4x5 View Finder?

[bobwysiwyg]

Bob, I have recently invested in an Ebony Wide Angle Fresnel - and its some of the best money I have spent.

I would recommend them to anyone

I can now easily see the image on the GG without the Darkcloth and with a Darkcloth it is realy realy bright

I find it helps when I check the GG composition - particularly in the corners

The Wide Angle Fresnel works on lens lenghts upto 150mm

I have an Ebony camera but it should fit OK with any other camera too - it goes your side of the ground glass, with the Fresnel lens on your side too.

You then need a Protective Glass to protect the Fresnel.

Martin

I found my way back to this post. I've acquired a Fresnel screen for my 4x5 and just want to make sure I understand this correctly, that is the order and facing of each.

1) Ground glass with the ground surface facing the lens.
2) On top of this, the Fresnel lens with the circular pattern facing the rear.
3) A protective cover for the Fresnel lens.

Seems to make for a fairly thick sandwich, but it should all fit under the retaining clips on the back..I hope.

Just looking for some verification, aka Newbie assurance.

[David A. Goldfarb]

It depends, but normally you want the groundglass in its original position, fresnel with the circular pattern facing the lens, and you may or may not use a protective cover or grid overlay over that. The main thing is that you don't change the location of the groundglass surface when you put in the fresnel, or it won't be at the film plane.

There are a few backs designed to have the fresnel between the lens and the groundglass, as on some Graflex/Graphic cameras.

[bobwysiwyg]

The main thing is that you don't change the location of the groundglass surface when you put in the fresnel, or it won't be at the film plane.

I wondered about that as I was putting it in the first time, Fesnel first (facing rear though), then ground glass. I wasn't sure how critical that diff. to the film plane would be. Now I know it is critical. All very confusing to this newbie. I thought one of the advantages to the Fresnel was to straighten/redirect light to the ground glass which is hard to understand how it will if mounted behind the GG. Even mounted incorrectly, the view was certainly brighter into the corners and out to the edges. I guess that's why folks like them.

[Trevor Crone]

I use the Ebony fresnel, it's behind the GG, the frosted side of the GG facing and nearest the lens. On top of the fresnal I have my grid glass protector. The fresnel spreds the light more evenly once its transmitted through the GG making it much easier to see into the very corners of images projected by very WA lenses such as the 47XL.

To summarise:
1) GG nearest lens, frosted surface facing lens.
2) Fresnel
3) Glass protector/grid.

[Bob F.]

<snip>
I thought one of the advantages to the Fresnel was to straighten/redirect light to the ground glass which is hard to understand how it will if mounted behind the GG. Even mounted incorrectly, the view was certainly brighter into the corners and out to the edges. I guess that's why folks like them.

Behind the ground glass it works the same way: directing the light towards your eye instead of off at an angle. Directing the light either before or after it strikes the ground surface gives essentially the same result. Putting it between the lens and the gg does afford the plastic Fresnel physical protection, but some have cover-glasses as mentioned above to do that job when mounted outside.

Cheers, Bob.