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
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