Photoshop question

[PeterAit]

I have been creating reproductions of documents that are too wide for my scanner by scanning the left and right portions separately and then stitching the 2 images together in PS. When pasting one image into the other, I use the mouse for rough positioning and the arrow keys for final positioning. My impression is that the keys move the image in steps that are larger than they might be, preventing really precise positioning. Can this be changed? I have looked thru the PS preferences and not found anything. I am using PS CC 2015.

[D Fosse]

If you zoom in close enough, the arrow keys nudge by 1 pixel increments. Can't get smaller steps than that...

Of course the scans may be misaligned by less than a pixel, and then there's no way around resampling. Auto-align will resample if there's enough overlap. If not, you might try to upsample, nudge, and downsample again.

[PeterAit]

If you zoom in close enough, the arrow keys nudge by 1 pixel increments. Can't get smaller steps than that...

Of course the scans may be misaligned by less than a pixel, and then there's no way around resampling. Auto-align will resample if there's enough overlap. If not, you might try to upsample, nudge, and downsample again.

Thanks! I never thought of zooming in.

[howardm]

I was reading that as you zoom in, the actual # of pixels moved decreases (ie. at 200% it's 0.5 pixel) but that may only be
for vector shapes.

[wmchauncey]

Aah...I might simply try to Photomerge the documents.

[PeterAit]

Aah...I might simply try to Photomerge the documents.

I tried that first, using Lightroom's stitching tool, and kept getting an error message.

[Garnick]

I tried that first, using Lightroom's stitching tool, and kept getting an error message.

Have you actually tried this in PS Photomerge.  As I mentioned in the other thread, I scan oversize pieces quite regularly and as long as I have enough overlap of individual scans Photomerge usually does a fine job of stitching them together.  If I have more than 4 scans(6 for instance), which happens frequently, I sometimes have to stitch 3 scans and then another 3 scans, ultimately leaving 2 stitched images to incorporate into the final stitch.  However, as I also mentioned, if you do not have a way of totally flattening the original pieces the scans may have some deviations due to dimensional instability.  Often even Photomerge cannot cope with that scenario.

Gary