How to make this?

[Dan]

I'm interested in printing some 4x5 negs full frame and thought about making my own negative carrier by sandwiching two pieces of glass, with one being AN glass. I'd then mask the excess carrier to make an area for the negative to fit into. My question is this: I seem to remember that only one of the pieces of glass needs to be Anti-Newton and that it matters if it's the top or bottom. Anyone have suggestions?

Dan

 

[clogz]

The top piece of glass should be AN.

 

[Loose Gravel]

If you are using coldlight, make the top piece out of white plexiglass. Cheaper and easier to find than AN glass. Then remove the diffuser on the bottom of the coldlight. This is how my 8x10 works enlarger - light - neg holder works.

 

[Dan]

If you are using coldlight, make the top piece out of white plexiglass. Cheaper and easier to find than AN glass. Then remove the diffuser on the bottom of the coldlight. This is how my 8x10 works enlarger - light - neg holder works.

why not just use a clear piece of plexy coupled with anti-glare glass on the bottom, then? What's the advantage of your suggestion?

 

[Loose Gravel]

The advantage is, it works and it's cheap.

If you are using a coldlight, although it is diffuse, there needs to be a more full diffusion or you will see the grid in your image. If the diffusor is in contact with the negative's top surface, newton rings cannot form because of the location of the diffusor and how newton rings form. So it's not that the top material is plexi and the bottom material is glass, it's that its a diffuse source in contact with your neg and coherent reflections cannot form. Newton rings don't form on the bottom, because the negative on the bottom is not smooth enough to allow the surfaces to get close enough together to get coherent reflections. It also reduces dust problems above the negative.

 

[Dan]

Now I'm starting to get it...you're saying using diffused plexy for the top half of the carrier won't cause Newton rings. Do I have to replace the coldlight plexy with someting clear or can I just print with nothing between the tubes and the negative carrier diffused plexy top? Sounds like a much better (i.e. cheaper!) solution...thanks.

 

[Bob Carnie]

Dan
I see no problem with your idea, Showing the rebate or film edges does require a sandwich of glass on certain enlargers 4x5. I would suggest putting the AN on the top. Focal Point in Florida has this glass.