Scanning slides

[davidmj]

I bought a film scanner to scan my 35mm transparencies. It goes up 7200 dpi but I have been scanning at 3600 dpi with 48 bit color saving to Photoshop PSD files. The file sizes are around 90 MB.
The problem is if I want a service to make a print from one of my digital files, the file size cannot be larger than 50 MB. If I take a 90 MB file, resize it in Photoshop to 11 by 9.5 inches and save it as a TIFF the file size is 70 MB. To get a good print, do I have to scan to lower resolution with a lower bit color to get a smaller file size or will a 8 bit per channel maximum quality JPEG file that is 7.8 MB print just as well?

 

[Ysarex]

Yikes! No way should an an 11 x 9.5 TIFF file be 70 mb if it's prepped for printing. Even if the TIFF was 16 bits that's still more resolution in an 11 x 9.5 file than you need to print. An 8 bit uncompressed TIFF at 300 ppi and 11 x 9.5 inches is only 27 mb and that will compress losslessly to less. A 16 bit TIFF at 300 ppi and 11 x 9.5 inches is only 52 mb with lossless compression.

And the JPEG will print just peachy. Just make sure the JPEG compression is the final step and don't make changes after that.

Joe

 

[Light Guru]

Why are you scanning to photoshop files?

Scan to TIFF files and send JPEGs off to be printed.

Sent from my iPhone using Tapatalk

 

[davidmj]

Yikes! No way should an an 11 x 9.5 TIFF file be 70 mb if it's prepped for printing. Even if the TIFF was 16 bits that's still more resolution in an 11 x 9.5 file than you need to print. An 8 bit uncompressed TIFF at 300 ppi and 11 x 9.5 inches is only 27 mb and that will compress losslessly to less. A 16 bit TIFF at 300 ppi and 11 x 9.5 inches is only 52 mb with lossless compression.

And the JPEG will print just peachy. Just make sure the JPEG compression is the final step and don't make changes after that.

Joe

Thanks - I made the mode 8 bits per channel and saved it as a TIFF and the file size is 35 MB. So 8 bits per channel will do just fine for a print - correct?

 

[Ysarex]

Yikes! No way should an an 11 x 9.5 TIFF file be 70 mb if it's prepped for printing. Even if the TIFF was 16 bits that's still more resolution in an 11 x 9.5 file than you need to print. An 8 bit uncompressed TIFF at 300 ppi and 11 x 9.5 inches is only 27 mb and that will compress losslessly to less. A 16 bit TIFF at 300 ppi and 11 x 9.5 inches is only 52 mb with lossless compression.

And the JPEG will print just peachy. Just make sure the JPEG compression is the final step and don't make changes after that.

Joe

Thanks - I made the mode 8 bits per channel and saved it as a TIFF and the file size is 35 MB. So 8 bits per channel will do just fine for a print - correct?

Yes 8 bit will do the job for print -- an 8 bit JPEG will serve well and solve your size problem. You could also reduce your scan resolution to reduce file size. Are you scanning ISO 25 Kodachromes? I can't think of anything else that would contain sufficient information to warrant a 3600 ppi scan. Assuming you have data in your slides that is fully recorded at 2800 ppi. If you scan then at 3600 ppi you get 2800 ppi worth of data and 800 ppi of nothing. As you approach 3000 ppi you pretty much hit the point of diminishing return on nearly all 35mm film stock -- there's nothing more there to scan.

Joe

 

[dennybeall]

And besides that when you scan at 7200dpi the scanner makes this annoying whirring sound for a long time as it scans...................

 

[Derrel]

And besides that when you scan at 7200dpi the scanner makes this annoying whirring sound for a long time as it scans...................

This gives plenty of time to make a sandwich and put the sandwich fixins back in the fridge....or to go out and get the mail, sort through the junk mail and round file it, or to peruse the TV Guide listings, or to look thru the kitchen for what to make for dinner, etc,.etc.. Uber-high bit depth scanning has its advantages in allowing multi-tasking.

 

[table1349]

And besides that when you scan at 7200dpi the scanner makes this annoying whirring sound for a long time as it scans...................

If you put little sneakers on them the whirring sound goes away.