Combine 2 .dng files into one file in Bridge???

[richk34388274]

I'm using an old Canon scanner to make digital contact sheets of my b&w negs. This particular scanner has a negative filmstrip holder that lets me scan 5 strips at a time.

I sometimes have 6 strips to scan however, and would like to merge 2 scans into one to keep it all in one file.

The scanner software is creating DNG format files for me.

Can I merge 2 DNG files in Adobe Bridge and create a "new" file with the 2 scans?

Or do I just open up the 2 files in Photoshop and paste them togethetr to create one new file.

If I go the Photoshop route what format would I save this new file as? PSD, tif, jpg or another?

[gary_sc · Accepted solution]

That's nice that the Canon software lets you take DNG images, interesting.

But to your question, no. DNG images cannot be changed or altered. Only the interpretation of the images can be affected by such applications as Adobe Camera Raw or Lightroom. To combine them would be to change them.

To do what you want is possible if you save them out as TIF or PSD images but then you lose the ability that DNG provides. 

So yes, your 2nd solution is the way you want to go.

To save them, if you use TIF or PSD you will get the best image. If you save as JPG, you will then get JPG degredation and you do not want that. 

As an aside, Once you make your composit image, any subsequent enhancments should be done with layers. Do not make changes on the original image and save that. Here's why: Let's say you want to get rid of the fire hydrant on your front lawn. So you take your rubber stamp, fix it, save it, and your done. It looks "OK." But later you learn about "Content Aware Fill" and want to see if that will give you a better result. Well, it's too late, you can't test this on that fire hydrant because you saved over that part of the image, you're stuck. The only way to try that now would be to rescan the negative. Bummer.

So when you have original negatives to work with, get the best quality scan you can and save them in a non-distructive format, and never change those pixels.

hope this helps.

[gary_sc]

Oh, I forgot to mention. KEEP those DNG images for the same reason. Do not toss them.

In fact, there's no real reason to HAVE to save them as doubled. You'll be better off in the long run to just have the two strips. 

[richk34388274]

Thanks for the explanations.

Makes sense and sorta what I thought would be the case.

BTW

I use VueScan scanner software. It lets me save scans in dng formats.

Their software works with tons of scanners, letting them live on once the manufacturer of an older scanner abandons it or its software.

[gary_sc]

Hi Richk,

Ahh, OK, thanks. Yes, Vuescan software is good software and that explains a lot about your DNG images. I was rather surprised that Canon software would save in DNG format (since their cameras do not, only CR2 format for raw). But Vuescan, yes.

Small favor, if you could please tap the "Correct Answer" option below my answer, it helps flag that if anyone else has this issue, they can go to this thread to find an answer. it helps others.

Take care, stay safe.