V700 Scan Sandwich: BtrScning Wet Dry Station, Extra ANR Glass

[Brent Long]

I like the idea proposed in another thread about sandwiching film between two pieces of glass with ANR coatings contacting the film. I'm thinking the Betterscanning Wet/Dry Mounting Station, with an extra piece of ANR glass, would be ideal. I really don't want to try to tape my MF negs to the glass as there isn't much of an edge around my 6x9s.

I know another member here does this, though with the supplied Epson V750 Wet mount (non ANR, but with B/W film emulsion contacting that glass) and another ANR glass on top. Are there any others who have done or are doing this? Is there just more badness going through even MORE glass???

Also as a note, my V700 seems to achieve best focus at around 4.5mm! In that case, wouldn't mounting on the bottom of the Wet/Dry station not allow me enough height for optimal focus? I don't know enough about the design of the BS holders, but I'd have to think the glass is thick enough to drop the film out of focus, without enough room left for adjustment back to the optimal height.

I'd like to place an order right now, but I thought I may be wiser to run this by some of you knowledgeable and helpful folks here first.

[Nathan Potter]

It is always slightly better to not scan through the mounting glass or the base of the film except in the case of wet mount technique. So for dry mounting I get best results using the Epson wet mount glass and taping the film to the underside of the glass with the emulsion facing out so it faces down on the scanner. Then the height of the film above the Epson glass platen has to be determined and adjusted for best focus. I use mat board spacers to get to the best height. BTW there is considerable DOF to the high resolution Epson lens, about +/- 0.5mm or so - you don't have to be super critical about the height.

Your 4.5 mm above the glass seems a bit higher than many which range from 3.0 to 4.0mm.

The wet mount technique seems to provide a slight improvement in contrast even though scan imaging is through a second layer of glass and fluid to the emulsion. I have presumed that the fluid is a somewhat index matched to the glass and film, so surface reflections are reduced.

OTOH just taping the film to a carrier glass will leave air gaps between film and carrier glass that can cause multiple reflections from the light source above and yield a lower contrast scan but only in principle. I have trouble quantifying the difference between a wet scan and an emulsion face down scan. I'm kinda guessing that the wet scan is superior in contrast.

Nate Potter, Austin TX.

[Brent Long]

Thanks. As for the 4.5mm optimum focus, I should state that it is somewhat preliminary because I was testing with curled film. When I have a good way to flatten it out I'll have to retest. The thing that really surprised me, however, other than the optimum focus seemingly being so high compared to others, is how little adjustment it took to see a difference. I was shimming with some thick paper, probably the thickness of an average business card. Epson holders at 3.5 plus three pieces made a huge difference. I then added another three and it was another huge difference. Adding just one more made it readily noticeable that it was getting softer. I backed off to four, and the difference between four and six was easy to see. I added another and it was really close, but I thought I saw that five pieces was a little better, so that's what I went with.

I haven't attempted to measure the thickness of one piece of paper accurately, but 5 cards comes to around 1mm, maybe a hair more. That puts one at about .2 mm. But, I could readily tell the difference between adding/subtracting two pieces, or around .4 or .45 mm. It therefore seems a little optimistic to say the DOF has +/- .5mm leeway.

Though, again, I need to retest with flatter film.

[sanking]

I like the idea proposed in another thread about sandwiching film between two pieces of glass with ANR coatings contacting the film. I'm thinking the Betterscanning Wet/Dry Mounting Station, with an extra piece of ANR glass, would be ideal. I really don't want to try to tape my MF negs to the glass as there isn't much of an edge around my 6x9s.



There is an easier way to do this IMO. You fluid mount the negative to the underside of the Betterscanning glass, then fluid mount a piece of thin mylar over the negative. Then tape the mylar to the glass. The mylar should be larger than the negative, but small enough so that you can tape it to the glass.

With the Beterscanning mounting station the glass is elevated slightly above the bed of the scanner to adjust for best plane of focus.

Sandy

[Nathan Potter]

Ah, Sandy, that seems like it might be a good technique. Which side is the emulsion on? Facing the Betterscanning glass or the mylar over layer. If facing the mylar then the lens only needs to image through the thin mylar and the fluid between the mylar and the film emulsion.

Nate Potter, Austin TX.

[sanking]

Nate,

I prefer to mount the negative so that the emulsion faces down, toward the CCD of the scanner. So yes, mounted this way the lens only needs to image through the thin mylar.

If you mount the negative emulsion facing down it be necessary to flip it in PS to get correct orientation. But in theory there seems to be an advantage to mounting emulsion side down, and that is the way it is done with professional high end flatbeds like the Eversmart.

In any event it is relatively easy to fluid mount this way with the Betterscanning holder.

Sandy







Ah, Sandy, that seems like it might be a good technique. Which side is the emulsion on? Facing the Betterscanning glass or the mylar over layer. If facing the mylar then the lens only needs to image through the thin mylar and the fluid between the mylar and the film emulsion.

Nate Potter, Austin TX.

[Brent Long]

Wow. Thanks, Sandy. This is precisely why I waited and brought my dilemma to the board. There are so many helpful and knowledgeable people.

Although . . . I was hoping to stay away from wet mounting as well, so my next question is how much effort, time, etc. am I looking at here, as well as extra cost and stuff? I guess the real question is, how much increase in image quality am I looking at with your suggested method, and then figuring out if it's worth it based on the image quality/extra time, money, effort ratio.

It would seem you think it worth it, but if you can give me some sort of idea (though I suppose this becomes rather subjective), from your perspective, it would be helpful. I had already settled on just ordering the BS wet/dry station only, and then adding another ANR glass later if it seemed it may be beneficial. Perhaps, though, with your recommendations, along with others, I can start assembling the wet mounting supplies I would need as well, while waiting for the station to show up in Japan.

That brings me to another question: Is there a way for me to test this method first without much layout, just to see if it's something I think worth doing? I did wet mount once before on an old Canoscan 8000F. I did it with baby oil. It did give me a better scan, but it was directly on the bed (best focus for the Canon), and it wasn't enough better to compel me to stick with it. I don't know if baby oil is a good idea, though, but someone had recommended it before.

[sanking]

Brent,

I have used baby oil and while it works clean-up is more difficult than with scanning fluid like Kami. Mineral oil cleans up faster and should work fine for testing in place of Kami. You could use a piece of plate glass cut to fit over the bed of your scanner, and adjust the height over the bed (with shims) for best focus. Now all you need to test is some thin mylar and tape. For fluid mounting with flatbeds (not drum scanners) I recommend 3m blue line tape as it leaves less residue than most other tapes. Learn the technique of fluid mounting with an old negative or transparency.

My experience is that fluid mounting, if done in combination with accurate adjustment of the mount for best plane of focus, can improve the quality of a scan with a consumer flatbed scanner like the Epson V700/750. The appearance of grain should be minimized, resolution should be slightly improved, and micro-contrast will be substantially improved.

A scan with an Epson V700/750 can not match one made with a professional flatbed or with a drum scanner. However, if you optimize results it may be good enough for your needs if you are scanning B&W or color negatives and don't enlarge more than about 4X-6X.

Sandy King

[Brent Long]

Again, Sandy, very, very helpful. Thank you. I think I'll give it a whirl. I don't know if I can get that tape locally, but I'm sure I can find something that'll work without leaving too much goo.

Truthfully, I'm very impressed with my V700. I compared a slide to my Canon FS4000US, and there really wasn't much between them. With careful sharpening, I could make them look almost identical.