Yanke Ultra Bright Fresnel+Acrylic - Installation

[bekah1964]

I have a Linhof Super Technicka IV and recently purchased a frensel +acrylic screen to brighten the GG....it didn't come with instructions.

Can anyone give me instructions for installation?

Do I REPLACE the existing ground glass?

I saw in another thread that I am supposed to put the fresnel (frosted side towards lens) in first, then the acrylic....but do I completely remove the ground glass (and safeguard for later)?

Thanks in advance for the assistance.

[Ari]

Yes, remove your old ground glass, this is ground glass replacement, after all :)
Frosted side toward the lens, clear acrylic on top of the GG (closest to you), and you're ready.
Make sure the grid lines are parallel to the metal frame before tightening everything up.

I like the Yanke even better than a Maxwell, which used to sit on my Technikardan.

[bekah1964]

Thanks!

[Bob Salomon]

You have a IV and, if your IV has a fresnel, it was placed under the ground glass (today it is on top of the ground glass). The gg in a Linhof rests on 4 adjustable shims. If your camera has the old fresnel under the gg you can not just remove it and drop your new screen on the shims as they have to be re-positioned by the service center to place the focus side of your new screen in the proper position.

If your camera did not have a fresnel under the gg then you can just drop your new screen on the shims, image forming side on the shims.

[nicemate1]

Yes, remove your old ground glass, this is ground glass replacement, after all :)
Frosted side toward the lens, clear acrylic on top of the GG (closest to you), and you're ready.
Make sure the grid lines are parallel to the metal frame before tightening everything up.

I like the Yanke even better than a Maxwell, which used to sit on my Technikardan.

Dear Ari, I am replying to this "old" thread as I see that you have been using a Yanke viewing set in recent times.

I am thinking of purchasing one for my Horseman 45HD, which originally came with a GG on the "viewer side" and a Fresnel lens between the GG and the lens, and was hoping I could get some clarifications on how the Yanke system works.

As far as I understand, Yanke sells not just one piece, but a "set", composed by two screens, one with the gridlines on it and the other one transparent. (I am pasting an updated link down below). At least from the images on that ad, it seems that the screen with the grid lines on it is also a Fresnel lens, because you can also see the circular grooves typical of a Fresnel lens.
Having said that, and considering Bob Salomon's observation, in the sense that it makes sense that you cannot just change the order and distances of screens your camera was factory calibrated to, hoping that the focus will just stay the same, my question is: what is the sense of the second, transparent screen that Yanke supplies in it's set? Is it just a protection for the GG that incorporates the Fresnel, or is THAT the GG on the surface of which you are actually setting your focus?
Thank you for your kind help,

Pietro

(http://www.ebay.co.uk/itm/Yanke-Super-Bright-Fresnel-Ground-Glass-For-Sinar-Toyo-Horseman-Wista-4x5-Camera/172279606826?epid=1095531874&hash=item281caa2e2a:g:JGcAAOSwq7JUKnKH)

[Ari]

Hi Pietro,
I no longer have the same cameras as before, so the Yanke screen is also gone.
The set is: ground glass and clear glass with grid.
The clear glass goes atop the ground glass (closer to you) and it helps in seeing the ground glass better. At least the aerial image (the whole screen) was better with it on.
What do you focus on? The same plane where your film will go, which should be the ground side of the ground glass (away from you).
Bob would tell you to draw a tiny pencil mark on the rough side of the GG, then focus on it with your loupe, and you're good to go.