ANR Glass - 2 or 1+regular for neg sandwich?

Hi Folks,

I've got some 6x12 Shanghai negs which are very curly and wont lay flat in the neg carrier. I was thinking of sandwiching these between glass for enlarging and would like to order some ANR Glass for it.

Now my question is - do I need 2 pieces of ANR or just one plus a regular non-ANR piece?

I'm thinking that I can place the neg EM down on the regular glass with the ANR glass on top with the dull side in contact with the non-emulsion side fo the neg. Or would it be better to have it sandwiched between 2 pieces of ANR glass? Or should the emulsion be in contact with the ANR glass?

I do not have a glassed neg carrier, or a carrier for the 6x12, I was using the 4x5 carrier. I was thinking to just use the 2 pieces of glass and black tape the edges so the light doesn't leak around the exposed glass outside the enlarger. This will be used in a Beseler 45MX II that I just picked up.

Hope I'm not overthinking this, just want to make sure before I order the glass. What's are my options?

Probably can get away with regular glass on the bottom.

I made a glass carrier for my old Minolta enlarger constructed from some old 4x5 glass just as you have described and it works very well. My Minolta has foam surfaces to squeeze the glass carrier. I used two AN pieces, but thats just what I had laying around at the time.

I agree with ic-racer, Newton Rings are a result of optical interference patterns when the two surfaces are spaced near a fraction of the light wavelength. As such they are far more likely to be a problem between the glass and the super-slick base side of the film than when contacting the emulsion.

DaveT

Thanks for the confirmation guys, appreciate it. Just wanted to make sure before I place the order.

Ic-racer, you just reminded me, my MX doesn't have any foam on the carrier, I'll have to line it to prevent scratches. I have some of that black craft foam in sheets that will work.

You could also put the foam on the glass, rather on the enlarger. McMaster Carr has foam as thin as 1/32". Tape might be better to protect the bottom, as foam will likely compress unevenly around the perimeter and alter the alignment of the glass frame to the enlarger frame. Just something to be aware of. That's how mine is, there is foam between the top of the glass and the light mixing box, and I used vinyl tape to protect the bottom of the glass.