LF lens idea - opinions sought.

[Farside]

Browsing through the listings for vintage lenses I came across a couple that were mounted on shutter boxes...

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...which neatly confirmed an idea I'd had for fitting lenses to the front of a 5x4 view camera.
One thing I have plenty of is shutters - they're in a drawer, nicely parcelled up in old camera bodies, with 'Praktica' written on them. It occurs to me that a stripped-down camera body can be fixed to a lens panel and provide a full-range shutter with a lens attached to the front of it via the M42 thread. No big deal to modify the lens via an adapter mount.
I also recall somebody saying that many of the 135mm M42 lenses were capable of covering at least Medium Format if the rear lens group is removed and happily enough 135mm is the standard (or close) lens for 5x4, and I have some hopes that some of them might cover 5x4.
I might be totally wasting my time with this, but it's easy enough to jury-rig something up without doing any manufacturing at all.

Opinions?

[A G Photography]

The lens could maybe cover a medium format circle (which is a helluva smaller than 4x5 anyway) but the shutter curtains of your poor Prakticas open just for the 35mm size, alas you'll end up with a very nice expensive 4x5 film plate with a 35mm image on it.

Just use a nice black hat in front of barrel lens if you want to test the thrill to shoot without shutters... it works if you're working with f64 aperture.

[Farside]

[Sevo]

Not entirely impossible, but a 35mm size curtain shutter with its 24mm on the narrow side will be very, very much on the small side for LF. A #0, the smallest leaf shutter you'll find on some wide or very dim LF lenses, is barely narrower and placed near the nodal point within the lens, while a before- or behind-the-lens shutter is in a worse location and must be quite a bit bigger.

A 135mm for 35mm with the FP shutter in its regular location will only cover 24x36mm (pretty exactly so, that's why it is called a focal plane shutter). While some 135mm Tessar types have enough coverage for 9x12cm, you'd need a 9x12cm FP shutter to exploit that, or shift the shutter much closer to the lens nodal point - in all likelyhood beyond the rear element, where you'd run into a huge number of expensive problems rebuilding the shutter and lens so that you get a working inter-lens curtain shutter.

Even if you can get the shutter to work with the entire body removed, it would be limited in its useability as a before- or behind-the-lens shutter to few lenses - for BTL use on wides as well as for any fastish lens, you'd need a much larger shutter, which leaves you with a shutter only useable on ancient f/8 or f/11 lenses in the 150-210mm range. Given that older sinar/Copal BTL shutters (with 80mm diameter) usually go for about 80-120€, it will hardly be worth while - having a new case machined for that shutter might be more expensive.

[Farside]

Damn! Looks like it's f:64 and a black hat, then.

[Farside]

Holding a Pentacon 135 ass-backwards in front of the GG screen of the Graphic View, I was suddenly confronted by a full focused image of the scene in front of me - at 5x4, too. The distance from the GG was ~12" - I didn't measure it. Also, the crappy Marep 200 does the same, but the flare issue with that lens might crop up again.

[kansalliskala]

Do you have any Kiev? Take the shutter apart and put it backwards so that the curtain is diretcly to the rear element of the lens? (It really works without any excess parts if some sort of rails are attached so upper curtain clicks to the lower.) So you have times from 1 to 1/1000 also. Just an idea .. no actual experience about lf lenses .. but seems more possible than Praktika (unless the shutter also comes totally free like Kiev? Was this the original idea .. must start reading these posts before answering .. )

[kansalliskala]

The shutter assembly on the right work as is (but curtains drop on the wrong place without guiding rails of some sort ..)

[Farside]

I since thought of using a Kiev 6 body as a shutter - just strip everything else off the body but the shutter mech and the lens mount, and even cut down the mount box to bring it back further.
Turns out I'm not the first to think of this, by a long way , but I haven't heard of anyone actually doing it.