Jay, if you ask Lightroom to interpolate to increase the size of the image, that'll add pixels and data and increase the file size. So if your 8-bit TIFF is at 300 ppi and approximately 10x13, for example, you can keep the ppi at 300 and keep upsizing the image in 5 or 10 percent increments until the file size reaches 50Mb.
If you save the 65Mb 16-bitt TIFF using compression, you might hit the 50 Mb mark.
But why is it important to have a 50Mb file size? That seems like the tail wagging the dog to me. I size the image to what I want and let the number of Mb take care of itself.
Each pixel has a red, green, and blue component 8 bits long in 8 bit mode. That's 3 bytes per pixel (1 R, 1 G, 1 B). 3x12 = 36MB from a 12MP image with no TIF compression.
If you want 48-55MB files you need a larger source file (greater than 12MP), more than 8 bit depth, or fake pixel content from upsizing the image.
Like the other's said, you need to interpolate to create more pixels to increase the pixel dimensions to your specified size. Not sure about Lightroom, but in photoshop the image size dialog will give you the pixel dimensions so you don't need to troubleshoot 'the long way' to figure out how large to go to get that size. Resizing to ~5100 pixels in the longest dimension at 4x6 ratio will give you about a 49+ file.
In Lightroom you can upsize when you export the file.
1) File, Export.
2) Choose your Export Location & File Naming.
3) File Settings, Format = TIFF / Compression = None
4) Image Settings, Color Space = AdobeRGB / Bit Depth =8bits / Resolution = 300 ppi
5) Check the Resize to Fit box.
6) select from the drop down boxes Long Edge / Pixels then try 4000 in the other box
7) Check the image size and redo step 6 to fit your needs
I have a stock agency interested in some of my photos, and that's what they requested.
Posted by David Bostedo on July 30, 2008 at 10:20 PM
Hey Jay - I kind of figured that was the reason when I first saw your post, since I've heard of that before for certain publications. It seems like there must be some misunderstanding of digital files that they request things this way. It seems to make a heck of a lot more sense to specify a pixel count or dimensions (along with file type and compression perhaps), than a blind file size.
Are there a lot of places around that still ask for digital files of a certain number of megabytes? I'd think that would be going away most places...
I've encountered uneven levels of digital photo manipulation expertise at some of the magazines I've dealt with. Surprising, too. You'd think they'd ALL know what they are doing, but it's just not so. When I get an inquiry these days about an image a mag wants to publish, I never know quite what to expect from their photo technicians. Could be I'll get someone who could have written the code for CS3, but I might just as well get someone who says: Interpolation? What's that?
Discussion
10 repliesI'm trying to convert an uncropped RAW file from a 12mp camera into an 8-bit TIFF with a file size of around 48-55mb.
Using Lightroom, I'm getting 8-bit TIFFs around 24-28mb. If I go up to 16-bit TIFFs, I get a file size of 65+mb.
I'm told by others that I should be able to get 8-bit TIFFs the size I want, but so far, no luck.
Am I missing something? Any feedback would be appreciated. Thanks in advance.
If you save the 65Mb 16-bitt TIFF using compression, you might hit the 50 Mb mark.
But why is it important to have a 50Mb file size? That seems like the tail wagging the dog to me. I size the image to what I want and let the number of Mb take care of itself.
If you want 48-55MB files you need a larger source file (greater than 12MP), more than 8 bit depth, or fake pixel content from upsizing the image.
1) File, Export.
2) Choose your Export Location & File Naming.
3) File Settings, Format = TIFF / Compression = None
4) Image Settings, Color Space = AdobeRGB / Bit Depth =8bits / Resolution = 300 ppi
5) Check the Resize to Fit box.
6) select from the drop down boxes Long Edge / Pixels then try 4000 in the other box
7) Check the image size and redo step 6 to fit your needs
Hope this helps.
Marshall
Are there a lot of places around that still ask for digital files of a certain number of megabytes? I'd think that would be going away most places...
I've encountered uneven levels of digital photo manipulation expertise at some of the magazines I've dealt with. Surprising, too. You'd think they'd ALL know what they are doing, but it's just not so. When I get an inquiry these days about an image a mag wants to publish, I never know quite what to expect from their photo technicians. Could be I'll get someone who could have written the code for CS3, but I might just as well get someone who says: Interpolation? What's that?