Glassless V700 - Bye Bye to newton ring!

[jack_hui]

I guess most of the V700/V750 users have newton problem when scanning 8x10 film.
I hate to see it and decided to find the solution - remove the glass and custom make a mount for 8x10 film. (As most of my works are 8x10 film, i.e. my solution is for 8x10 film only)

1) First, we have to remove the screw cover (four of them) from the top cover. You can use strong tape to remove it. It doesn't damage the cover, i.e. Epson won't know that you had removed the cover!!!



2) After that, remove the screw underneath and take out the top cover.



3) There are 6 clips that hold the glass, remove them all.



4) Next, we need to remove the glass from the strong tape. Use lighter fuel and soften the tap, it takes some time!! (You can always use your hammer, if you are in hurry! LOL!)

[jack_hui]

5) After that, screw back the top cover.



6) This is my custom make mount that can hold 8x10 film on it, which has 4 screw on the sides to adjust the scanning height.





Anti-Newton Ring glass can also be used on top of that to flatten the film.

[jack_hui]

7) End product at work.




After I fine tune the scanning height, I can find out the "best" height, but the difference are NOT huge, and the end result doesn't impove that much as compare with the glass on. However, I won't need to worry about the newton ring forever.

When I have time, I will make an adapter for 4x5 and other format.

Have a nice day!!!
Jack

[Gem Singer]

I use Ilford HP-5+ film, exclusively. However, most B&W film has a dull emulsion side and a shiny base side.

I place the 5x7 or 8x10 film, emulsion side down, directly on the scanner glass and place a sheet of anti-Newton glass, dull side down, over the shiny base side of the film.

I tell my Epson V750 scanner that I'm scanning a B&W negative directly on the scanner glass. Not using a negative holder.

Focus is sharp. Film is held flat. No Newton rings. No need to dismantle the scanner and remove the glass.

If you are using color film, or a film that is shiny on both the emulsion and the base side, all bets are off.

[jack_hui]

Singer:

I used several films, HP5 got no problem (most of the time), EFKE 50 sheet film ...... got problem (most of the time), negative /postive film .....never escape from newton ring, unless I don't use anti-newton ring glass ...... but ....

[Gem Singer]

Hui,

Read the last sentence in my post.

What I was attempting to say is that there is no need to dismantle an Epson 700 series scanner and remove the glass if you are scanning 8x10 film that has a dull emulsion side.

The Newton Ring problem only exists if both sides of the film are shiny, such as with color transparency film, etc.

Shiny film surface to shiny glass surface= Newton Rings.

[Eric Woodbury]

Shiny film surface to shiny glass surface= Newton Rings.

Only if the light is somewhat coherent. It is the differential path length of coherent light that forms the rings. If you replace the top glass in the scanner with diffuse glass (2447 plexi), the Newton Rings will go away. This extra layer of diffusion will diminish the light, but typically scanners have plenty of range.

[tjshot]

I was considering a similar modification on a V750 I'm going to buy.
After having borrowed/tested both a V700 and V750 on few MF and LF slides, I'm convinced that main issues with this (otherwise good) flatbed models are aberrations (LCA ang ghosting), visible at high contrast edges (low frequencies) and less so at higher frequencies (partially masked by loss of resolving power?).
This behaviour may imply problems with light diffusion and reflections between internal surfaces (base glass, mirrors, CCD glass, shiny surfaces).
If this is the case, removing the base glass would reduce aberrations and ghosting a lot, improving sharpness (low freq MTF) but not resolution (the high order rolloff of optics will mask every high freq. improovement).
Of course to really evaluate differences, a good scan target and very accurate focus plane calibration is necessary.
Did you notice any benefit in real use from suppression of aberrations on high contrast edges?
An interesting solution for 4x5 and smaller formats would be cutting a rectangular opening in a matt black plate to use as a scanning base instead of the glass; optimal would be painting internal surfaces also, to elimininate any residual light.
It did work for film enlargers back at the times, I bet difference would be relevant.

[Frank Petronio]

He's in Texas where there is zero humidity, so less chances for Newton's Rings to form.

I wonder if you can notice any sharpness benefits?

And whether the sensor will get dirty over time?

It seems like a good idea and I'm glad you tried it first so we don't have to!

[Ben Syverson]

I've thought about this before, but I like Frank I'm nervous about the sensor.

Jack, if you're already mounting the negative to ANR glass, why would you get Newton Rings? Just suspend the sheet of ANR above the scanner glass with four spacers...