Most of my scans have what looks like light bleeding in from the edges. Obviously it’s an inversion so I figure it’s either underexposure/vignetting or some kind of reflection…
1/60th - 1/125th (Exposing just to the right of the histogram)
Moving the lens further away from the negative seems to help but it doesn’t seem like a great solution since I lose so much resolution. It also becomes more difficult to focus on the grain of the film.
The only thing I didn’t try is using a lens hood (I bought mine for cheap on ebay and it didn’t come with one)
Wondering if I need to invest in a better lens or if anyone has a more economical solution. Thanks!
What do you get when you take a photo (through your equipment) of an evenly lit background with different apertures?
The lens you use is a full frame lens used on an aps-c sensor. Vignetting should be less of a problem, nevertheless, a test as mentioned above might help to track down the issue.
I am wondering if your light source, or possibly ambient room light might be inducing flair or reflections?
A. Do you use a mask to block off all light from your light source except that which pases through the film?
B. Do you work in a darkened room or othewise take steps to be sure no ambient light sources are reflected from your film and no light can strike your camera lens?
A lens hood will not help in the case of A, but might help if B.
I assume you have eliminated the possiblilty that the streaks are actually present on the film, as they would be if caused by light leaks in your film camera.
EDIT: Oops, I see some of my suggestions have already been covered on the other thread. But looking at the examples on that link reinforces my suspicion that an overhead room light may be reflecting off of the surface of your film.
@Digitizer I’ll try that and report back. Thanks for the suggestion.
I did try taking a shot of a blank strip of negative. I didn’t notice any vignetting or uneven backlighting of the lightpad.
A. Yeah, I taped over the rest of the lightpad with black electrical tape, only leaving a window big enough for the negative.
B. I work in a mostly dark room. There’s a small amount of ambient light that seeps through between the black-out curtains I have on my window. I can’t imagine it’s enough to cause a reflection though.
I wonder if the lightpad is giving off enough light to illuminate objects around my desk (maybe even my shirt?) in turn causing reflections.
I was thinking about creating some sort of tube or box with non-reflective material to place between the negative and the lens… Good idea or bad idea?
I know it’s not a light leak in my camera as I had the same roll scanned by a lab for comparison.
When working in a room with windows during the daytime, I use an empty oatmeal box painted flat black inside to shield the negative and lens, but in a darkened room I don’t think it’s necessary.
Considering you have eliminated other sources of light and reflections - and further supported by the fact that moving the camera away from the negative seems to help - makes me suspect the camera or lens itself may be causing a reflection (?)
Is there any chrome trim on the front of the camera or lens?
I assume you would not have a “UV” filter on the front of your lens for this application, but if so, that would be a flat surface that might reflect light back down on the negative.
This might be the second step. My first step is to take your camera including lens, adapters etc. and point it at a white wall that is evenly light by daylight. Make sure you don’t cast a shadow, however faint… If this leaves no vignetting, the source might be the remaining setup - or the originals themselves. What does your lab scan give you?
This is the result of uneven light distribution across the negative. You can manually improve the results working with the Vignetting sliders under the Lens Corrections panel in Lightroom, but the best results are obtined using Flat Field Correction which is fairly easy to implement as part of the digitizing process. I posted some analysis on my blog. https://www.cuchara.photography/blog/2019/5/better-negative-scans-using-flat-field-correction-in-lightroom
Wow this is the first I’m hearing of Flat Field Correction. Seems like a good option if it’s not possible to get even lighting/exposure otherwise. Your blog post is very informative! I’ll try this today and see how it goes. Thanks!
As I understand it, the negative carrier must be exactly the size of the negative itself, then the extra light from the lightpad will not illuminate the frame. With Skier negative holders I can easily cover empty areas of light for 6x7, 6x8 & 6x9 films, but with a 6x6 frame size, it is not possible because the two parts of the negative holder rest on each other.
I’ve been trying to get similar effects like you do, but did not get them. I was shooting in a daylight room (no direct sunlight) in a corner besides a window. Backlight was a Kaiser device and exposure was 0.5s, f/8 at 100 ISO, 120 film fixed in a lomo digitaliza device. Ambient light was >5 stops below exposure.
Empty areas do matter for white balance, but did not seem to have further influence.
Hmm weird. That sounds like my setup minus the day-lit room (and I’m using an artograph lightpad). Are you using a modern macro lens?
I took a few shots of a white surface lit by daylight like you suggested. I bumped up the contrast and lowered the exposure in LR. Seems like there’s some pretty noticeable vignetting. Results below –
I played around with vignette correction / Flat Field Correction like @jnstovall suggested and they’re creative solutions but ideally I’d like a clean scan/shot straight from the camera.
The shots show a pattern each that might be your object’s rather than your lens’s. If the pattern were caused by the lens, you’d have to stick to flatfield correction.
Tested 2 first generation Canon 100mm macros and found that one was sharpest at F4.5 and second copy has same sharpness around F5.0-F9.0. So I’d say it’s no point to trust just reviews as there is difference from copy-to-copy.
It doesn’t matter if the problem is just caused by the lens, or if it is the lighting in the room, or whatever. Flat field correction will eliminate the problem in the digitized negatives. It is very easy to capture a flat field frame before the first film frame, then apply that correction to all frames digitized in that one session. Just start capturing a blank frame at the start or end of each digitizing session to eliminate any artifacts from uneven lighting or lens issues.
Does the Flat Field Correction frame need to be totally blurred / out of focus? My first test was only slightly out of focus with the black mask still distinguishable and lightroom wasn’t recognizing it as an FFC frame.
