Digitize thousands (~7500) mounted 35mm slides as quickly as possible (without using a paid service), about 1,000 before Father's Day.
Kodak Carousel 750H Projector Nikon D5100 Nikon 35mm f/1.8G AF-S DX Lens Nikon 8-55mm f/3.5-5.6 AF-S DX VR Nikkor Zoom Lens Nikon 40mm f/2.8G AF-S DX Micro NIKKOR Lens
I own a CanoScan 9000F MKII (flatbed scanner capable of 9600dpi film/slide scanning), but the very slow speed combined with having to accept either lots of uncorrected imperfections (40-50 year old slides) or even worse "corrected" imperfections lead me to look for another solution.
I had all of the above except the 40mm Micro Lens. I had seen some fantastic results from numerous different individuals online that had successfully used a dslr w/ macro lens and a projector (optics removed, diffuser added) to digitize their slide collections. For clarity, the camera lens is aimed directly at the backlit slide.
After doing my best to copy the successful setups, the results were poor at best. The biggest problem is that the 40mm lens was a mistake-- it can't even begin to fill the frame at 8 or so inches (integral plastic housing where the projector's lens would normally be takes up the majority of this distance). When focused, the slide occupies less than one third of the image. Amazingly, the images look good, but 1/3 times my 16.2 mp isn't good enough.
At this point I am gun shy to rush out and buy another lens without doing my homework and knowing absolutely it will work (can't afford to lose the time or the money). I know there must be a simple set of equations that would answer my question, but knowing that my camera has a cropped sensor (DX) doesn't help me at all.
Question (restated, finally):
What lens is capable of filling the frame with a subject the size of a 35mm slide (film part only) on a Nikon D5100 at a distance of approximately 8" (PLUS the length of the lens) while keeping the depth of field at a minimum (thinking 2.8)?
If there is any additional information I can provide that will help, please let me know. My Dad is getting old, and I want this to be a special Father's Day for him.
Thank you very much.