I’m scanning my films with my camera and I started noticing few problems, even more visible when my films are underexposed like in my last roll.
Here an example, shot on 120mm Portra 160.
You can see tons of little lights circles, and even worse there’s the “shadow” of the lens in the middle
Sony 90mm F 2.8 G OSS Macro Lens + lens hood / No lens filter on
Bubble level for leveling camera on copy stand
> I close my curtains, I use an homemade construction paper to mask all the light (see photo)
Clearly, there is a problem with light or with my lens.
I tried to scan with an other lens, a Sony 35mm 1.4 and all my lights problems disappear.
But it’s not a satisfying option since the scans are way less sharp than those with my 90mm macro lens.
My question is : does it already happened to someone ? Is my macro lens shitty ? (I’m thinking about changing it for a 105mm Sigma lens) or am I doing something wrong ?
Thanks for your responses ! Have a nice day,
Élise
(PS : sorry if I made some vocabulary mistakes, I’m not a native english-speaker)
For me it would be helpful if you could show a picture of your setup with the cardboard light tunnel in place, first with the 90mm and also with the 35mm (or did you even use it then, you would need to have been much closer?). Then if you have a blank unexposed frame of film try photographing that so that you get a mid tone, histogram in the centre as it were. That way the inconsistencies should show up better.
Hello Elise, I think that there is a translation problem! Those are pictures of the lens, which is clean for sure but the concern is that the sensor on the camera might have dust on it. Dust on the back of the lens isn’t a good thing but wouldn’t show up directly on your images, dust on the sensor can do though, particularly at small apertures like f11 which you say you are using.
…you can check for sensor dust with a (phone) torch and perhaps a magnifier but don’t try and clean it until you have all the right materials to hand, or take it somewhere, the sensor is easily damaged. If there is dust then a blower brush might be all you need, but don’t touch the sensor with it.
Elise, to check for dust on sensor , you point the camera toward evenly lit object - sky, piece of white paper, etc, defocus the lens(!), close aperture down as small as you can ( f16, f22, f32) and shoot. Shutter speed and camera shake does not matter . The dust will appear as sort of dirty spots on otherwise grey background. Any lens will do for the exercise.
