Trying my hand at medium format scans today. I was very impressed with the scans I got from 35mm as they outperformed the lab I used (notitsu hs-1800) in my opinion. In color and detail.
However trying out medium format the lab scans just seem to look way sharper or atleast more detailed with grain. Maybe they’re doing some post processing?
My setup:
sony a380 (14.3Mp DSLR) with minolta 50mm macro lens
Add a bit of structure and the camera scan should improve. Look at the twigs in the upper RH corner and see how much you can push structure and sharpness sliders until you get the same coarse appearance.
Your lens is a bit less sharp in the corners though.
I’m shooting at f8 maybe the film is not quite in plane or the lens is less sharp in the corners more likely?
Do you think the scan in lab was over sharpened or over structured? Is there detail they’re adding that way. Also lab is slightly higher res but there’s nothing in it.
645 film grain at 14MP? Not sure if the grain seen in the lab scan is superficial as in oversharpen effect or similar? I can’t see grain at 14MP on my scan just pixelation at zoom which makes me think the lab scan is overgrained/oversharpened.
I really want to see that grain as it looks good and means im hitting the limits of the medium with my setup.
Lenses can have field curvature, which means that even absolutely flat subjects can have unsharp areas. To find out what your lens does, you can focus the center and near a corner. Also flip the negative (shiny side vs matte side) and see if this makes a difference…
If I believe what I see below, my macro lens has some field curvature at the imaging ratio that I use for copying M645 negatives:
It’s impossible to know whether the apparent sharpness difference between those two samples is due to sharpening differences in software or real optical differences due to the lenses and sensors differing between the two scenarios. The lab would be using equipment that is specified for flat-field copy work, whereas the lens on your DSLR, while a macro lens, may not be corrected for flat-field copy work, and this could be an important source of difference. You would need to compare unsharpened samples to know whether the issue is lenses or software. Vibration can also make a big difference to sharpness. If your copy stand sits in a house with water boilers, central heating units or ait-conditioners running, these appliances can send small vibrations through the building which your copy stand picks up and transfers to the camera. Sensor photosites are very tiny, so vibration can cause microscopic motion blur which impairs sharpness. You may need to insulate your copy set-up using felt or Sorbathane pads under the stand.
I also agree that they are likely doing post-processing. If you have both LR and PS, I suggest turning off all sharpening in NLP/LR and to use the Smart Sharpen filter in PS which yields great results. One way to achieve the grain effect you’re talking about is to use the radius slider to find the edges of the film grain as it is expressed in your setup.
Sample from your scan - Remove Gaussian Blur, Amount: 70, Radius: 1.2, Reduce Noise: 5 (to smoothen out some smearing) (edit: looks like the forum host compressed the image but the grain was looking pretty nice. The lab scan also higher contrast which contributes to the perception of sharpness.)
The grain is inherently there and you just have to uncover it. Conversely, you can use a High Pass Filter to find the edges of the image itself and focus on enhancing them.
Another fiddly way to get higher resolution is to merge your MF scans. LR does a good enough job with Photomerge. You can circumvent the curvature problem by using the best parts of your lens and sensor combination. It could be as simple as using only the middle 30% of each frame, staying far away from the four corners.
You might find tests people have done online to find out the best distance and aperture combination to use for your particular one. This can also help you immensely. Sometimes, it’s not so simple as framing things as close as possible.
Just as an aside, try using a 10x loupe on your negatives to understand the structure of the film grain. You can use that as a reference when sharpening if you want to stay true to your negatives.
I don’t know if you’ve ever tried flatbed scanning, but the sharpening required for that method is high. As Nate advises in his scanning guide: “Don’t get hung up on the numbers.”
