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Using Hasselblad 200-series with digital backs

BradleyGibson

New member
As requested from another thread:

Until the S2 was announced, the Hasselblad 200 (specifically the 203FE) was probably the best-specified camera system for the type of work I do. Coupled with the fact that I enjoyed my experiences shooting with a 500-series camera, the 200 made for a compelling platform.

Just one problem--poor digital support.

I didn't like the idea of sending the camera back to Sweden for the modification that they do which impacts ISO communication in some way with film backs.

And I didn't like the idea of being limited to the small, 16-megapixel CFV back that Hasselblad offers. With a CF39, or equivalent, I'd be interested, but for whatever reasons, Hasselblad chooses not to make their higher resolution offerings available for the 200-series.

So I started working on the problem and think I've come up with an idea to allow any digital back to work with the 200.

Backs will apparently work fine up to the camera's flash sync speed, 1/90s. Faster than this, the entire frame is not exposed at the same time, and the back will not see a full frame.

As most here are probably aware, the shutter is actually composed of two curtains. The first curtain travels across the frame, exposing the sensor to light. At some later point in time, the second curtain travels across the frame in the same direction, ending the exposure to light. During cocking, both curtains are returned to the opposite side of the frame, ready to start again.

My research shows that they sync signal given by the camera closes the circuit when the first curtain has finished travelling, and opens when the second curtain starts travelling.

If this is true, then the first curtain sync signal needs to be advanced by 11.1ms (1/90s--the time it takes for the shutter to travel the frame), and the second curtain sync needs to be retarded by 11.1ms. This will ensure that the back is recording during the period of time that any part of the frame is exposed, regardless of shutter speed.

Retarding the 2nd curtain signal is fairly straightforward, and can be done with a custom sync cable with some logic.

Advancing the 1st curtain signal is the difficult part, as only the camera knows when the shutter was pressed. So that means modifying the electronic behavior of the camera.

I am looking for electronic schematics for the 203FE which would allow me to do this more easily. If anyone knows where I can lay my hands on this, I'd appreciate a pointer!

In the end, I would need to use the custom cable technique to return the sync port to normal behavior (for use with strobes). But that would be a small price to pay to get the ability to use any digital back at any speed on the Hassy 203FE.

I do not yet understand the Phase wake-up architecture, but other brands of back should be just fine with this arrangement. The Phase might need a small extra bit of trickery to ensure it is ready at the right time, but this will require more research.

Hopefully that makes sense. If folks are interested in helping out with this project, please let me know. I won't clutter up the board with talk of hardware engineering (of which I only know enough to be dangerous), but I am working with some helpful people who do this for a living.

Electronic schematics of the Hasselblad 203FE would be very, very welcome. :)

Thanks, all,
Brad
 

yongfei

New member
Brad, I also salute you for trying to take over Hasselblad engineers' job:p
I know Hasselblad service center has the parts diagram, but not sure about electronic schematics.

Anyway, the easiest non-destructive approach would be to build a minimized electronic switch, and mount it on the accessory shoe. As my mechanical shutter test has already proved, this is basically an easy two-shot approach: flip on the switch first, and then fire the real shutter within a reasonable time (eg 1-5 sec)

So can you build or find a minized electronic timer? Hopefully with a 1-10 second adjustment - time for you to press the real shutter. Basically for every shot, you are really exposuring the back for 1 to 10 seconds (depending on your timer setting).
 

yongfei

New member
David, do you have any insider information on why Hasselblad didn't apply this CFV approach on all the other CF backs?
 
The hardware in the CFV was built especially for this purpose. We use a small sensor that reads the exposure 'armature'(?) that fires out the camera body when the exposure is triggered.

Due to the flexibility of the CF back (working with may different camera bodies) and the i-adapter system it isn't practical to build this into the CF range.

Hope that helps!

Best,


David
 

BradleyGibson

New member
It's an interesting idea, but I just can't imagine myself trying to shoot eagles, for example, controlling two shutters.

If my efforts at modification fail, I will have to look at other ideas, though, so I'll keep it in mind.

Thanks,
-Brad
Brad, I also salute you for trying to take over Hasselblad engineers' job:p
I know Hasselblad service center has the parts diagram, but not sure about electronic schematics.

Anyway, the easiest non-destructive approach would be to build a minimized electronic switch, and mount it on the accessory shoe. As my mechanical shutter test has already proved, this is basically an easy two-shot approach: flip on the switch first, and then fire the real shutter within a reasonable time (eg 1-5 sec)

So can you build or find a minized electronic timer? Hopefully with a 1-10 second adjustment - time for you to press the real shutter. Basically for every shot, you are really exposuring the back for 1 to 10 seconds (depending on your timer setting).
 

atanabe

Member
Brad,
Yes you can shoot with the 203FE and CFV with flash sync (cabled) but at 1/90th it is a little dicey as to the full exposure across the sensor. I have done this with the 2000FCW and found that if the CFV has been idle for a bit, the first exposure at 1/90th will be a little magenta (unsynced exposure) on the right edge of the frame. If you use a leaf shutter lens and flash sync with the leaf shutter you will not have an issue it is only with the non shuttered (F, FE) lenses and the focal plane shutter.

As far as getting the 203 FE modified, Hasselblad USA is right there in Redmond, WA and you can hand deliver the camera there and they take care of the paperwork. Hasselblad does have their act together on repair work, email confirmation of receipt of the item with expected return date, electronic warranty registration and confirmation of warranty.

The other option is to stick with a 500 series camera and have no problems with sync. If you go with a Phase or Leaf back you will need cables regardless of the body and I have been told that the 200-2000 series is not on the recommended list of cameras. I have gone through a lot of the pains in adapting my cameras, SWC, 501CM, 2000FCW so that they will be consistent in exposure with the CFV. Let me know if you would like to try the different combinations, I am located in downtown Seattle.

Regards,
Al
 

Stuart Richardson

Active member
Two things Brad -- when testing the adapter I got from you, the CFE lens I have worked fine at all apertures. The 110/2 FE at least does not work at ANY aperture, even below the sync speed. All the photos are streaky. This could just be my camera. For what it is worth, however, Kapture Group told me that their cable will work at all speeds with FE lenses on the 203FE. I would definitely prefer a cable-free solution as well (using my own Sinar back, not the CFV), but I think I am willing to use the cable.
 

Stuart Richardson

Active member
Oh, and I almost forgot. This may be a bit of stab to the heart, but the manual for the 203FE states that the camera does not send a sync signal above 1/90s. I am not sure why this is, but it is what is written in the manual. If this is the case, your effort probably will not bear fruit since it is dependent on the camera sending a sync signal at all speeds.

I guess the 203FE was too smart for its own good -- no sync signal over 1/90th means it's pretty obvious if you set the shutter speed wrong and use a flash -- there will be no flash fired, but that same "feature" is likely what cripples the camera for use with digital backs.
 

PeterA

Well-known member
Brad,
Yes you can shoot with the 203FE and CFV with flash sync (cabled) but at 1/90th it is a little dicey as to the full exposure across the sensor. I have done this with the 2000FCW and found that if the CFV has been idle for a bit, the first exposure at 1/90th will be a little magenta (unsynced exposure) on the right edge of the frame. If you use a leaf shutter lens and flash sync with the leaf shutter you will not have an issue it is only with the non shuttered (F, FE) lenses and the focal plane shutter.

As far as getting the 203 FE modified, Hasselblad USA is right there in Redmond, WA and you can hand deliver the camera there and they take care of the paperwork. Hasselblad does have their act together on repair work, email confirmation of receipt of the item with expected return date, electronic warranty registration and confirmation of warranty.

The other option is to stick with a 500 series camera and have no problems with sync. If you go with a Phase or Leaf back you will need cables regardless of the body and I have been told that the 200-2000 series is not on the recommended list of cameras. I have gone through a lot of the pains in adapting my cameras, SWC, 501CM, 2000FCW so that they will be consistent in exposure with the CFV. Let me know if you would like to try the different combinations, I am located in downtown Seattle.

Regards,
Al
That is interesting - I am using a CFV11 back on a Hasselbald modified 205TCC ( bought from Son) and have experienced no such issues with any of my F/FE lenses.
 

atanabe

Member
That is interesting - I am using a CFV11 back on a Hasselbald modified 205TCC ( bought from Son) and have experienced no such issues with any of my F/FE lenses.
If the camera (203 or 205) has been modified for the CFV back then there are no issues. Brad is working with a non modified 203.
 

BradleyGibson

New member
Hi, Atanbe,

I may take you up on that offer, thank you!

I'm in Woodinville, but am in Seattle at least a couple of times per week.

As for the CFV, in the original posting, I wrote "And I didn't like the idea of being limited to the small, 16-megapixel CFV back that Hasselblad offers."

If I can modify the camera so that this problem "goes away", then I can upgrade to the latest 50+ megapixel backs and enjoy life in the fast lane.

Speaking of speed, that's one of the reasons I prefer the FE glass to the CF(I/E) glass. The lack of central shutter buys an extra stop, which is sorely needed. Since I (almost) never shoot in the studio, flash sync speed is not much of a concern for me.

I may ping you to see the CFV in operation; I'll keep you posted on my little experiment once I begin.

Take care,
Brad


Brad,
Yes you can shoot with the 203FE and CFV with flash sync (cabled) but at 1/90th it is a little dicey as to the full exposure across the sensor. I have done this with the 2000FCW and found that if the CFV has been idle for a bit, the first exposure at 1/90th will be a little magenta (unsynced exposure) on the right edge of the frame. If you use a leaf shutter lens and flash sync with the leaf shutter you will not have an issue it is only with the non shuttered (F, FE) lenses and the focal plane shutter.

As far as getting the 203 FE modified, Hasselblad USA is right there in Redmond, WA and you can hand deliver the camera there and they take care of the paperwork. Hasselblad does have their act together on repair work, email confirmation of receipt of the item with expected return date, electronic warranty registration and confirmation of warranty.

The other option is to stick with a 500 series camera and have no problems with sync. If you go with a Phase or Leaf back you will need cables regardless of the body and I have been told that the 200-2000 series is not on the recommended list of cameras. I have gone through a lot of the pains in adapting my cameras, SWC, 501CM, 2000FCW so that they will be consistent in exposure with the CFV. Let me know if you would like to try the different combinations, I am located in downtown Seattle.

Regards,
Al
 

BradleyGibson

New member
Ouch.

Ok, that's a bit of a problem. Thanks for that, I was unaware.

Still, with my modification, every exposure will last at least 1/90th of a second regardless of shutter speed (at least as far as the sync signal is concerned). So there may yet be hope. Again, I'll have to open one up and see what's going on to remove/reprogram whatever logic is controlling sync signals now.

Thanks again, that's helpful. Painful, but helpful. :)

Oh, and I almost forgot. This may be a bit of stab to the heart, but the manual for the 203FE states that the camera does not send a sync signal above 1/90s. I am not sure why this is, but it is what is written in the manual. If this is the case, your effort probably will not bear fruit since it is dependent on the camera sending a sync signal at all speeds.

I guess the 203FE was too smart for its own good -- no sync signal over 1/90th means it's pretty obvious if you set the shutter speed wrong and use a flash -- there will be no flash fired, but that same "feature" is likely what cripples the camera for use with digital backs.
 

PeterA

Well-known member
Two things Brad -- when testing the adapter I got from you, the CFE lens I have worked fine at all apertures. The 110/2 FE at least does not work at ANY aperture, even below the sync speed. All the photos are streaky. This could just be my camera. For what it is worth, however, Kapture Group told me that their cable will work at all speeds with FE lenses on the 203FE. I would definitely prefer a cable-free solution as well (using my own Sinar back, not the CFV), but I think I am willing to use the cable.
Stuart are you saying that the Capture Group cable will allow for any digi back with V mount to be used with a 203 at any shutter speed?
 

Stuart Richardson

Active member
Peter, I am not sure about other backs. This was just from my conversation with capture group about my own situation. It sounds like it is universal though. Here is the conversation:

"For some reason the sync on the focal plane shutter on 200/2000 series cameras are not compatible with digital sensors. Our modified Oneshot cable provides a flash sync signal while you are depressing the cable release. For this to work properly you need to continue to depress the release as long as the shutter remains open. One this cable you do not even connect to the pc sync from the lens. The Oneshot starts and stops the expose just before and just after the shutter closes. This solution can be used at all shutter speeds.

Let me know if you need more information.

Keith"
"Hi Keith,

So does this mean that the 200 series will work with the Sinar back and FE lenses as long as I use your modified cable and hold down the release? That's what it sounds like."

"Yes, any of the lenses. Our cable bypasses any sync created on the body or lens.

Keith"
 

PeterA

Well-known member
Peter, I am not sure about other backs. This was just from my conversation with capture group about my own situation. It sounds like it is universal though. Here is the conversation:

"For some reason the sync on the focal plane shutter on 200/2000 series cameras are not compatible with digital sensors. Our modified Oneshot cable provides a flash sync signal while you are depressing the cable release. For this to work properly you need to continue to depress the release as long as the shutter remains open. One this cable you do not even connect to the pc sync from the lens. The Oneshot starts and stops the expose just before and just after the shutter closes. This solution can be used at all shutter speeds.

Let me know if you need more information.

Keith"
"Hi Keith,

So does this mean that the 200 series will work with the Sinar back and FE lenses as long as I use your modified cable and hold down the release? That's what it sounds like."

"Yes, any of the lenses. Our cable bypasses any sync created on the body or lens.

Keith"
Thanks Stuart.
 

yongfei

New member
>the Capture Group cable will allow for any digi back with V mount to be used with a 203 at any shutter speed?

Does it work on Phase back? I think it depends on how it will synch after the back has been waked up.

For other backs, the Kapture cable is basically equivalent to two switches in concept, as in my mechanical Copal shutter test: the first switch controls the theoretical exposure time (the duration you hold the cable release), the second switch triggers the shutter and makes the real exposure. "A real exposure within a nominal exposure". Quite clever design approach, but the price is high for this simple yet specialized item.
 
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David Klepacki

New member
I tried this cable method with the Hasselblad 203, and I was not happy with the results. Basically, the digital back is activated and an exposure is made for the duration that you depress the cable release. Typically, you cannot depress it fast than about 1/30, so that is about the exposure time that the back is actually making.

The other part of this cable controls the shutter release on the camera body. It is designed so that the shutter is triggered within the exposure window of the digital back. For example, you can release the shutter at its setting of 1/1000, and the scene will be exposed to the digital back within its longer activated window (typically about 1/30 as described above).

The flaw in the ointment is that this longer exposure time of the digital back is capturing the "blackness" of the camera body internals outside of the actual camera shutter's interval, and I found a great deal of extra noise in the photos that would normally not occur.

For FE lenses, I found it much easier to just mount them on a Contax 645. Although the waist level finder on the Contax is not as large, the resulting image quality is superior. OF course, you trade off the ability to auto stop-down the lens on the 203, for the electronic focus confirmation and higher shutter speeds of the Contax. Nowadays, the price of a Contax body is not too much more than the Kapture cable. I just think of the Contax camera as my "Hasselblad V 645", since I tend to use only the V lenses on it anyway.
 
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