Stitching / panorama for medium format scan

Hi all,

Apology if topic is redundant or obsolete in a way, i tried to search the forum and read the FAQ’s too but i might have missed something

However, as the topic stated, my dslr setup is with 65mm nikkor micro, and a fullframe camera, i wanted to scan 6x6 format using EFH neg holder and viltrox 116 source light, and using Lightroom 6 the non cloud version to stitch in panoramic

I shot 2 images in 6x6, my camera set up was aperture priority, so f8, iso64 and shutter varied slightly between frames to get that exposure compensation +1, when stitched the image suffered from allegedly different exposure being the first image, presumably the 1st half being brighter than the 2nd

So i changed the set up, this time all manual, including the shutter speed, and the result is the same as above

What have i missed? Im willing to go through each step as I’m new to this stitch of processing
Should i use the latest LR?

I never have problem with single shot conversion

I’m not clear at what point NLP comes in to your process here. Your first method of using aperture priority for the two shots wasn’t going to work, clearly the camera is going to give different exposures for the two shots unless the image is entirely uniform. It’s nothing to do with the exposure compensation, just that the camera meter is assessing different ‘scenes’, however using the same fixed manual exposure for both shots should work fine. I use LR 6.14 and I’ve never had this problem, is it Lightroom that is giving you this warning about different exposures?

Hi Harry, after stitching in LR, and converted using NLP i notice the difference being half part of the whole (stitched) image is brighter , i havent got the photo here with me so cant show just yet

I used fixed manual exposure and it is the same results… hence wondering if i ever missed a step

Hi Jakontil,

Thanks for explaining, so it is seemingly NLP that is tripping up somehow. I suppose it would be good to know if the stitched negative looks OK in Lightroom before involving NLP but it is a little difficult to see with a negative I suppose, I doubt that it is anything to do with using Lightroom 6 Perpetual though. Hopefully some regular NLP users can help, posting the stitched image could help as well.

Thanks for replying Harry, and at least i can still rely on my LR6 for now as i have no intention to subscribe for desktop version yet

I love to gain the extra pixels on stitching a medium format however, i’d still live with a single shot till someone sheds me some light on where did it go wrong

Yes, stitching for medium format is the way to go. I also rely on LR6, I know we’re missing out on new features but it still seems to do everything I want it to.

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I recommend you check few things that can cause issues with stitching:

  • The light for “scanning” might not be uniform enough
  • Vignetting or falloff of the “scanning” lens

Thank you, will do on my next chance, may be flat field correction?

Maybe use a blank unexposed frame of colour negative in the same format and take two shifted exposures as before. Use a shutter speed about two stops faster than the one used for your actual image to give some density to work with (or adjust to suit). Inspect in Lightroom and maybe whack the contrast right up to simulate the contrast boost when converting in NLP. Obviously you haven’t said if you are moving the light source and negative together or just moving the negative across leaving the light source in place.

Just making sure, did you stitch before convert (advisable if possible), or otherwise have NLP conversion exactly he same/synced? I can imagine the conversion is a bit different between the two halfs if done separately. You already mentioned one half needed more exposure on auto camera.

Hi harry, im using the EFH holder, so light source stay, and just scrolling up the negative, while camera also stayed

Hi mennodv, i stitched before converting to NLP, judging frm the negs i could see a thin difference with close inspection and when converted it becomes more obvious

Thanks, still worth checking with a blank piece of film I would think, and repeating your scan of this frame if you haven’t already. Vignetting and/or uneven illumination could still be a factor but with that panel and that 55mm Micro-Nikkor (or is that 60mm?) it would be surprising to me. People do sometimes report instances of that holder causing ‘shading’ in certain circumstances, apparently caused by the lower mask interrupting the light path around the edges. If you did happen to be getting shading at the edges then this coulld explain why Lightroom thinks there is an exposure problem. This wouldn’t happen if the holder and panel were moved together but of course I’m not suggesting that you shoulld have to do this, the EFH has been designed so that you can easily slide strips of film through it.

Based on my experience with stitching negatives I think your procedure is broadly correct insofar as you are letting LR stitch the negatives before you bring the stitched result into NLP. That should work. The one thing you didn’t mention which may be worth checking is whether you have (1) triggered the gray balance and eliminated the borders for each exposure before stitching, and (2) turned off any automatic exposure adjustment features in the stitching function before you command the stitch.

As a general comment on your approach to Lightroom, if you can manage the ten bucks per month, I highly recommend moving on to the subscription plan and keeping your Lightroom Classic application up to date. Apart from the myriad of new, very useful features introduced in recent versions, Adobe has been making steady under-the-hood improvements of standing tools which have vastly improved technical performance and results. I have no connection to Adobe, but am saying this simply because I have noticed it so prominently in my own work. It could be that you will get better results with an up-dated version of LR.