Fresnels

[brucep]

Has anyone any experiance of these slim fresnals:

http://lensn2shutter.com/fresnels.html

and does the thinness really not matter for landscape photography on a 10x8.

What is the company like to work with, as I've been waiting a few days now for a response to my email for pricing.

Thanks

[IanG]

I've communicated with them a few times, they get their fresnels made in batches. Note that they don't sell a 10x8 fresnel.

My own preference is to use a fresnel but a better ground glass screen can add significant brightness and make a camera much easier to use. My 10x8 Agfa Ansco Commercial View camee with a new Beattie screen and it's great to use however the screen on my secong Afgfa Ansco (a Universal) is bright and still not hard to use.

You'd need to look at Chinese made fresnels if you want to go down that route, I've bought one for a 5x4 camera and along with a better GG screen the combination is over 3 stops brighter than the original manufacturers screen.

Ian

[brucep]

Thanks, I hadn't actually noticed the "UNDER" 10x8.

Bruce

[vinny]

Here's what I've used on my 8x10 for several years: http://www.staples.com/Bausch-Lomb-Magna-Page-Full-Page-Magnifier/product_251959
There's a guy who sells them on ebay (trimmed) for $$ sometimes but I don't see a listing now.

[Bob Salomon]

What matters, and really what only matters, is the focal length of the Fresnel and what range of lens focal lengths it is designed to work with.

If you have the wrong focal length Fresnel for the lenses you work with the image can black out as you move your eye around the gg or the ability to snap in and out of focus can be lost. Camera manufacturer's Fresnels are usually made to work with the most common lenses for the format camera you are using.

[Jim Jones]

A check of a few sheet magnifiers from office supply sources suggests that the ones Bruce linked to may be somewhat better. Thickness of the office supply magnifiers is .020" to .022", compared to the .018" in the link. A .018" thick magnifier would induce about a .012 focusing error, which is about the tolerance of film holders. Groove spacing is usually 2 lines /mm, not as good as the 3.3 lines/mm in the link. One of mine has groove spacing of 4 lines/mm. Focal length of each of mine is about 10", not very useful for wide angle lenses. All are slightly smaller than 8x10".

[Cletus]

I "made" a fresnel for my Sinar 8x10 (which is closer to 9x12 than 8x10) from an office store "reading magnifier" and it actually worked quite well. Beware though, if you intend to go this route - the type of plastic these are made from is very brittle polycarbonate type stuff. It's hard to cut! Especially if you only need to trim 1/4" or less off an edge. I did it by repeatedly 'scoring' it with a sharp utility knife along the edge I wanted to remove until I had a good deep score in the plastic. After that, snapping the edge off with a flat-nosed plier, like a lineman's plier and then smoothing the (very) sharp edge with Emory cloth. My first attempt to cut down the fresnel shattered it into a dozen wicked sharp pieces.