Just for fun:Inexpensive long portrait lens for 8x10?

[Ed K.]

I've been frustrated in my attempts to find anything around 24-30 inch focal length for a portrait lens, and not happy with the prices portrait lenses are fetching these days. I also like to experiment with lenses that have a lot of aberations, but in a nice way, again for portrait.

So, thinking hey - big, completly round aperature...uncoated...reasonable sharpness in the center...some soft flares around highlights. Bingo - a Coke bottle bottom? Well, not quite - a Tiffen Diopter Set!! Looks like a +2 gives around 800mm focal length and a nice 62mm opening, which can be stopped down if desired by taping a piece of black paper to the back with a hole cut in it. I guess the small 62mm is about f12.5 or so, no? Anyway, I taped the lens onto a lensboard and racked a Sinar P out to about 3 feet - looks wonderful on the ground glass - just about the qualities I was looking for, and well, I was about to toss that diopter in the junk bin. Hmmm, an LF portrait lens that is sharper, more sophisticated and faster than a pinhole, in a decent focal length, and with a retail value of about a buck-fifty. I noticed that reading glasses could be used to make a nice soft-focus stereo image too. I'll be shooting a test in the next day or two to capture the nifty creamy image on the ground glass. I like the combination of pretty good sharpness but blooming highlights a lot. I'd bet a good quality closeup lens adapter (a coated doublet +2 or +3) would make a better lens with less blooming, but that wouldn't be as fun. Talk about creamy bokeh though - smooth, soft circles.

The only trouble is that I'll have to get a nice big coffee can and then paint it up to look like an old fashioned lens. Hmmm, have to try that with a 6" diameter diopter from a surplus store.

Has anyone else experimented with off the wall lenses like diopters, magnifying glasses, and other goodies as taking lenses? Lenses made from water between panes of glasss/plastic? Got any other good ones to try?

[David Karp]

I think John Siskin wrote an article in View Camera not too long ago about making your own LF lens out of old parts. Sort of like McGyver. That might be worth looking into.

If you read the article and have questions, he would probably be glad to talk to you about this. He has a studio in the S.F. Valley. He is a nice guy.

[Brian C. Miller]

I noticed that reading glasses could be used to make a nice soft-focus stereo image too.

If you do that, could you also put the nose and moustache on the lesboard too? I'd love to see a photo of that!

[Ole Tjugen]

The diopter number is the focal length in fractions of a meter, so a +2 would be a 500mm lens.

500mm / 62mm diameter gives f:8, or close enough.

[Jim Galli]

Symmetrically opposed Diopters act the same as other lenses so 2 #2's back to back should give you about 300mm and even faster right Ole? I've played with diopters cobbled onto a normal Rapid Rectilinear with fun results. IOW take a 12 or 15" RR and take the front group off and replace with a diopter. You get a very fast shorter lens with some marvelous aberations.

[Struan Gray]

If you can live with the colour fringing, fresnel lenses can be a nice combination of funky and fast.

[Ernest Purdum]

I noticed a lens at www.surplusshed.com that might be useful for someone playing this sort of game. It is a coated positive meniscus 115mm in diameter with a 383mm focal length. Stock number PL1141, $22.00. No, I don't have a connection to Surplus Shed other than having bought a few items from them.

The major problem, of course, is that without achromatizing getting correct focus is difficult in black and white and color results can be weird.

[Ed K.]

The diopter number is the focal length in fractions of a meter, so a +2 would be a 500mm lens.

500mm / 62mm diameter gives f:8, or close enough.

Ole - thanks for the useful fact! It was difficult to judge because I focused it to a distance of 10 feet from the subject, which required about 3/4 of what a two bellows set could do on a P. I'll have to try the +3 then. Also, the lensboard I used has a bright silver edge in the hole, which forms the iris and stops it down a tad - that could be giving some of the effect I observed and liked ( the halo ).

[Ole Tjugen]

Symmetrically opposed Diopters act the same as other lenses so 2 #2's back to back should give you about 300mm and even faster right Ole?

Just add the numbers: 2+2 = 4, so you get a 250mm combined lens - or close enough for all practical purposes.

That's the advantage of using diopter numbers.

[Michael Heald]

Hello! I've been thinking about this and I have a suggestion. A two inch f 12 telescope objective might be just the ticket. Often these achromats give superb quality at infinity (mine does!). They are multicoated and close focusing induces spherical aberration, since the lens is optimized for infinity. As I remember it, many portrait lenses use spherical aberration for the desired effect.
These two inch telescopes can be had on EBay for peanuts, maybe $20 or $30. I've got one and I think I'll give it a try once I get an 8x10 that can accommodate it! Best regards.

Mike