Without knowing your set up it’s difficult to comment. As you probably know flat field photography requires that the sensor and the subject plane are exactly parallel and that the subject (the film) is truly flat. I would first check that these criteria are fulfilled. Keeping film truly flat is more difficult than many think.
That said, the Sony Macro 90mm G OSS is not renowned for its edge sharpness. If you combine that with a bit of barrel distortion and a touch of film curl, you could be looking at the answer to your question.
Your scans are of lower contrast than the lab’s scans which may point a finger at your light source being more diffuse. That is not an uncommon finding and can overcome by experimenting with the distance from your light source to the diffuser.i.e adjusting the degree of collimation.
Although it’s a bit of a hobby horse of mine, a far better option as far as lens choice is concerned would be a scanner lens. These are optimised in every respect (very high resolution, very flat field and near zero chromatic or other distortions) for this job (and no other) while macro lenses simply are not.
I’m using 99CRI 5x7 Light Source Pro from Negative Supply, as well as the rest of the setup, all Negative Supply. Do you think their setup might be the issue?
I understand that parallel plane might be the issue, however to eliminate that in my study, I focused and evaluated on just a really small patch of the image at the center, instead of the whole image. I used a mirror and viewfinder grid to align the camera, so it should be good enough that there shouldn’t be any varying focus at F/8 when focused and evaluated on a tiny 12x patch of the image.
I know you’ve been an advocate for scanner lenses, and I’ve looked into it per your recommendation. The problem is that I can’t find anywhere that readily sells them (For example your recommended Minolta DiMAGE Elite 5400 Scanner Lens), nor information on how to adapt them to work with my A7R IV. So the lack of information or product supply pretty much made it not an option for me unfortunately.
Your setup looks solid, but I’m not so sure about the lens. I chose Sigma 105mm DG DN over the Sony 90mm G, but your samples look worse than what I would expect especially stopped down.
Have you used the lens outside of digitizing film? Perhaps you’ve got a bad copy?
I agree with ksk - Negative Supply gear is excellent and your set-up looks pretty damn good - which only leaves the lens. You may simply have a rogue copy and as this is definitely not a bad lens, it’s worth having it checked out. I can understand how frustrating it must be as you have clearly done everything by the book to get things right. Kudos to you for that. it’s almost as frustrating for me as I can’t think of anything else that might help!
Scanner lenses are not available ‘over the counter’ but are often to be found on ebay - especially the Minolta and Nikon scanner lenses which come up for sale pretty regularly. You can also pick up a broken scanner sold ‘for parts only’ but make sure the canny seller hasn’t already removed the bit you want!
A multitude of beautifully machined adapters are available from RAFCAMERA https://rafcamera.com and if you describe what camera/lens/magnification you are working with, Rafael will be able to suggest the bits required.
There is also a lot of information on https://www.closeuphotography.com especially with regard to RAF adapters for the Minolta Dimage lens.
That Sony lens is not a good choice for digitizing negatives. It exhibits noticeable field curvature which is noticeable when going 1:1. My results were similar to yours and I returned it. Someone already suggested a much better lens for this: the Sigma 105mm DG DN.
And in terms of color reproduction, your scans are just a tad warmer than the lab’s. Easily correctable and, as it always is with color negative film, subject to personal preference. I wouldn’t mind the warmth.
I don’t know what’s happening here. At least in the center, the 90 Sony should be a match for the lab (and pretty much any other macro lens), your chimney crop near center makes me think there is something wrong.
Culprit? Vibration? Suggestion; rig electronic flash, don’t worry about even illumination or anything but good focus and enough illumination at the center. For example, turn off the Neg Supply light after focusing, and shoot the flash into the light panel. This should diffuse enough for this test. If the result is sharper, then you probably have some vibration.
If you can get sharp in the center, then work on the corners.
This is a mystery. Please let us know what you learn.
It’s hard to say without being there. That said, I think you ought to be getting MUCH better results for that much money!
Hell, I’m using Micro 4/3, a 16 MP camera, a cheap Lumix 30mm f/2.8 Macro at f/5.6 to f/8, and I like my results better than these. I’m using manual fixed exposure and full area multipoint autofocus on every frame. The AF tends to find the sharpest part of the image when there is slight film curl.
I am using a $40 Viltrox L-116t light panel under an Essential Film Holder, which does a grand job of keeping the film FLAT. My copy stand is made out of a dowel rod and some PVC plumbing parts and shelving and super glue. I don’t use a shroud around the front of my lens down to the film holder, either.
But I do turn off the room lights and I make sure everything is level before I start. I use my electronic shutter to avoid all the vibration I can. I use a two second self timer to allow vibrations to dampen. My table is super-sturdy, and rests on rubber on carpet.
Given the setup you have and the equipment, my guess (like some others) is that you got a bad lens. The Sony 90mm macro isn’t a terrible lens but those shots just look worse than they should. If you can return the lens for a new one or exchange it and get something else, that might be the best solution.
Personally, I use a Sony a7iii (it’s only 24mp) and a Sigma 70mm f2.8 lens and my scans are quite good. So, this might just be the lens and not you.
To really avoid vibration, setting the camera for electronic shutter and tethered shooting might be an option. I have my camera tethered to my MacBook Pro and I use TetherTools software to control the camera. You can also use the Sony software but the TetherTools program enables you to send the shots straight into Lightroom without the intermediate step of using a target folder for import. The tethered shooting means you don’t touch the equipment and everything is done electronically.
I tried the Sony 90mm macro lens and returned it. It is obviously not designed as a flat-field copy lens. I am using a Schneider Apo-Digitar 80mm f/5.6 lens which is designed for this purpose and is very good. Unfortunately it is discontinued but they do show-up on the resale market. I believe LinhofStudio in the UK has one. You may also wish to try a Schneider Componon enlarger lens. These lenses were made for flat-field reproduction.
As for the colour and tonality - be sure you are using the latest version of NLP and check the various tone and White Balance settings in the Edit menu to find a combination that comes closest to producing the result you prefer.
I use a A7RII with a Tamron 90mm 2.8 Macro (latest Version for Canon EF with a Sigma Adapter) and I have no problems at all with sharpness. (As far as i know the Sony and the Tamron 90mm Macros are both Tamron lenses. So there shouldn’t be much difference.) The film grain is track sharp from corner to corner (at F8). I have a Kaiser repro stand and i have discovered, that I have to use electronic shutter on the A7RII to get sharper results. The hole construction is very sensitive to vibrations, even with a solid stand. I also use profile correction and chromatic aberration removal in Lightroom (for the tamron lens).
Have you tried to focus manually? I always use autofocus for every scan. But maybe your lens needs a focus calibration?
Another things is, the lab scans look sharpend to me. Maybe even sharpen plus denoise. Try the same in Lightroom and compare again.
Late reply but for posterity: yes I always manual focus, and tried sharpen/denoise in LrC, didn’t look the same. Now retrospectively I suspect that something was wrong with my lens. In either case, I sold the camera/lens system as I didn’t have more time to figure out why at the time.
I also have a Sony A7RIV and Sony 90mm Macro and I’ve been getting really annoying results. I’m getting what looks like yellow discoloration on my borders once converted, possibly meaning they were dark areas on the negative/in the scanning process. For the life of me I can’t figure out the issue. I’m using a full Valoi 360 setup.