645 75mm Leaf Shutter - bent tips?

glass · 04-21-2016, 06:42 AM

Two of my leaf shutter blades have slightly bent tips. I presume this is by design. The lowest blade tip bends downwards. However, it isn't the highest blade tip that bends upwards, but the 2nd highest blade. So it looks like the bent tip would catch/rub on the highest blade.

Would somebody with a 75mm LS lens please check and let me know if yours is the same? I'm concerned the lens may have been previously opened and the blades reassembled in the wrong order.

So just to clarify, my lens looking from the front and working anti-clockwise: Highest blade (straight tip), next blade (tip bent upwards), next blade (straight), next blade (straight), lowest blade (tip bent downwards).

Thanks.

wombat2go · 04-21-2016, 06:44 AM

I copy my reply here from you query on 645Z thread:

While I don't know for your lens, I can verify that on the old Super-Multi-Coated Takumar /6x7 1:2.8 90mm here, that the visible front leaf is "bent".

Same for a Copal "0" on a Super Angulon here. ( The former owner gave a discount for that, but I am sure it is part of the design of some of the Copal shutters.)

Read more at: https://www.pentaxforums.com/forums/48-pentax-medium-format/280273-pentax-645...#ixzz46T6gSjxA

Bob L · 04-21-2016, 08:38 AM

My LS 75 is the same as yours so I'm going to guess that it's perfectly normal.

Bob

glass · 04-21-2016, 11:24 AM

Originally posted by Bob L

My LS 75 is the same as yours so I'm going to guess that it's perfectly normal.

Bob

Thank you - glad to hear it as i'm loving the 75 LS and didn't want to return it unnecessarily.

texandrews · 04-22-2016, 10:14 AM

Originally posted by glass

Thank you - glad to hear it as i'm loving the 75 LS and didn't want to return it unnecessarily.

Yeah, it's a nice lens---although I'm having intermittent fire problems. Digitalis(I think maybe) mentioned a possible reason for this in a post somewhere----had to do with getting sticky when cold. I also think I need to send it in for servicing.

Tell me---do you have to tap your shutter button before actually firing to make sure the camera, lens/shutter, and flash are really communicating? I have found this to be true, and am wondering if this is the correct routine or a quirk of my particular camera....

glass · 04-23-2016, 04:07 PM

Originally posted by texandrews

Yeah, it's a nice lens---although I'm having intermittent fire problems. Digitalis(I think maybe) mentioned a possible reason for this in a post somewhere----had to do with getting sticky when cold. I also think I need to send it in for servicing.

Tell me---do you have to tap your shutter button before actually firing to make sure the camera, lens/shutter, and flash are really communicating? I have found this to be true, and am wondering if this is the correct routine or a quirk of my particular camera....

I'm not sure what you mean by 'tap the shutter button before actually firing'. Do you mean press it half way? Or fire a dummy shot before taking a proper shot?

Either way, no I don't need to on mine. I just cock the leaf shutter, ensure the Focal Plane (camera) shutter is 1/8s, then shoot as normal. The viewfinder stays black until I re-cock the lens shutter.

If I'm in Live View, then I need to exit Live View (which causes the lens shutter to fire), re-cock the lens shutter, then shoot.

texandrews · 04-24-2016, 04:08 AM

Originally posted by glass

I'm not sure what you mean by 'tap the shutter button before actually firing'. Do you mean press it half way?

Yes, that's what I mean. My camera recognizes that the LS lens is on there, says LS in the top LED finder and LCD screen----I don't have to manually set the speed to 1/8. But if I just press the shutter button after waiting for a moment or two between shots, and after a re-cock, I need to do a half press before I can get the lens to reliably fire my flash and use its own shutter as opposed to the camera's. It's as if the camera is in sleep mode and has to be woken up to re-establish communication with the lens.

That said, I think my lens needs servicing as it is less reliable the colder it gets.

glass · 04-25-2016, 02:31 AM

In LS mode, my leaf shutter does not work properly. 1/60s works, but any faster and 95% of the time I get a black frame, and 5% of the time I'll get a picture or a partial frame.

I've taped up one of the contacts as per this thread: https://www.pentaxforums.com/forums/48-pentax-medium-format/280273-pentax-645...y-success.html. Now my leaf shutter works reliably at all speeds, every time. Personally I think it is a firmware issue and not something physical that can be fixed by servicing.

04-21-2016, 06:42 AM	#1
glass Junior Member Join Date: Mar 2016 Posts: 37	645 75mm Leaf Shutter - bent tips? Two of my leaf shutter blades have slightly bent tips. I presume this is by design. The lowest blade tip bends downwards. However, it isn't the highest blade tip that bends upwards, but the 2nd highest blade. So it looks like the bent tip would catch/rub on the highest blade. Would somebody with a 75mm LS lens please check and let me know if yours is the same? I'm concerned the lens may have been previously opened and the blades reassembled in the wrong order. So just to clarify, my lens looking from the front and working anti-clockwise: Highest blade (straight tip), next blade (tip bent upwards), next blade (straight), next blade (straight), lowest blade (tip bent downwards). Thanks.

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04-21-2016, 06:44 AM	#2
wombat2go Veteran Member Join Date: Jan 2010 Location: Michigan Photos: Gallery Posts: 2,207	I copy my reply here from you query on 645Z thread: While I don't know for your lens, I can verify that on the old Super-Multi-Coated Takumar /6x7 1:2.8 90mm here, that the visible front leaf is "bent". Same for a Copal "0" on a Super Angulon here. ( The former owner gave a discount for that, but I am sure it is part of the design of some of the Copal shutters.) Read more at: https://www.pentaxforums.com/forums/48-pentax-medium-format/280273-pentax-645...#ixzz46T6gSjxA

04-21-2016, 08:38 AM	#3
Bob L Senior Member Join Date: Mar 2016 Location: La Vienne (86), France Posts: 223	My LS 75 is the same as yours so I'm going to guess that it's perfectly normal. Bob

04-21-2016, 11:24 AM	#4
glass Junior Member Join Date: Mar 2016 Posts: 37 Original Poster	Originally posted by Bob L My LS 75 is the same as yours so I'm going to guess that it's perfectly normal. Bob Thank you - glad to hear it as i'm loving the 75 LS and didn't want to return it unnecessarily.

04-22-2016, 10:14 AM	#5
texandrews Moderator Join Date: Apr 2014 Location: Baltimore Photos: Albums Posts: 3,397	Originally posted by glass Thank you - glad to hear it as i'm loving the 75 LS and didn't want to return it unnecessarily. Yeah, it's a nice lens---although I'm having intermittent fire problems. Digitalis(I think maybe) mentioned a possible reason for this in a post somewhere----had to do with getting sticky when cold. I also think I need to send it in for servicing. Tell me---do you have to tap your shutter button before actually firing to make sure the camera, lens/shutter, and flash are really communicating? I have found this to be true, and am wondering if this is the correct routine or a quirk of my particular camera....

04-23-2016, 04:07 PM	#6
glass Junior Member Join Date: Mar 2016 Posts: 37 Original Poster	Originally posted by texandrews Yeah, it's a nice lens---although I'm having intermittent fire problems. Digitalis(I think maybe) mentioned a possible reason for this in a post somewhere----had to do with getting sticky when cold. I also think I need to send it in for servicing. Tell me---do you have to tap your shutter button before actually firing to make sure the camera, lens/shutter, and flash are really communicating? I have found this to be true, and am wondering if this is the correct routine or a quirk of my particular camera.... I'm not sure what you mean by 'tap the shutter button before actually firing'. Do you mean press it half way? Or fire a dummy shot before taking a proper shot? Either way, no I don't need to on mine. I just cock the leaf shutter, ensure the Focal Plane (camera) shutter is 1/8s, then shoot as normal. The viewfinder stays black until I re-cock the lens shutter. If I'm in Live View, then I need to exit Live View (which causes the lens shutter to fire), re-cock the lens shutter, then shoot.

04-24-2016, 04:08 AM	#7
texandrews Moderator Join Date: Apr 2014 Location: Baltimore Photos: Albums Posts: 3,397	Originally posted by glass I'm not sure what you mean by 'tap the shutter button before actually firing'. Do you mean press it half way? Yes, that's what I mean. My camera recognizes that the LS lens is on there, says LS in the top LED finder and LCD screen----I don't have to manually set the speed to 1/8. But if I just press the shutter button after waiting for a moment or two between shots, and after a re-cock, I need to do a half press before I can get the lens to reliably fire my flash and use its own shutter as opposed to the camera's. It's as if the camera is in sleep mode and has to be woken up to re-establish communication with the lens. That said, I think my lens needs servicing as it is less reliable the colder it gets.

04-25-2016, 02:31 AM	#8
glass Junior Member Join Date: Mar 2016 Posts: 37 Original Poster	In LS mode, my leaf shutter does not work properly. 1/60s works, but any faster and 95% of the time I get a black frame, and 5% of the time I'll get a picture or a partial frame. I've taped up one of the contacts as per this thread: https://www.pentaxforums.com/forums/48-pentax-medium-format/280273-pentax-645...y-success.html. Now my leaf shutter works reliably at all speeds, every time. Personally I think it is a firmware issue and not something physical that can be fixed by servicing.