Biogon 75mm f/4.5 lens shade - DIY

[Jac@stafford.net]

After learning that there is probably no such thing as a lens shade for the Zeiss Biogon 75mm f/4.5 lens, I put together a nice substitute. Actually, I made two.

If you wish to make your own - It is a 100mm Linhof slip-on filter without the glass, wedded (cemented) to a large, round wide-angle lens shade. This permits the use of a slim 95mm screw-in filter or the standard 100mm slip-on filters.

If there is interest I can make a snapshot of one to show here.

jjs

[JosephBurke]

Probably not too many owners of such a highly sought lens but I also do happen to have one. I'd be interested in seeing the pics.

[Jac@stafford.net]

Probably not too many owners of such a highly sought lens but I also do happen to have one. I'd be interested in seeing the pics.

I am a biogon freak. In a separate thread I can discuss another one for LF.

Here are two snapshots.

86657 86658

[Jac@stafford.net]

Not so interesting?
.

[C. D. Keth]

It's a lens shade, alright.

[Jac@stafford.net]

I would rather have a rectangular shade, but I have no clue on how one would go about determining its dimensions, angle of the sides. Any help from Net Wisdom?

[Mike McMullen]

Since you guys have this lens, could you give me some advice as I am considering buying one: I am okay with the weight and limited movement, but is the sharpness and even light dispersion significantly superior to a Super Angulon to justify the cost? They are going for $2,700 and up. Thanks.

[Jac@stafford.net]

One characteristic of the Biogon is that coverage does not increase with stopping down. I appreciate its speed and easy focusing. Yes, it is sharp. Regarding light fall-off I conservatively put it at about 1.5 stops which is better than the Super-Agulon. People who claim there is no fall-off must have different Biogons than I use, and I use three of them. Contrary to another myth, it can distort parts of the image closer to the camera and offset from center. At infinity distortion is negligible when parallel with the subject. The Biogon was very popular as an aerial camera lens because of its low distortion and also for its speed. (To certify as an aerial mapping lens, a lens must be shot wide open regardless of whether it has an adjustable aperture.)

http://www.digoliardi.net/two_biogon_75mm.jpg

The 3" Biogon on the right is unusual in that the rear lens is larger than 4" of 4x5" film. In fact, it peaks over the top. So this one defeats some of the fall-off characteristic of the lens by simply being very large. The text in the picture is incorrect - it should read coverage is an easy 5x5".

[Cpt Buggernuts]

I would rather have a rectangular shade, but I have no clue on how one would go about determining its dimensions, angle of the sides. Any help from Net Wisdom?

I think I have a simple solution.
Fix the lens on your camera, and raise/shift it until you see the edges of the lens projection on the ground glass. Then create a cardboard mockup of the hood so that it doesn't enter the frame.
From then you can work on the manufacturing process to your liking :)