best wide angle fresnel

What is the best fresnel for wide angle photography? I have read

about Maxwell's custom fresnel's. How do they compare to Beattie or

others?

 

We are using sinar F2 4x5. Our 90mm Super Angulon is only an f8 which

makes things difficult for composing in low light conditions.

 

Regards,

David Rosenbloom

I recently got a Maxwell screen to use with my Toho MC-45X. I've used it with a 90 mm f/6.8 lens. The image is extremely bright and you can see easily in the corners. It would be a little dimmer at f/8, but still very easy to use.

 

Before I had a rather coarse plain ground glass. The Maxwell screen went just precisely where the other screen was without any adjustments. (It was thicker with the protective glass so I needed some longer screws.)

Have you tried the Sinar fresnel? I found that it worked fine for my wide angle lenses on my Sinar C2.

ellis,

 

yes, I have the sinar fresnel. still seems to dim for composing, particualrly at the edges.

 

One issue that concerns me with aftermarket screens is the issue of film plane matching the focus plane. I have heard of Beattie screens being several mm off producing soft images.

 

dr

I have a regular Maxwell screen and with the 90/f8 its still pretty dim in low light. Bill does make a screen just for use with wide angle lens that's supposely brighter.

If the fresnel is on the outside of the GG, ie, where you would place the loupe, you should be fine. The "fresnel focus shift" issue comes into play when the fresnel is mounted between the GG and the lens. Cameras such as my Arca, are built this way and the placement of the actual GG is compensated for to allow for this internal fresnel. There is a mathematical formual used for placement of the GG, I've heard something like 1/3 of the thichness of the fresnel, but that may be dependent upon the fresnel's lens specifications. When using an internal fresnel, neither the actual GG nor the fresnel reside at the same plane as the film does. If you have a standard GG with an external fresnel, the "etched" side, or inside of the GG, will be at the same plane as the film. I would contact a factory authorized service center for your camera.

My Beattie Intenscreen Plus is absolutely in contact with the protection glass that cover the fresnel... I think it isn't out of the focus plane. It's made of plastic, perhaps more used ones could have a little bend, it isn't my case (I bought it five years ago).

 

I find this screen a bit grainy, and a bit hard to focus. I am looking for another GG&fresnel with a smaller grain. Perhaps the Boss screens work better. I would like to hear another opinions.

 

With my Grandagon 75, corners appears something dark. I find it so brigth with the 110 and up.

 

Good luck,

i've never found a solution to this problem. i currently use a beattie intenscreen with a maxwell fresnel, and it is the best i have seen, but it still is dark in the corners even with a 90mm. i tried a few other types of screens including the boss and others that use the two-plate system (sealed with some type of wax between the plates) - i could not use any of those due to temperature fluctuations causing little bubbles to form in the wax substrate. the problem is of course exacerbated when shifting, and as far as i can tell, it is just something us LF nutcases have to put up with to do the work we do.

After looking at the other answers I went back to try out my Maxwell screen with a 90 mm lens at f/8. I lit up my living room with two photofloods so the white walls were at 8 with my Pentax Digital spotmeter and the deepest shadows were about 3. Shooting at 250, I would have exposed at something like 2 seconds at f/16. That is about as dark a scene as I would normally be working with. I wouldn't call the resulting image exactly bright, but I could easily see everything I needed to see, and it was well illuminated from corner to corner. With a 4 X loupe I could easily focus on critical detail. And I don't see that well in dim light.

leonard,

 

thanks for the input. Do you have the general purpose maxwell 4.7 screen or his wide angle model?

 

dr

Leonard,

 

You've just about convinced me to go with Maxwell for my Toho. Which screen, and which screws, did you end up with?

 

How well does your screen work on longer lenses, say 240mm and up?

David I have a maxwell screen for my deardorff 5x7 and it is a great screen. I'm sure you have heard of the trick of putting vaseline on the ground glass and wiping clean. I did that with my old ground glass screen and the brightness was great however the hot spot is greater! Bill Maxwells normal screen overall is not that bright but it is very even and is excellent to use. The lens I was worried about when I ordered my screen was a 120mm f8 that is about the same as a 90mm f8 on a 4x5. Bill still recommended his normal screen and not the wide angle screen. However if you plan on using lenses shorter then the 90mm quite a bit I think he will tell you to go with the wide angle screen. Bill said that the special wide angle screens will not be as good with a normal lens but if strictly plan on using the 90mm maybe he wil advise other wise. I would give Bill a call and I hope you have a good lond distance rates because you could end up with a hefty phone bill. Bill Maxwell is a great guy with even better screens!!

To Jose, about Bosscreens:

 

The Bosscreen won't solve your problem. It has a strong hot spot with short lenses, quite disturbing even with a 100 mm Apo-Symmar. Since I don't want to invest into another GG, I bought an Ebony wide-angle Fresnel, which is placed outside, on top of the Bosscreen. It solves the problem perfectly with my 100 mm (and would probably with a 90 mm lens too), but it still isn't enough with my Grandagon 75 mm.

after all the good input, gave bill maxwell a call and my screen arrived today. It is better than I expected. Not just brighter and better illuminated in the corners, but a beautilful crisp image. This compared to the sinar fresnel and GG.

 

Bill was a pleasure to deal with. He can talk to you all day about glass and light.

 

thanks again,

david rosenbloom