Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-03-2011, 01:59 AM   #1
Site Supporter
aliasant's Avatar

Join Date: Feb 2010
Location: Stockholm
Photos: Gallery | Albums
Posts: 634
Can the K5 control a Synchro-Compur shutter like this?

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
 

Last edited by aliasant; 06-03-2011 at 03:24 AM.
06-03-2011, 03:01 AM   #2
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
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.

Last edited by Digitalis; 06-03-2011 at 03:14 AM.
06-03-2011, 03:16 AM   #3
Site Supporter
aliasant's Avatar

Join Date: Feb 2010
Location: Stockholm
Photos: Gallery | Albums
Posts: 634
Original Poster
QuoteOriginally posted by Digitalis Quote
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
06-03-2011, 03:25 AM   #4
Senior Member




Join Date: Jul 2009
Location: Thornbury, England
Photos: Gallery
Posts: 181
How about if use the bulb setting and release the lens shutter using an old style remote?

06-03-2011, 03:29 AM   #5
Site Supporter
aliasant's Avatar

Join Date: Feb 2010
Location: Stockholm
Photos: Gallery | Albums
Posts: 634
Original Poster
QuoteOriginally posted by Graham V Quote
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?
06-03-2011, 03:45 AM   #6
Senior Member




Join Date: Jul 2009
Location: Thornbury, England
Photos: Gallery
Posts: 181
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
06-03-2011, 03:49 AM   #7
Senior Member
Kim C's Avatar

Join Date: Dec 2006
Location: Lincoln, UK
Photos: Gallery
Posts: 229
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
06-03-2011, 04:02 AM   #8
Pentaxian




Join Date: Dec 2007
Location: Prague
Photos: Gallery
Posts: 1,198
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.

06-03-2011, 04:12 AM   #9
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
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.
06-03-2011, 04:53 AM   #10
Forum Member




Join Date: Oct 2009
Location: New York
Photos: Gallery
Posts: 66
QuoteOriginally posted by aliasant Quote
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.

QuoteOriginally posted by aliasant Quote
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
06-03-2011, 05:08 AM   #11
Senior Member
Kim C's Avatar

Join Date: Dec 2006
Location: Lincoln, UK
Photos: Gallery
Posts: 229
The OP was asking about using it on bellows

Kim

QuoteOriginally posted by vparseval Quote
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
06-03-2011, 06:03 AM   #12
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by RioRico Quote
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.

Last edited by Digitalis; 06-03-2011 at 06:28 AM.
06-03-2011, 06:10 AM   #13
Forum Member




Join Date: Oct 2009
Location: New York
Photos: Gallery
Posts: 66
QuoteOriginally posted by Kim C Quote
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.
06-03-2011, 06:20 AM   #14
Pentaxian
Ratmagiclady's Avatar

Join Date: Nov 2008
Location: GA
Photos: Gallery | Albums
Posts: 13,464
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.

Last edited by Ratmagiclady; 06-03-2011 at 06:38 AM.
06-03-2011, 06:39 AM   #15
Site Supporter
aliasant's Avatar

Join Date: Feb 2010
Location: Stockholm
Photos: Gallery | Albums
Posts: 634
Original Poster
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.

Last edited by aliasant; 06-03-2011 at 06:48 AM.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
contact, control, flash, focus, k-mount, k5, pentax, pentax lens, shutter, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need help! Super Program's NOT working shutter control. HermanLee Pentax Film SLR Discussion 6 03-18-2012 08:52 PM
Remote Shutter Control KidLogic Pentax DSLR Discussion 8 11-30-2010 07:59 AM
P30T, shutter will not reliably stay open on bulb with cable shutter control. skid2964 Pentax Film SLR Discussion 6 06-09-2008 08:04 AM
Pentax Synchro X Input benjikan Pentax DSLR Discussion 9 02-17-2007 04:14 PM



All times are GMT -7. The time now is 07:57 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top