60MP scan of 6x6 MF film using 12MP DSLR

[sunnycamera]

I just finished my first roll of MF film (NP160NS) on my Seagul 4A, a 20+ year old camera from my parent,

My first MF stitch-scan attempt, as I have only scanned 135 film in one shot.

crop sensor Pentax 12MP kx camera, vivitar 2x macro tele convertor, 28mm f2.8 lens. set and measured at 1:1 setting.

here is the initial setup and result.

8k x 8k resolution

at 25% crop view

at 50% crop view

as you can see the laptop LCD pixel shown up even in 25% view, so effective 1st attempt is around 15 MP range, and color is a bit off as well.

Next, I will try use a white transparent board to filter out the pixel dots, will update results here later. and use another longer lens for distortion improvement.

 

[sunnycamera]

Here is the update: Oct -03

I have just done another scan of 2nd frame,

Changes in process.
0. turn of all the lights
1. instead of using 1 block of Majong block to lift up, I use 2 stack of Majong block to lift it up from LCD. now the dots are gone,
2. 8kx8k, and using 2x Macro Tele convertor + 50mm f1.2 at f2.8 for better resolution
3. 6 frames stitch, while 14 shots taken.
4. expose a lot more to get dark film area
5. PHotoshop correct setting
-- invert adjustment layer
-- level adjustment layer, use white drop to sample the edge of the film to define max exposure level, then maximum and tune the range in R, G, B level channel to remove color casting
-- layer and mask of each partial scans

here is 30% crop view, 1k resolution

it take 1 hour to get 1 frame done, will get a scanner later for ease.

 

[crispy12]

I had this problem before when I used my Ipad as a lightbox. What you need to do is use two pieces of glass to hold your negative in between and elevate it above the lightsource. This will distance it far enough from the screen such that the pixels will be very OOF and effectively give you a diffusely lit background, especially if you are using a long lens. Alternatively borrow a film holder from a scanner and elevate that but glass is better as the film will be flat. Can see the unevenness in your shot above.

I used a 300mm zoom lens at f8 with the negative about 3cm above the screen and the background pixels were not visible at all.

I've tried using paper, thin cardboard and various types but paper will always show a texture when illuminated. White plastic might work as well but I didn't have it available. Later I got a flatbed scanner, my results were a little bit better with that but 100x more convenient! DSLR method is also not good for 35mm film.

 

[giantcanopy]

Nice project ( though of i believe scanning will be much easier ). The more diffuse the illuminated background for your photos, the less the grain or artefactual gains

Ryan

 

[Nikkornos]

Aiya go invest in a proper light box. The dot dot dot on the screen defeats the effort.
I had always shot using the Nikkor 55mm 3.5 Micro and max out DLSR. But I make sure the film is perpenticular to ground, and camera is horizontal by bubble.
Distance to film checked by the in camera focusing check. Here is one I did and showed before:

I stopped doing this completely by investing in a V700. Its worth it.

 

[sunnycamera]

thanks for the tips, I have done a 2nd frame, and the update is in my 2nd post above,

looks much better, but definitely less efficient than a scanner.

 

[sunnycamera]

just finished my 3rd frame, get a little easier and faster now after into this flow.

8kx7k (because it is the last frame of the stripe, it is hard to get the edge scan from side blocks)

after calculation, 12MP APSC sensor at 1:1 give 4615 ppi (4288 pixel width resolution /0.929134 inch sensor width)

Here is the photoshop layout


Seagul 4A 8k DSLR scan photoshop neg to positive

30% crop view

 

[pinholecam]

Interesting attempt.
I just got 2 macro stages a few weeks back and was planning to do something like this too.

I use a plain A4 paper as bkgnd with 2 bright lamps shining on it as the 'lightbox'
I think it works better than the ipad.

 

[myecholalia]

If you want to pursue this method further, give the PhotoAcute software a shot. What you do is to take 5-7 pictures of your negative/slide, which then get combined by PhotoAcute into one high resolution DNG RAW (!) image which you can then process further. I did not use it for negatives/slides in the past, but when used properly it gives very impressive results.

Regards
Thorsten

 

[crispy12]

If you want to pursue this method further, give the PhotoAcute software a shot. What you do is to take 5-7 pictures of your negative/slide, which then get combined by PhotoAcute into one high resolution DNG RAW (!) image which you can then process further. I did not use it for negatives/slides in the past, but when used properly it gives very impressive results.

Regards
Thorsten

You can do this in photoshop using the photomerge setting. Works very well.

OP, for the side frames you can still rest the film on the edge right at the border. The black border will be uneven but can easily be coloured in again using PS. Takes about 10secs of effort. Hardest part is getting the film flat.

 

[Darcy.Zhou]

Another way is to use a type of acid paper to cover the screen.