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axs810
16-Jul-2015, 15:04
136982


I want to buy a new ground glass to replace the one that is in my Chamonix F1, but I want to know if anyone knows if I replace the 3 pieces of ground glass that are already in my F1 will that affect focusing? I want to put in a Steve Hopf Borosilicate GG or one of those new bohemastudio acrylic GG.
SMBooth
21-Jul-2015, 19:10
There is only one piece of ground glass in the Chamonix. Closest to lens seated in a cutout is a fresnel lens, then the GG in the middle, with a protection clear plate behind that closest to your face. You only need the middle ground glass. You can remove the fresnel and clear plate without effecting the focus point.
axs810
21-Jul-2015, 19:17
Thank you!!!
StoneNYC
21-Jul-2015, 19:20
The Chamonix GG is so bright and clear, what don't you like about it?
Kirk Gittings
21-Jul-2015, 19:22
The Glass protective sheet on the outside is irrelevant. So you have a fresnel on the inside of the GG. If you remove the inside fresnel, thereby moving the middle ground glass that much forward, would that not affect focus? Wouldn't you need to add a spacer to maintain the original position of the GG?
axs810
21-Jul-2015, 19:32
The Chamonix GG is so bright and clear, what don't you like about it?


It's not that I don't like it I just find the weird rings it produces from the GG touching each other annoying. Sorry I forgot what the correct term for the rings are...
StoneNYC
21-Jul-2015, 19:49
It's not that I don't like it I just find the weird rings it produces from the GG touching each other annoying. Sorry I forgot what the correct term for the rings are...

That's he fresnel. You can remove that, this the piece in between the GG and the outer protective glass.

Try just removing the fresnel in between, then replace the protective glass on top of the ground glass and you should be fine.
axs810
21-Jul-2015, 19:54
So wait the fresnel isn't the one closest to the lens? I'm confused now
StoneNYC
21-Jul-2015, 20:05
So wait the fresnel isn't the one closest to the lens? I'm confused now

It shouldn't be no, the older N-1's had them reversed and that caused focus problems and they fixed it.

I don't own an N-1, N-2, or F-1 but my 8x10 to 4x5 reducing back has the GG - fresnel - protective glass, in that order.
axs810
21-Jul-2015, 20:08
Oh ok gotchya. Thanks!

Is there any way to keep the GG/Fresnel/Protective glass combo without getting those weird rings that show up?
StoneNYC
21-Jul-2015, 20:13
The fresnel IS the "weird rings", just take the fresnel part out... :)
vinny
21-Jul-2015, 20:18
The fresnel IS the "weird rings", just take the fresnel part out... :)

Stone, No.
He's referring to the pattern that appears because of the pieces coming in contact with each other. Newton Rings.
axs810
21-Jul-2015, 20:21
Stone, No.
He's referring to the pattern that appears because of the pieces coming in contact with each other. Newton Rings.

Yeah that's what I'm referring to the newton rings.
StoneNYC
21-Jul-2015, 20:29
Stone, No.
He's referring to the pattern that appears because of the pieces coming in contact with each other. Newton Rings.

Newton rings? Really? Hmm... I've never seen that on my GG and it's essentially the same thing, that said of he's seeing those, then removing the protective glass would fix that, since the only two points of smooth to smooth contact are the back of the fresnel and the front of the protective glass.

Sorry I didn't think Newton Rings would be an issue even if they are there, to new that wouldn't matter on the GG (not enough to spend money on new stuff).

But my suggestion SHOULD work.

I'll have to check to see if I see Newton rings on mine.