I just received my Valoi easy35 kit to replace my EFH Kit in hopes of getting rid of some issues. My main issue before was, that I got bright edges around where the border starts - that is in the inverted image meaning some kind of darkening of the edges in the negative scan before conversion, which only becomes apparent during the conversion because the contrast gets boosted so much, especially with thinner/ underexposed negatives. Now I realise that it was not the scanning kit but maybe a vignette from the lens?! Using a nikkor F mount 55 3.5 macro lens with extension tube.
If anyone has more insight into this issue I’d be super happy to hear it
I tried flat field Correction but my “flat-field calibration frame” looks pretty even overall and lightroom doesn’t recognize it, it just says: The first or the last of the photo selection must be a flat-field calibration frame. when it is indeed selected as the first.
I have yhe easy35 and I scann with canon macro 100mm ef. I get also this white vigneting specially on dark images that have only a small white point or not a pure white point in the whole image.
I apply some extra white vigneting correction on the profile lens correction and some times makes the trick, but others is not enough.
I still didnt find a bullet proof work flow about this. But I think is a problem between LR lens profile calibration, the natural vigneting of the lens and the NLP algorithm analysing the luminosity of the picture.
Would be great to have an option in NLP to deactivate lens profile or to manually change the vigneting correction.
I found the problem - it has to do with the film holder, just the same as it was the problem with my EFH. Basically both EFH and easy35 have the light source too far away from the negative and in combination with the diffuser, the edges of the frame get less light from the light source as parts of the frame that are closer to the center. This only becomes apparent in thin negatives, but still, for the money of the easy35 it is a bit of a bummer.
My solution is now: cinestill cs-lite and on top my EFH, but with the negative holder at the very bottom position (maybe 1cm away from the actual light panel). I am also masking out all the areas that are not needed to create a uniform light source on the cs-lite. incredible difference!! Got the tip from a guy Will, in the facebook group “scanning film with a digital camera” If I remember the name correctly.
In essence, EFH is a flawed product without modification, if you want to get optimal results with a capable light source like the cs-lite. If you don’t have a light source like that, you need the diffuser, and then it kind of makes sense to design EFH like that. But it is marketed as something optimal… whatever.
Meanwhile easy35 is very very user friendly but is flawed by design and you cannot modify it - They need to make a V2 that addresses this “vignetting” issue. I sent mine back as I don’t need anymore anyways with my modded EFH!
just a quick convert of the image from a above with the negative holder right above the light source without a diffuser. Please ignore the dust spots, that’s my bad.
I have the same problem with easy 35 and Cs-Lite. What I do is to convert the images using only the center of the photo and after I apply some positive vignetting in Lightroom’s optic correction panel. That does the trick
Interesting. I haven’t had that issue with my EFH. I use mine with a Viltrox L-116t LED panel, separated by a half inch of black “railroad board” (black foam core board). The feet of the EFH sit in holes drilled in the foam. There is a cutout to let the light pass into the EFH diffuser. The LED panel is Velcro’d onto the bottom of the railroad board, which is raised off the copy board by three strips of 1"x2" (nominal) lumber. I mask off all stray light and use a black velcro shroud to keep stray light reflections out of my macro lens. One thing that is CRITICAL is lens and sensor cleanliness. Dust and fingerprints or pollutant haze on the lens surfaces or sensor IR/UV glass will create flare.
Another critical element is that the film must be held as firmly as possible in the EFH, so get those nylon screws snug! The latest version of the EFH does a better job of holding the film than earlier versions, so if you haven’t done the upgrade, it is worth it.
Finally, use a moderate aperture for your film format. I recommend f/5.6 on Micro 4/3, and f/8 on APS-C and full frame.
Had a look at your correction frame with “Digital Color Meter”, an app that comes with macOS:
The frame has a falloff that ± corresponds to the bright edges in your first sample screen.
The falloff seems to not be important enough for Lightroom to recognise it when you tried flat field correction…which is a pity because one would assume that FFC can also correct minute differences.
According to what I found in respect of FFC, I assume that you took the reference frame with the same settings as your negative(s). Changing something (distance, f-stop and whatnot) might make Lightroom reject the reference frame based on metadata…but that is my guess only, but it might be worth exploring.
As for the illumination of the negative: Intensity drops inversely proportional to the distance between the light source and the object. This also takes a toll with diffused light, specially when two diffusers are used. This means that the first diffuser (as seen from the light source) must be bigger than the second diffuser, which should be bigger than the negative (unless the distance to it is zero).
Diffusing the light helps to even illumination of the negative, but the diffusers need to be big enough in relation to their distance and size of the illuminated object or negative.
Here’s how light levels look on a model panel with 15 LEDs in a row:
(made with “Grapher”, a utility that comes with macOS)
Note how neighbouring lights add to overall brightness. While the central light outputs the standard “1” (in arbitrary units) like all others, the overall central brightness is almost 3 times higher. Better evenness can be attained by moving the diffuser further away from the lights, see real world example:
Left: Diffuser way too close to the LEDs. Right: Better, but still too close.