Isn't this how macro is done anyway? set the magnification ratio on the lens and focus with the distance to the object?
Isn't this how macro is done anyway? set the magnification ratio on the lens and focus with the distance to the object?I manually focus every frame and check it on the screen at 10x. I don’t change the focus on the lens, which could change the scale or introduce distortion, but I use a Linhof macro rail on my copy stand for fine focus by moving the camera.
Fluorescent bulbs are not a continuous light source - they are modulated at 50 or 60 Hz (mains frequency). if your exposure catches a time when the bulb does not emit any light you will get dark banding. To prevent against this you can increase exposure time. Another alternative is to use a continuous light source such as LED with a continuous power supply (battery or regulated mains power supply).I'm curious as to how the backlight chosen to illuminate your film (prior to photographing with the dslr) affects your picture? Obviously it could colour your image. Sometimes I've also noted that fluorescent bulbs and digital cameras don't play well together resulting in a dark banding. Do people run into this with dslr scanning? I used to have this issue with my xray viewer and phone camera not playing well together.
Fluorescent bulbs are not a continuous light source - they are modulated at 50 or 60 Hz (mains frequency). if your exposure catches a time when the bulb does not emit any light you will get dark banding. To prevent against this you can increase exposure time. Another alternative is to use a continuous light source such as LED with a continuous power supply (battery or regulated mains power supply).
The color of the light source indeed has an influence on the picture. Ideally the light source's color should be located on the Planckian locus, i.e. the black body radiation (the black line on the chromaticity diagram below). Then you can correct it with the color temperature setting of your camera or RAW-processing software. If the color of the light source is not on the Planckian locus, you cannot correct the color cast by means of the color temperature setting. This is why the color temp setting cannot compensate for the color cast of color negative films.
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I use a white LED light box. Its advertised color temperature is 5500K. Before scanning I take a couple shots of the "empty" light box with various exposure times and use this as a white point reference for RAW conversion of the scanned images.
See:
https://en.wikipedia.org/wiki/Black-body_radiation
https://en.wikipedia.org/wiki/Planckian_locus
In my experience the best of the Betterscanning film holders (I tried all except liquid) was the adjustable version. Fussy process using many tiny screws to get finest focus (once-and-done).
The color of the light source indeed has an influence on the picture.
I use a white LED light box. Its advertised color temperature is 5500K. Before scanning I take a couple shots of the "empty" light box with various exposure times and use this as a white point reference for RAW conversion of the scanned images.
I have an Epson v550 that I got on the cheap for $50, but I've been considering getting a macro lens for doing DSLR scanning. Some people claim the scans are better but is this true?
I also want to do 120 scans...lots of question marks on the setup which has been delaying me from doing it.
Also some people claim it's faster, but I've talked to some that say they don't like the workflow. Inverting the colors and removing the color cast was too tedious for them.
What do you all thing? Do you prefer it and is the effort worth a vastly increased IQ with DSLR scanning (I've got a full frame camera but no macro lens at the moment) or is this a myth?
Don't dim the LED and they are constant. Their spectrum isn't all that great though. I would use flash or quart lamp.I don't know much about LEDs. I don't think LEDs are a constant source because if they are dimmed, the electronics turn them off an on to create an illusion of dimming with the duty cycle. The longer the cycle, the brighter the light.
Do you have a recommendation for an LED that works well for color film? (They are very convenient to use, for sure.)
I use a cheap Kaiser Slimlite LED which does not seem to be in production anymore (I could not find it on their website).I don't know much about LEDs. I don't think LEDs are a constant source because if they are dimmed, the electronics turn them off an on to create an illusion of dimming with the duty cycle. The longer the cycle, the brighter the light.
Isn't this how macro is done anyway? set the magnification ratio on the lens and focus with the distance to the object?
Absolutely true. A flash is much closer to daylight!Don't dim the LED and they are constant. Their spectrum isn't all that great though. I would use flash or quart lamp.
The author of the Negative Lab Pro plugin has a page discussing the merits and defects of various light sources for dslr scanning <click here>I'm curious as to how the backlight chosen to illuminate your film (prior to photographing with the dslr) affects your picture? Obviously it could colour your image. Sometimes I've also noted that fluorescent bulbs and digital cameras don't play well together resulting in a dark banding. Do people run into this with dslr scanning? I used to have this issue with my xray viewer and phone camera not playing well together.
The author of the Negative Lab Pro plugin has a page discussing the merits and defects of various light sources for dslr scanning <click here>
He recommends daylight. The Durst slide copier is halogen, and I believe it uses a 3400 K EFP tungsten/halogen/bulb. He recommended 4700K for a daylight halogen. Maybe I could "dial in" daylight (may be tough), or the Durst also has a slide out filter drawer for color corrections. So far I seem to be ok with camera WB, but am not checking critically. I imagine the Durst was designed properly (maybe for tungsten film originally?).
I don't think the color temperature doesn't matter because digital sensors are white balanced for the light source.
Great info. I didn't know there was a native white balance. Makes sense because there's also native speed of sensors too. The bump in speed from my understanding is through signal amplification. My question is it better to shoot or in this scan in this case at the native white balance or not? Is it similar to digital zooms where there's digital trickery?Digital sensors actually have a native white balance where there doesn't need to be multipliers applied to each channel to get to white. This varies from camera to camera. Most modern cameras usually are natively around 5000K-5500K.
Also, white balance happens on two axis: green/magenta, and Amber/Blue (or Yellow/Blue, the depends on the implementation).
Great info. I didn't know there was a native white balance. Makes sense because there's also native speed of sensors too. The bump in speed from my understanding is through signal amplification. My question is it better to shoot or in this scan in this case at the native white balance or not? Is it similar to digital zooms where there's digital trickery?
Lots of information there. Thanks for posting.The author of the Negative Lab Pro plugin has a page discussing the merits and defects of various light sources for dslr scanning <click here>
The way I read it, Nate seems to emphasizing the importance of a high CRI, over color temperature.
One thing I came to understand recently as a result of one of the recent Photrio threads on DSLR scanning is that this is actually incorrect.I probably need to read it again more carefully, but it seemed that high CRI was also tied to having an appropriate color temperature.
Lots of information there. Thanks for posting.
Yes. The color temp of quartz halogen light is lower than daylight but can be corrected in the RAW converter or using filter because its spectrum is of a black body radiation.Absolutely true. A flash is much closer to daylight!
With quartz lamp, do you mean halogen lamp?
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