DPI

[Jackie Schuknecht]

When opening a file in ACR is it better to set the dpi at 240 0r 300 (@ 16 bit). I have a 7D so I have a lot of pixels to work with and probably wouldn't print on paper larger than 11 x 17. Also since I have only 2G RAM on my computer it is really slow since getting the new camera. I have been using 300 dpi.

[Axel Hildebrandt]

Putting more RAM in your computer would make a big difference.

[Jackie Schuknecht]

I don't think I can Axel (will only take 2), are you saying that 300 dpi is better then? Getting a new computer is not an option for me right now.

[Roy Churchill]

Jackie, the DPI does not effect the file size whatsoever - whether you open it at 100 dpi , 300 dpi or 1000 dpi it does not matter - it is only at print time that DPI is used.

[Axel Hildebrandt]

I don't think I can Axel (will only take 2), are you saying that 300 dpi is better then? Getting a new computer is not an option for me right now.

300 dpi is standard for printing, I save all TIFF files as 16 bit and 300 dpi, but that makes the files rather large, if you just want to process an image for the web, you could go to 72 dpi. If your computer gets too slow, you could save the files as 8 bit.

[Roy Churchill]

300 dpi is standard for printing, I save all TIFF files as 16 bit and 300 dpi, but that makes the files rather large, if you just want to process an image for the web, you could go to 72 dpi. If your computer gets too slow, you could save the files as 8 bit.
Alex, re my post above, surely the dpi does not alter the file size at all be it 72 dpi or 300 dpi.
Obviously a 8 bit will be smaller than a 16 bit but the dpi does not come in to it.

[Axel Hildebrandt]

Alex, re my post above, surely the dpi does not alter the file size at all be it 72 dpi or 300 dpi.
Obviously a 8 bit will be smaller than a 16 bit but the dpi does not come in to it.

Yes, you are right. What I mean is that the 300 dpi only matter if a file is intended for print and the difference in file size depends whether it is saved as 8 or 16 bit. Since newer cameras support 14 bit, I prefer to keep everything at 16 bit before saving for the web to keep as much image information as possible.

[Jackie Schuknecht]

I don't think my brain and hand are connected yet this morning. I meant to say PPI when opening in ACR. Is it better to have 240 PPI or 300 PPI. I knew I would get it screwed up. My apologies. I do know about the Dots per inch for printing. (Sorry)

[Axel Hildebrandt]

I don't think my brain and hand are connected yet this morning. I meant to say PPI when opening in ACR. Is it better to have 240 PPI or 300 PPI. I knew I would get it screwed up. My apologies. I do know about the Dots per inch for printing. (Sorry)

I have it at 300.

[Roy Churchill]

I don't think my brain and hand are connected yet this morning. I meant to say PPI when opening in ACR. Is it better to have 240 PPI or 300 PPI. I knew I would get it screwed up. My apologies. I do know about the Dots per inch for printing. (Sorry)
Basically the same thing as far as you are concerned Jackie - you can set whatever ppi you like it will not alter the file size.

[Roger Clark]

Jackie,
Roy has it right. The ppi (or dpi) is just a parameter to tell how far apart to print the pixels when printing. It does not change file size regardless of what it is set to in your camera or in the raw converter. It does matter if you change it in your photo editor when interpolating images. For example, in photoshop's image size, changing the ppi from 240 to 300 will increase the file size if the resample image box is checked.

Roger

[Jackie Schuknecht]

Thanks Roger, Roy sent a PM, and explained it all to me. Basically 300 ppi is for printing larger pics. Just taxing my computer's RAM with some of the file sizes and plug-ins like Frac, and Dynamic Auto-Painter. With only 2 G of RAM I am maxed out. (I need a new computer)