Proper shading of LF and ULF lenses

[Helen Bach]

There's a long-ish thread on the design of decent lens hoods here on APUG. It has differing opinions - one of the great advantages of the net over printed material. It also contains formulae and a diagram or two.

Fortunately as well as the simple and quick Lee hood system I also have Petroff, Van Diemen, Bolex and Chroszeil matte boxes to play with, and they have a variety of barn doors, eyebrows, mattes etc. Black Cinefoil (heavyweight matte black aluminium foil) works with the likes of the Ebony shade clip thing - Cinefoil can be folded and refolded a few times, it holds its position well and it is cheap to replace. Small mattes for the Lee system can be fitted to the front of the hood, and slid vertically in the grooves.

Later: I've just fished out what I think is a Lowel eight-leaf barn door (four double leaves), intended for their small i-Light? It has a rear fitting with a clear opening of about 100 mm and it isn't likely to be expensive. It would be very simple to modify it to be fitted onto Lee lens adapters - it almost fits without modification. Living in a grip truck has its advantages.

Best,
Helen

[darr]

Darr,

I received three issues of the magazine from the publisher and in all three, the reproductions clearly show the difference. The printing process is an imperfect one and is often subject to variation, so I won't dispute that your issue doesn't reveal much of a difference. The attached files might better demonstrate what I am talking about in the article. Look at the detail inside the darkest cavity of the stump and also the rocks just below that area. Also the fence in the upper right.

As far as my contraption, what can I say? Perhaps I've been watching too many McGyver(sp)? re-runs.

Thank you for uploading your examples as the one on the left looks different from what my copy shows which looks more like the one on the right.

Best,
Darr

[Henry Ambrose]

Great idea Robert!

Helen,

I have a little 3" barn door for a small fresnel that I was thinking about using but the 4" one you mention sounds better. I am thinking of mounting that 4" barndoor on a mount similar to the Lee system base which is sort of a big step up ring I think. Let me know what you work out.

[MJSfoto1956]

There's a long-ish thread on the design of decent lens hoods here on APUG. It has differing opinions - one of the great advantages of the net over printed material. It also contains formulae and a diagram or two.

This endlessly long thread also exemplifies what is WRONG with the web. An editorial cleanup of the thread would make it much easier to read and digest. In the end, this thread would be a better presented as a concise article -- hey! that gives me an idea...