What to do with a 75mm Tominon.

[Wayne Crider]

While I know that the lens won't cover 4x5 at infinity, can anyone tell me what the lens will cover. 6x9, 2x3, 3x4? And at what magnification will it cover 4x5. I've got one in a Copal shutter and wouldn't mind doing some (maybe moody?) flower stuff with it just to utilize it, but it will require me taking a Crown carcass I have and putting it back together with some odd parts. I've also thought about adapting the shutter with a pinhole; So I'm open to any idea's. Some paper neg's might be fun.

[Dan Fromm]

According to Polaroid's documentation, the lens will cover 4x5 at magnifications >= 2:1 At infinity it will cover 6x6. I've tried one -- MP-4 flavor, in barrel, not the CU-5 flavor in shutter -- at distance on a 2x3 Graphic, wouldn't use it. There are much better macro (magnification >= 1:1) lenses. If you want an inexpensive 75 mm enlarging lens that works very well as a macro lens, look for a 75/4.5 Enlarging Ektar.

I'm not sure which shutter your lens is in, Copal Press #0 with considerably restricted maximum aperture is the most likely. If you want to repurpose the shutter, extract the cells and measure the tube length. I've never had a 75/4.5 Tominon in shutter so haven't done the exercise, but I have done it with two 127/4.7 Tominons, both ex-CU-5, in shutter. Those shutters' tubes were 20.5 mm long; the #0 standard is 20.0. And their diaphragms don't open to 30 mm, the #0 standard.

[Ian Greenhalgh]

The 75 in shutter is said to shoot very well on 2x3 at distance, unlike the mp-4 version in barrel. I haven't tried one but two people told me they use one as a wide on 2x3 with success.

[Dan Fromm]

Ian, f/4.5 tessar types -- the 75/4.5 MP-4 Tominon is a reversed tessar, I have no idea what the CU-4 75/4.5 is but its probably the same -- do well to cover 110% of their focal lengths. There's a lot of confusion between "illuminates" and "covers."

[Ian Greenhalgh]

Indeed there is Dan and without having tried it myself, I cant say whether the Tominon 75 in shutter covers fully or just illuminates. The Mamiya 2.8/80 from a TLR I adapted to use on my Century 23 is a tessar too and it almost covers, just the very corners are dark, it's close enough to be usable. As Wayne already has one, no harm in trying it, but I would want to see more evidence it did cover if I was going to buy one specifically to use as a wide on 2x3. There is a steady supply of them on ebay in europe and I keep thinking of taking one as I need a #1 shutter and it's the cheapest way to get one, but the issues with restricted aperture put me off.

[Jim Galli]

Burn ants. After some practice on the ants, perhaps you could set the paper negs on fire. Other than that, they're pretty much useless.

[Ian Greenhalgh]

If the aperture opened the full way, they'd be a great source of #1s. :(

[JohnJ]

At infinity the Tominon 75/4.5 is extremely sharp in the centre (superb) but it seems to have field curvature, or something, and the sharpness falls off dramatically towards the edges, even when shot on 35mm, which is the only way I've used it. For this reason I think it is useless at infinity however it might be good as a portrait lens. At macro distances or close range it's very sharp across the frame (at 35mm). This may not help the OP, ie not relevant to larger formats, but this lens does have it's uses other than burning ants, sorry Jim.

[Ian Greenhalgh]

That's interesting John, are you talking about the barrel mount version that fits onto a #1 or the version that's mounted in a #1?

[Wayne Crider]

I measured the throat of the aperture and it's 13.86mm. Barrel length is 20.37mm.

I could probably mount a pinhole in it. At least I have a board for it.

Btw, F4.5-45.

[JohnJ]

That's interesting John, are you talking about the barrel mount version that fits onto a #1 or the version that's mounted in a #1?

I'm talking about the lens designed for use with the MP4, ie that fits onto the front of the shutter. I guess it's the barrel mount to use your terminology but often they are (wrongly) described as enlarging lenses.