Depending on your pocketbook there are two good choices.
One is to purchase a Betterscanning mounting station. The station provides an easy mechanism for setting the holder to the plane of best focus, and it also allows for flat mounting, either dry or wet, to the underside of a piece of glass. The station works vere well.
Another solution is to purchase a piece of AN glass (anti-glare glass from framing shop works ok for this) cut to a size that will allow it to fit over the existing glass of your scanner. Then you use small washers to determine the plane of best focus, and you can mount the negative to the AN side of the glass dry mount, or fluid mount if you like.
The best plane of focus of Epson 4990 varies from about 1mm to as high as 2.5mm above the glass. If you lay the negative directly on the glass you you not have the best position for optimum sharpness.
Sandy King
Thank you very much Sandy, I went over the Betterscanning web site and believe that this is the best way to go. I sent them a request for the formats I intend to scan. It appears that like an adjustable focus screen on a camera the scanner too has to be checked and adjusted for the optimum focus. I like that, it gives me confidence that the system is accurate and professional.
I'm starting out with this scanner and will upgrade later to a higher grade model. As you may know from the other Carbon forums I've just started Carbon Transfer photography and have after three sessions and five prints finally made my first Carbon Print. Not perfect in any sense but an intact complete image with relief and it's beautiful to me.
I have come to believe that the process can be learned in days or weeks, refined in years and mastered in decades. It's a great alternative to what I always wanted to do but the timing was wrong and the materials came and went and I grew too old to start from scratch, not enough time. That process is/was Dye Transfer. Given that I was prepared to spend considerable amounts of time on it I feel that Carbon is right for me at this time.
I'm using in-camera negative now but I feel that I will have little choice but to learn and go with digital negative in the future because I will most likely be using a Mamiya 7II and scanning do to my physical condition, age and the need to travel.
It may just come together for me at last, now to look at a beginner printer for Pictorico. I may have to sell a lot of my film camera systems to pare down to the essentials to make room for prints, prints, prints.
Thanks,
Curt