The dark side of manual shutters

[cunim]

I am using Rodenstock HR90 and 40 lenses on technical and view cameras with a Hasselblad 50MP back.  These lenses are mounted in Copal 0 shutters.  In addition to my own two lenses, I have tried numerous other Copal-Rodenstocks from the 28 to a 120 (can't remember exactly but about there).

With all of these lenses I get the same problem:

1.  The image appears in Phocus in both the thumbnail and browser window.
2.  About 1/2 sec later the image is overwritten with black.  The black is actually data, and appears identical to an image of a closed shutter.

This appears to be lens-dependent.  My HR90, for example, does this with about 30% of images.  The 40 is about 10%.  Other lenses have varied from 50% to almost none.

HUSA tells me that this is a known problem.  "It is a known issue with some manual shutters, for example Copal shutters, that they do not give a correct “shutter close” sync signal for the digital back to pick up. This often means that you will experience a double sync trigger signal to the back and actually have an additional black exposure after the intended exposure. This has to do with the behavior of the shutter and is not related to the digital back."

I have no idea what I woulld do to correct this.  Anyone solved it?  I wonder if some backs are more sensitive to this than others.

[CBarrett]

What?!!!!  I own 11 lenses in Copal shutters and have never seen this issue on Phase backs.... is it limited to the 'Blad back?

-CB

[JonathanBenoit]

I am using Rodenstock HR90 and 40 lenses on technical and view cameras with a Hasselblad 50MP back.  These lenses are mounted in Copal 0 shutters.  In addition to my own two lenses, I have tried numerous other Copal-Rodenstocks from the 28 to a 120 (can't remember exactly but about there).

With all of these lenses I get the same problem:

1.  The image appears in Phocus in both the thumbnail and browser window.
2.  About 1/2 sec later the image is overwritten with black.  The black is actually data, and appears identical to an image of a closed shutter.

This appears to be lens-dependent.  My HR90, for example, does this with about 30% of images.  The 40 is about 10%.  Other lenses have varied from 50% to almost none.

HUSA tells me that this is a known problem.  "It is a known issue with some manual shutters, for example Copal shutters, that they do not give a correct “shutter close” sync signal for the digital back to pick up. This often means that you will experience a double sync trigger signal to the back and actually have an additional black exposure after the intended exposure. This has to do with the behavior of the shutter and is not related to the digital back."

I have no idea what I woulld do to correct this.  Anyone solved it?  I wonder if some backs are more sensitive to this than others.

Are you sure its not because of a lack of sufficient power to the back? I haven't heard of your specific problem before and you would think it would be an issue with Phase as well if its a problem with the copal shutter. How are you powering your back?

[Doug Peterson]

What?!!!!  I own 11 lenses in Copal shutters and have never seen this issue on Phase backs.... is it limited to the 'Blad back?

No idea either, but I've never seen this specific issue (black frame due to issue with shutter timing) with any phase back.

edit: not trying to be snide here - all systems, including phase, have problems - only putting in my experience here in hopes it can help the OP isolate and solve his problem.

[Dick Roadnight]

1.  The image appears in Phocus in both the thumbnail and browser window.
2.  About 1/2 sec later the image is overwritten with black.  The black is actually data, and appears identical to an image of a closed shutter.

I have not used my Hasselblad 50 much with copal shutters, but I have not experienced this problem.

Do you only get this problem in Phocus?

Are pictures taken with a Hasselblad camera OK?

Are you using the latest version of Phocus and the latest firmware for your back?

Is the file size normal? ¿Could it be two image files without an "end of file" after the first one?

Can you view the .fff files from other programs?

Phocus is a one layer program, so it could not be another image in another layer.

Have you tried working tethered, card reader, firewire...?

Have you tried to look at the pictures on another computer?

[JonathanBenoit]

Hasselblad doesn't want to admit any problems with their camera/backs. Their passing the blame to the lens manufacturers.
I own an H3DII. The biggest problem I have with Hasselblad is their lack of a tethered view camera powering solution. A simple battery pack independent from the firewire needs to happen. I'm not sure why this hasnt been addressed. If the mac firewire port puts out 7watts and the back needs 10watts, you can assume their will be problems.

[cunim]

Sorry for not giving more details in the original post.  I don`t want to get into Hassy-bashing and, for the record, I am very fond of my Hasselblad optics.  This is a specific issue with manual shutter interfacing when tethered under Phocus, and I was just wondering if it is happening only to me.

Assume I have swapped sync and firewire cables, am computer and software savvy, have the latest of everything, excellent clean power to the back, pictures taken with the camera are fine, everything normal except that the camera sometimes acquires a second image into a closed shutter, about a half second after displaying the first image.  Unfortunately, it overwrites the first image with the second.

Appears that this does not happen to other people, whether on Phase or HB backs.  It is either some sort of Phocus-computer interaction specific to my system (W7-64, Dell Studio XPS i7, Sonnet xpresscard firewire, Unibran driver, Tekkeon battery), or something wrong in the back.  I really hate that ``or`` part.

[ced]

Normally your back is expecting to be connected to one type of camera when you put it on a technical camera be sure that the right kind of camera is selected in the software when tethered, it is not on a hasselblad anymore when using the copal shutter...
Try different shutter speeds to be sure as sometimes certain backs have difficulty with too high shutter speeds.

[Fritzer]

In my experience, mechanical (leaf) shutters can sometimes have synching issues.

All my lenses have Copal shutters, most size 0 , and I'm getting heavily distorted (not black) images every other 100 shots or so; this is with a Leaf Aptus 75 and LC software . Reconnecting the back always helps.

However, on one shoot, I was using a rented Sinar with the Sinar shutter system, and that particular shutter distorted every shot taken at 1/4 s and longer (using my own trusty laptop, changing cables, power sources for the back and whatnot).

Changing the shutter fortunately solved the problem, and later discussion with people more knowledgable than I led me to believe the issue has indeed been related to synching the digital signal.

Photographers I know and myself are using manual shutters in every back/camera/lens/software combination imaginable, without a glitch, so I assume it is most likely your back is faulty; I'm very sure Copal shutters per se can not be blamed , and you seem to have ruled out other possible sources.

[pixjohn]

I just shot with an H4-50 with the Hasselblad Reps and had the same issue on a Cambo Wide DS. Every image produced a 2nd black image. They had no clue why, but thought testing with a 1 sync cable release from the Kapture Group might be a good start? I am doing another test and they said they would get the cable release for the shoot.


Its not you its a real problem.

[cunim]

I just shot with an H4-50 with the Hasselblad Reps and had the same issue on a Cambo Wide DS. Every image produced a 2nd black image. They had no clue why, but thought testing with a 1 sync cable release from the Kapture Group might be a good start? I am doing another test and they said they would get the cable release for the shoot.


Its not you its a real problem.

Pixjohn, great to hear I am not alone.  Alpa has very kindly sent me some suggestions for a workaround, which I will try as soon as I get my hands on an H cord.  Basically, they fire the back from the H cord and then open the shutter while the back is exposing.  I'll report back on whether it works.

[seanconboyphotogenics]

Normally your back is expecting to be connected to one type of camera when you put it on a technical camera be sure that the right kind of camera is selected in the software when tethered, it is not on a hasselblad anymore when using the copal shutter...
Try different shutter speeds to be sure as sometimes certain backs have difficulty with too high shutter speeds.

Hi i shoot hasselblad 50mp on linhof techno and copal shutters i get the black frame occasionally but always in addtion to the image i have just taken it never overwrites the image.i shoot mostly to macbook pro,iam on latest software and firmware,i must stress with me it only happens now and again.very happy with my back ,camera and lenses .regrds
sean

[eddysmit]

I think this is a mechanical problem of the shutter.
If the contact in the shutter has some chatter, it can give 2 closed contacts due to bounsing of the contact, or maybe a dirty contact. Of course the shutter is closed when  it starts taking the second picture...
In good software, a chatter limit and chatter period can be set.

[Rod.Klukas]

I've never seen his problem with Leaf backs either.
Shot several different Rodenstock and Schneider lenses
with Copal shutters with no occurence.
As someone suggested, it could be a power problem...
Rod

[Ray R]

I think I have a similar problem with a Mamiya RB  lens, not entirely black, but possibly a double exposure/movement and only at slower shutter speeds. I have 2 of the lenses and the other on is fine, I had assumed that there was a problem with the shutter on the lens that has the problem.

[cunim]

There is no doubt that this double image behavior is an interaction between the Copal and the H series back.  My issue is whether my specific back is hypercritical, or whether all H backs do this.  I get black images with all the Copal lenses I have tried (about half a dozen now).  These are all new Rodenstocks so it is not that they have become faulty.  This is the way they are and the back needs to deal with them.  I have noticed that some lenses are much worse than others, which must have something to do with the shutter adjustment.

I have just gotten a loaner 50MP back from my very helpful local dealer.  I will work with that for a couple of days to see if it is as sensitive as my own back is.  If yes, Hasselblad has a design problem in dealing with Copals.  If no, my own back needs adustment.  I hope it is the latter.

Hasselblad is trying to help and have asked if I could loan them a lens to duplicate the problem.  I am reluctant to send my lovely Alpa Rodenstock 90 HR (worst black image behavior) for torture testing so let's see what happens with the loaner back first.

[cunim]

I have now tested another 50MP back with my Rodenstock 40 and 90 HR lenses in Alpa mounts.  Both of them still give me black images, with about 10% of the 90mm images being black and a smaller proportion of the 40mm images.  I have now tested about a half dozen lenses on two backs.  

I am officially stumped.  No idea what to do next.  Hasselblad says it is a shutter problem.  I agree, but it is a problem with all of them.  Do we adapt the camera so that it tolerates shutter imperfections or do we try to make all the Copals perfect?  Hmm, that answer seems easy to me.  

I do intend to try working with Rollei shutters to see what little foibles they have.  My (faint) hope is that they are reliabile.

[JonathanBenoit]

I have now tested another 50MP back with my Rodenstock 40 and 90 HR lenses in Alpa mounts.  Both of them still give me black images, with about 10% of the 90mm images being black and a smaller proportion of the 40mm images.  I have now tested about a half dozen lenses on two backs.  

I am officially stumped.  No idea what to do next.  Hasselblad says it is a shutter problem.  I agree, but it is a problem with all of them.  Do we adapt the camera so that it tolerates shutter imperfections or do we try to make all the Copals perfect?  Hmm, that answer seems easy to me.  

I do intend to try working with Rollei shutters to see what little foibles they have.  My (faint) hope is that they are reliabile.

I know you think this isnt a power issue, but could you describe your setup?

[pixjohn]

Its a Hasselblad issue! I got the same issue with my 24xl on a copal shutter.

I am shooting with a H4-50 back on wed, The Hasselblad rep says he will have a special cable release that should solve the problem? Its a wait and see what happens. As a perspective owner Hasselblad needs to step up and talk about the problem. Its not a killer don't buy but its a pain I don't want to deal with.

[schaubild]

It could be that there is some issue with your shutter. I would try if it triggers a normal flash, if this works fine, I'd concentrate on the back.

No matter what some support guys try to tell you about having a faulty shutter, it has been acknowledged by Hasselblad that there are some timing issues in their backs. This has been known for years, fingerpointing to the Copal is just much more convenient.

http://www.alpa.ch/en/glossary/photographi...h-the-alpa.html


Addendum: I called Alpa regarding this issue to ask if the situation has changed. This is obviously not the case. But they added some more information about the required procedures to make HB backs work with Copal shutters.

It makes me really wonder why other tech camera manufacturers don't provide this kind of information to their customers?