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Flexbody and CFV

A

asterpics

New Member
Hi.
This is my first post here but I read your questions and answers every day from quite some time to date. I wish to say thank you all of you for your competence, kindness and helpfull words for everyone.

Now my little (or big) problem.
After some doubts I got a almost new CFV39 for my Hasselblad gear and I am very happy for the results because everything works perfectly as aspected with each lens and accessories. The files are great and almost no focus problem at all (well, after some training!).
Just a little problem (or a big one) with the Flexbody connected as suggested with flash sync cable from the lens to the back. When I use the faster shutter speeds (1/125, 1/250, 1/500) I get a magenta cast on the whole frame; with slower shutter speeds the shoots are chromatically perfect. This happens with all my lenses and with different settings in the Time exposure menu on the CFV back. I did many test with different sync cables, different shutter release cables, two steps shoot, one step shoot, different camera setting in the CFV menu.... Alway the same results.
Any suggestion and help would be much appreciated.
Thanks in advance. Angelo.
 
I guess your settings are incorrect.

Make sure You set the cameramodel to flashsync and the shutterspeed to <1/8 sec.

Then it should work fine. Mine does.

If not, I suggest you contact your local Hasselblad service point.
 
Eksund,
thanks for your quick replay.
As I wrote (and following the instruction manual), I set camera model to flash sync and shutter speed <1/8 as normal operating mode with the flexbody and CFV back, but the result is always the same. I get a magenta cast only when I use 1/125, 1/250 or 1/500 shutter speed on the lens, otherwise no problem at all. I perceive that is a sync problem from lens and back but I am not able to solve it, and I am waiting a solution from my Hasselblad dealer too. As I stated, the back is almost new and so are the original cables i got with it from the previous owner.
Thanks again for your interest and help.
Angelo
 
Hello Angelo,

Welcome here at Hasselbladinfo forum.

Do not forget to post the solution of the problem you have with the flexbody.
It sound like an interesting one!



Paul
 
Well, well. One final tip.
(I had to try myself).

When you release the cable shutter, you must be careful to do it in two steps.
1. halfway in, you hear a click (thats when the shutter close)
2. then release the shutter (a lighter click) and after the picture taken, the lens will remained closed until you wind up again.

It will give you disscolored missexposed pictures otherwise.

Sorry for not remembering this when I answered you the first time.


If you try it out, without the back attached, you´ll se what happens.



This construction is done to make it possible to remove the light protection plate from an ordinary A-type film-magasin. You have to do that when the shutter/lens is closed. Then You fire Your shutter and reattach the lightprotector shield.

In the digital world, the CFV will activate after the first click and on the second register the light thru the lens. Done to fast - and you get mess.


It´s hard for a swedish bloke to communicate technical stuff, but I hope You understand.
 
@ Paul
thank you for your welcome. I hope to solve the problem.

@ Eksund
Thank you very much for your detailed explanation, but that is the exact procedure I follow for every shoot from the beginning with the same result: magenta cast when I shoot with shutter speed from 1/125 to 1/500.
Today I spoke with a technician in a store and he is shure that the problem comes from the shutter cable release. Im not really convinced about that. Anyway I did some other tests a few minutes ago with different shutter cables release without success. Any Idea?
Angelo
 
Angelo

I´m out of ideas.

The only thing I can ask, is if You are sure about cable, function? correct connection? connected at the right place? and that kind of thing. I am sure You would hear if your optics are out of order. But I guess You already checkad that.

If the back is working properly on a HB 500, it should work properly on the flexbody as well. Unless there is a fault in the shuttermechanism on the flexbody. You should be able to se if it work propelry if you do the proper procedure without the digital back connected.
 
Eksund,
thanks again for your quick reply.
Yes, I checked all sort of things you mentioned. The sync cable is the right one, the shoot procedure is correct, the connection is right, and all the shots with shutter speed of 1/60 and slower are perfect... Moreover the back works flawlessy with the 503CW and all my lenses...
Surely it is a little or big mystery!
Angelo
 
@ Polypal

Yes, I know but how?

Anyway, this morning I had a fool idea: shoot some tests with my 503CW+CFVback in flashsync mode setting, using the sync cable to connect the lens to the back (as I usually do with the flexbody). In this way the activation of the back comes from the sync cable instead of mechanical shutter release of the body.
Well, the result is the same: magenta cast from 1/125 to 1/500; no cast with 1/60 and slower.
I repeated the test in normal mode, i.e. setting the back in 500 mode, without the sync cable, and using the normal shutter release from the 503 body. Result: no cast in any frame till 1/500.
My conclusion (at the moment): the problem comes from the sync cable, the one that connect the lens to the back. Am I wrong? Any suggestion is welcome!
Angelo
 
Hello Angelo,


Your local Hasselblad representative or the Hasselblad service department in Sweden can shed some light on this problem.

My hunch is this has someting to do with synchronising of the back and the shutter of the lens.




Paul
 
asterpics said:
@ Polypal

Yes, I know but how?

Anyway, this morning I had a fool idea: shoot some tests with my 503CW+CFVback in flashsync mode setting, using the sync cable to connect the lens to the back (as I usually do with the flexbody). In this way the activation of the back comes from the sync cable instead of mechanical shutter release of the body.
Well, the result is the same: magenta cast from 1/125 to 1/500; no cast with 1/60 and slower.
I repeated the test in normal mode, i.e. setting the back in 500 mode, without the sync cable, and using the normal shutter release from the 503 body. Result: no cast in any frame till 1/500.
My conclusion (at the moment): the problem comes from the sync cable, the one that connect the lens to the back. Am I wrong? Any suggestion is welcome!
Angelo
Click to expand...

Your sync cable is NOT defect .
The issue you experience is due to fact , that some digital backs need a "wake up" before they can take a shot . The CFV backs are such backs .
This wake up signal is given by a little plunger on the rear of the camera body when using a 500 body for example .
Regard your flexbody as a technical camera or a view camera .
There is no mechanical way to wake up the back . So you must give your back that signal by using an extra sync cable which you plug into your back instead of the sync cable coming from the lens . That cable is not needed here . As extra sync cable you can use HASSELBLAD cable release H , part number 3043370 .
I assume you use the FLEXBODY from a tripod .
The CFV Back setting should be set to flash sync and you should set the exposure for say 2 or 3 seconds regardless of the shutter speed you use with the lens .
Now , when shooting , release the cable release H first . That "wakes up" the CFV back and the little amber light at the rear of the back turns on . Then release the shutter with the cable release . Take care not to "pull" any of the two cables , because that might transfer mechanical vibration to the camera .
The 2 or 3 seconds setting depends how good and fast you can handle the two release cables . Needs a little bit of practice .
I use this method when shooting with my view and also technical camera + CFV16/CFV39 and I have no more trouble with a magenta cast at any shutter speed since .
 
@ jotloob

Thank you very much for your detailed explanation.

Please help me to clarify one point.

"...There is no mechanical way to wake up the back. So you must give your back that signal by using an extra sync cable which you plug into your back instead of the sync cable coming from the lens . That cable is not needed here. As extra sync cable you can use HASSELBLAD cable release H , part number 3043370..."

Well, I was following the instruction from the CFV user manual, where I read (about the flexbody) that must be used the flash input sync cable that came with the back to connect the lens to the back for the proper signal. I didn't know the need of an extra sync cable in place of the supplied one with the back. Thank you for the suggestion.

As a consequence, now the right procedure to shoot with the flexbody would be in three steps instead of two (as described in the manual): first, half press the cable release to close the shutter, second, press the suggested extra sync cable to wake up the back, third, press the cable release to actuate the shutter. Is it right?

Finally, please can you indicate me where to plug the extra sync cable, because I see at least three possibilities on the CFV back.

Thanks again for your patience and kindness.

Angelo
 
asterpics said:
@ jotloob

Thank you very much for your detailed explanation.

Please help me to clarify one point.

"...There is no mechanical way to wake up the back. So you must give your back that signal by using an extra sync cable which you plug into your back instead of the sync cable coming from the lens . That cable is not needed here. As extra sync cable you can use HASSELBLAD cable release H , part number 3043370..."

Well, I was following the instruction from the CFV user manual, where I read (about the flexbody) that must be used the flash input sync cable that came with the back to connect the lens to the back for the proper signal. I didn't know the need of an extra sync cable in place of the supplied one with the back. Thank you for the suggestion.

As a consequence, now the right procedure to shoot with the flexbody would be in three steps instead of two (as described in the manual): first, half press the cable release to close the shutter, second, press the suggested extra sync cable to wake up the back, third, press the cable release to actuate the shutter. Is it right?

Finally, please can you indicate me where to plug the extra sync cable, because I see at least three possibilities on the CFV back.

Thanks again for your patience and kindness.

Angelo
Click to expand...


Angelo

HASSELBLAD users guides are not of the finest . I often had trouble finding all required info . The descriptions are short . Often too short .
So I could never find any hint for the CFV backs , that they need a wakeup signal when used with a view camera or technical camera .

Now coming back to the FLEXBODY .
I do not own a FLEXBODY myself but was using one for a couple of times .
The setup I have given above is not described anywhere but is the only one which works a 100% successful .
For my given setup you do not need the sync cable from the lens to the back . But you use the H-release cable instead and plug it into the SYNC-IN hub , as you did with the sync cable from the lens . No other possibility anyway .

Your first step , to get the lens ready for shutter release , has to be done regardless of using a film back or a digital back .
Second step would now be , press the little button on the H cable release .
That "arms" the CFV for shooting , say : it wakes up the back .
The third step is shutter release . It is important that you release the shutter within the 2 or 3 or 5 seconds time window . The times are choosen by yourself , as mentioned before .
That is it .

The 905SWC shows a similar issue . The recommended proceedure sometimes works , sometimes not . It is also a mechanical issue .
Therefore , when I use my SWC (from the tripod) , I use my given setup as well . No magenta casts since .

The overall magenta cast is a result of a bad syncronizing .
That magenta cast should not be mistaken with a cyan color cast on the left side of your image and a magenta cast on the right side . That is a lens related issue .

I hope this helps . If you have more questions , just come back .

Regards . Jurgen .
 
Jurgen,

thanks for sharing with me your invaluable experience!!!

I agree with you about Hasselblad manuals; its a new lesson for the future.

I will experiment your precious hint in the next few days as soon as I get the cable release you mentioned.

Best regards.

Angelo
 
From the manual of CFV-39

Flash sync
For use with un-modified 200 series models (together with C-lenses in C-mode), a FlexBody or view cameras fitted with a Hasselblad adapter.
• Make a Flash sync setting.
• A Flash sync input cable should be used.
• All exposures times, including the B setting, function correctly without having to alter the “Exposure Time” setting.
• Do not use a winder at rapid sequence setting.

This somehow disagree with earlier statement in this thread.
"All exposures times, including the B setting, function correctly without having to alter the “Exposure Time” setting."
 
Hi,
to all kind people interested in my little problem with Flexbody and CFV.
After any suggestion I received, and some further readings on the web I discovered the real technical question at this link: http://www.alpa.ch/en/glossary/phot...elblad-imacon-digital-back-with-the-alpa.html

Now with few euro I got a simple generic 'electric' cable release to wake up the back before the shoot with every shutter speed I use on the lens. No more magenta cast. Surely it is a bit annoying a three steps solution for each shoot but no other way at the moment.
And, yes, the manual is not very clear in regard, or at least it is not applicable in each case.
Thanks and regards.
Angelo
 
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