I have been using a HasseCVF39 digital back with 200 series and 500 series cameras for the last few months and have obtained some exceptional results. Definitely the CVF39 back has brought the V series into the digital age.
This month I started to use the digital back on a large format camera. All seemed to be going well but occasionally I got a dud image. After a bit of experimentation I managed to repeat the set of circumstances that produced the dud image. I am wondering if anyone on this forum has come across a similar problem. Would appreciate some advice on how I can narrow down or solve this problem. It could be user error ( am I doing something wrong ? ) could be hardware error or even a software/firmware problem?
The problem only occurs when photographing a very high dynamic range scene.
Using large format lens connected to the back with a sync cable.
The highlights are blown by 1/3 of a stop
This is with a fuji 125mm LF lens 1/60sec F8 Iso 50
The digital back is set to use Flash Sync
If we look at the detail
There is a slight magenta cast to the image. Also very high luminance noise ( even at ISO 50 !! )
In comparison if we look at the same scene photographed with a 200 series camera with a 100CF lens at 1/60sec F8 Iso 50
The digital back is set to use 200 Series Sync
The image has no observable luminance noise and no colour cast.
The complete files are here for comparison
I have tried with several large format lens and after some time I can produce the same dud image with each lens.
The factors to make this happen seem to be:-
Very high dynamic range scene, large areas of sunshine and shadows in the scene.
Use of a sync cable between lens and digital back
I looked in the Hasselblad manual and it says there is a shutter delay menu setting which is a corrective feature which adjusts the time a little to ensure the image is read from the sensor. There is a picture of the menu and setting in the manual. Unfortunately on the actual digital back the setting is not there in the menu system. ( firmware – 256 – the latest version)
Any advice on how I can narrow down or solve this issue appreciated.