rebel XT, saved as 16 bit TIF yielded a 45.5 megabyte file. Converting to CYMK should easily put the unaltered (pixel count at 8 megapixels) file well over 50 megabytes.
Message edited by author 2005-06-28 13:09:15.
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06/28/2005 01:23:40 PM · #24 |
Originally posted by ElGordo:
If the file size is the important factor and neglects pixel count then there is something seriously wrong with the specification. There should also be a requirement for pixel density and bit depth, ie. 8, 12, or 16 bit accuracy. The 20d produces an 8 megapixel image which should easily print a 20" X 30" poster for viewing at a distance of 5 feet or so. You can increase the image file size by 25% just by converting the image to CYMK. TIF files are pretty large by comparison to jpeg, so shoot in RAW or TIF format and save as a 16 bit tif file. I think you can probably get a significant increase in file size with a full frame image saved as CYMK, 16 bit, TIF format.
Just checked using a .cr2 file from a Rebel XT, saved as 16 bit TIF yielded a 45.5 megabyte file. Converting to CYMK should easily put the unaltered (pixel count at 8 megapixels) file well over 50 megabytes. |
Alamy asks for 8 bit depth and RGB format. Therefore a 6 megapixel cam produces about a 17-18 mb tiff file out of camera.
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06/28/2005 01:48:50 PM · #25 |
I swear they just have some sort of deal with the CDR manufacturers, they make sure you send huge files and send them on cd so you can only get a dozen on each disc... wonder what they do with all the cds they get :O
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