4x5 fresnel off ebay - any good?

[pramodh]

Has anybody tryed this?

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160015319071

 

I am worried it might throw the focus off on my wista

[michael_briggs2]

This seller offers thin Fresnels that he maintains can be placed in front of the ground glass. This will effect the focus. Because of the thinness of the Fresnel, some might find the offset acceptable. I don't think the idea is a good one.

 

Here are some previous discussions: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CIgP and http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00EuvB

[vinny_walsh]

I picked up a "full-page magnifier" from staples that is basically a 8.5x11 plastic fresnel

used for viewing maps. It's hard to cut but a few passes with a sharp utility knife does the

trick. Install over your current ground glass and it works quite well to even out the view

on my 90mm. For $8.45, it's worth a try.

 

http://www.staples.com/webapp/wcs/stores/servlet/StaplesSearch?

storeId=10001&catalogId=10051&langId=

-1&categoryId=10326&cmArea=SEARCH&searchClassId=10326&keyword=maps%2C+ma

gnifiers+%26+flags&actualKeyword=MAGNIFIER&searchSkuCount=12&compChartFlag=tru

e&searchUnsumUrl=searchresults&searchSumUrl=searchresultssummary&errorUrl=search

noresults&fromUrl=searchresultssummary&cmArea=SEARCH

[paulwainwrightphotography]

As an alternative (though not low priced), you might consider purchasing a focusing screen from Bill Maxwell at Maxwell Precision Optics: http://www.mattclara.com/maxwell/index.html - I have one of his 4x5 screens on my camera, and since it replaces the ground glass, there is no issue with shifting the focus of your image (I've checked). It is truely wonderful, and much brighter than a normal ground glass. I can do a lot of my initial composition without a dark cloth, AND (the big selling point for me) I can see the entire image from corner to corner (even with my shorter lenses) without moving my head all around. I highly recommend Maxwell's screens (and I receive no royalties - I'm just a happy customer).

[robert_meyer3]

I brought a fresnel lens from the same supplier on Ebay (lensn2shutter) that you asked about. I had it made to the same size as the ground glass in my 4x5 RB Auto Graflex. I just loosened the clips that hold the ground glass and put it on top of the ground glass that's there already. The existing clips hold the GG and fresnel in place without any problems. There was no shift of focus that I can tell. It gained me about 1 stop in brightness, or maybe a little more. The brightness of this camera is now comparable to that of my Graflex Super D's (both 3 1/4 x 4 1/4 and 4x5). The Super D's were made with special view screens to enhance brightness. While the fresnels are too expensive to add to all my Graflexes (I probably have 10-15), I have been thinking about having one made for my 5x7 Auto Graflex.

[michael_briggs2]

Robert, from your description you have installed your Fresnel in between the ground glass and the photographer. In this location it won't shift the focus. lensn2shutter instructions are to place the the Fresnel in front of the ground glass, between the lens and ground glass -- this location will alter the focus if added to a ground glass that didn't have a Fresnel.

[shadowleaves]

<p>The best option is to purchase a Sinar 4x5 fresnel (around $60 on ebay), which has a clear (no fresnel) center spot. Since the clear center spot will not affect the light path in any way, this fresnel can be placed between the lens and ground glass without jeopardizing the focus accuracy.</p>