[aliasant]

I would like to control the shutter on this from my Pentax K5.
Is that possible using that electrical flash input on the shutter?
If not what is that contact on the shutter for?

Added info:
I want to use this lens or something similar on an m42 bellows with my Pentax K-5.
I need to be able to use a flash. I dont want to (primarily anyways) use this for longer exposures.
I want to be able to focus wide open and then that the lens closes + the flash goes off when I press the shutter on my K-5.
K-5s flashspeed is 1/180 and it has a flash output contact. Would have been great if I could use the Compurs higher sync speeds.
I guess I could use B on the Pentax and then open up the Synchro shutter manually but that will be hard to do while trying to take a picture at mag ratio 1:1 or more.

Main objective is to be able to focus wide open and close down to whatever f-stop I set the shutter to from my pentax.

Attached Images

 

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Last edited by aliasant; 06-03-2011 at 03:24 AM.

[Digitalis]

in short: no. The K5 cannot use compur leaf shutter lenses, the contact I think you are referring to on the lens is the PC synch plug on the lens - which works exactly the same way as the PC-synch connector on the K5.


Nice lens BTW.

[aliasant]

in short: no. The K5 cannot use compur leaf shutter lenses, the contact I think you are referring to on the lens is the PC synch plug on the lens - which works exactly the same way as the PC-synch connector on the K5.


Nice lens BTW.

I dont own that lens but Im thinking of bying on it if I can find a way to use it.

I have no experience with the PC-Synch contact either. No idea what it does. I thought it simply sent out a low voltage pulse from the K5? I then hoped that the shutter could receive that low pulse and close down the shutter but it seems it isnt as simple as that

[Graham V]

How about if use the bulb setting and release the lens shutter using an old style remote?

[aliasant]

How about if use the bulb setting and release the lens shutter using an old style remote?

The more I understand the more I think thats the way to do it.
But it might be hard.
I shoot a lot of macro and often at ranges 1:1 - 2:1 so I need to be very very steady. I dont use a tripod and depend on flash.

Maybe I can use a trigger cord that I place somewere convinient and pressing that will release/open up the shutter and that will send a signal to my flash?
Would that then work with the shutters higher speeds?

[Graham V]

Macro! Blimey I thought I make my life difficult at times

Can't really help with the flash but it sounds like it should work

[Kim C]

Connect the flash to the compur shutter. Set the shutter on the K5 to bulb (if you can). Then fire the compur shutter. The compur will fire the flash.

Kim

[elho_cid]

I don't think that DSLR controlling this lens is the best idea. I'd rather build a simple device that controls both the lens and the camera shutter. Could fire the strobes as well, with single click.

[RioRico]

Why fire the Compur shutter? Why not just use the lens as a lens? Set it to B, block the shutter open, and use shutter and flash on the camera. The camera shutter may be a bit more accurate.

[vparseval]

The more I understand the more I think thats the way to do it.
But it might be hard.
I shoot a lot of macro and often at ranges 1:1 - 2:1 so I need to be very very steady. I dont use a tripod and depend on flash.

How do you intend to mount the lens to the body? It's a large-format lens and they don't come with any provision to focus them (which is why all LF cameras use bellows). If you want to shoot a 1:1 macro, the lens needs to be 300mm away from the sensor. 450mm is needed if you want to achieve 2:1.

Maybe I can use a trigger cord that I place somewere convinient and pressing that will release/open up the shutter and that will send a signal to my flash? Would that then work with the shutters higher speeds?

Depends. This will work if you are basically building your own LF camera. The camera body will be set to bulk. You open its shutter while the lens is still closed (all LF lenses have a switch for that) and then you can use a cable release to open the lens and the flash will be fired if it's connected to the sync port of the lens. Then you close the camera's shutter. This will work with all shutter speeds the lens has to offer because it is a leaf-shutter.

Needless to say, for this to work you need to make sure that the chamber between the shutter of the camera and the lens is absolutely light-tight. Your best bet might be to buy a cheap used LF camera (a Sinar F1 maybe) and fine a way to mount your camera to the rear standard where the focusing screen would normally be.

But honestly, I don't quite see the point of this whole exercise. Really the only advantage you get from a setup like this is a higher flash sync and the typical movement that a LF camera offers (rise, swing, tilt).

Cheers,
Tassilo

[Kim C]

The OP was asking about using it on bellows

Kim

How do you intend to mount the lens to the body? It's a large-format lens and they don't come with any provision to focus them (which is why all LF cameras use bellows). If you want to shoot a 1:1 macro, the lens needs to be 300mm away from the sensor. 450mm is needed if you want to achieve 2:1.



Cheers,
Tassilo

[Digitalis]

Why fire the Compur shutter? Why not just use the lens as a lens?

because a Compur shutter can synch with flash at all speeds. the lens the OP is talking about, a rather classic Voigtlander APO-Lanthar 150mm lens uses a type of leaf shutter that is quite common in large format cameras. There are three basic types of Leaf shutters large format cameras use - Compur, Prontor and copal shutters - they are all leaf shutters that do the same thing but it is how they are used and their capabilities that makes them different.

*Some of those older lanthar lenses sometimes contain lanthanum in the glass which was a substitute for radioactive thorium. A curious property of lanthanum glass is that it is highly transmissive in the Infared spectrum. Also beware that due to the fact that in their elemental forms Lanthanum and Actinium - (a radioactive Beta emitter) are difficult to separate and because of this many lanthar lenses are in fact radioactive. Actinium has a half-life of 22.1 years - considering the age of the lens I think you should be in the clear.

[vparseval]

The OP was asking about using it on bellows

Oddly enough, I missed that. How long is that bellows unit though? It's most likely not long enough for macro works.

[Ratmagiclady]

You could open the K-5's shutter on Bulb and then use the leaf shutter to trigger the flash and make the exposure, or you could put the leaf-shutter on T (Which is like Bulb, only it locks open) and connect your flash unit to the K5 and fire more or less normally.

There is no way to make these lenses do 'auto stopdown:' they weren't made for SLRs, and they're a number of decades too early for that feature, anyway.

If you trigger the flash with the lens-shutter, you may need to make some allowances for the fact that the shutter's flash synch was designed for nothing more advanced than flashbulbs: which would do a bit of a slower burn than electronic ones. (I seem to remember successfully using one on an old Crown Graphic with that shutter, but I'm not recalling the details of what we could get away with: they open quickly, leaf shutters, but.... You know, I can't recall actually having any problems. I can't test, now because what I have now that's like it has no flash synch.) I'm not sure you'd really want to do that, apart from perhaps using Live View to replicate the focusing-by-ground-glass experience.


But, yes, with a bellows, it can be done:




As for the length of the bellows, no problem, actually, it seems to be in quite a moderate range, and adding extension tubes is actually kind of something that makes things fit up better. I might even advise a lighter and cheaper setup off Ebay, since the lovely old Pentax one shown here is kind of a beast to try and hand-hold.

Anyway, I haven't tested the limits of getting-very-macro, but if you order some plain M42 extension tubes when you get your M42-m39 adapter, extension probably won't be the limiting factor. When you see those old cameras in the movies, they tend to show them extended a lot more for normal shooting than they really would be: they just hand em out as props to extras who don't know how they'd really be used.

[aliasant]

Wow.

Lots of answers and great info.

First things first.
When I first started thinking about that flash connection on old synchro shutters I wondered if it would be possible to build something for MEDIUM FORMAT
I forgot that this extremely sexy Voigtländer is Large Format

I have bought ( but not received yet) 1 Ikoflex + one similar unknown brand + a Voigtländer medium format. I wanted to try those shutters and lenses to see if I could use them on bellows with flash.

Using this specific LF lens would probably be hard unless I use
Camera -> "sewerpipe" ->Bellows -> lens in shutter.

Medium format is the way to go but the shutter thing would be the same wouldnt it?

I think I want to try the K5 on Bulb, a shutterrelease cable attached somewere handy on the bellows that opens the shutter which then triggers the flash.

As some pointed out those shutters were made for slower burning flashes so im not sure the shutter will open up when the flash goes off.

Another "slightly" crazyer idea might be to build an electronic remote that also fires a pin Shutter release cable thing + a small delay compensation setting but that is nothing I can build.
Something for an entrepreneur maybe?
A wireless little thing that can hook up to a Shutter Release cable AND send a signal to the Pentax k5 to release the shutter. Synced but with a small knob that adjusts a delay for either the SR cable or the DSLR signal.