H-mount adapter plate does not fit. Suggestions?

[torger]

So I got my H4D-50 and was about to attach the back to my Linhof Techno via the H-mount adapter plate I've used successfully with my H-mount Aptus.

Well, the H4D-50 did not fit:-(. It's very hard to figure out where it collides, but I have a theory. The safety button on top of the back is colliding with the small metal housing that holds the attach button in the adapter. This collision is not what causes the back not fit as a direct cause (it would not be an as distinctive metal-to-metal clap-stop as it is now, as the button is spring-loaded), but my theory is that the contact forces the back into a low position which makes the pin or the light trap to collide making it impossible to get into position.

My adapter plate is quite old (Phase One H101), and I'm thinking maybe that Hasselblad safety button did not exist on older backs (it does not exist on my Aptus by the way) meaning that the housing on the adapter plate worked before, but not with the newer backs. Is that right?

I've attached an image of the back, and of the adapter plate with the housing. I've started sanding down the critical area but I need to get a better tool tomorrow to finish the job. Before doing that I thought I'd ask here and see if anyone has any feedback.

[NickT]

I think your analysis is correct. I have a feeling too that the safety catch on the Hasselblads has changed over the years and this could be part of the problem.

[bdp]

Even if you grind that enough to clip on, don't you still need access to the safety catch to detach the back? Or does the blue button on the adapter do it?

Ben

[torger]

Even if you grind that enough to clip on, don't you still need access to the safety catch to detach the back? Or does the blue button on the adapter do it?

Good point... would not be nice to get it on there and then not be able to detatch it

It will be possible to access the safety catch though, but I need to make enough space so I can actually move it too.

[torger]

Problem solved. Sanding down the blue button housing to fit the safety catch button was enough. Now it sits without any jiggle at all. Problem is that I will need that fishing line trick to be able to detach it, but as I don't have any lens for my H4D body I won't be needing to do that often

[ErikKaffehr]

Hi,

Great news! I hope you enjoy your new back!

Best regards
Erik

Problem solved. Sanding down the blue button housing to fit the safety catch button was enough. Now it sits without any jiggle at all. Problem is that I will need that fishing line trick to be able to detach it, but as I don't have any lens for my H4D body I won't be needing to do that often

[torger]

Hi,

Great news! I hope you enjoy your new back!

Best regards
Erik

Thanks. I'll do plenty testing the coming time and see if it's for me. It's likely that I'll keep it, but not 100% sure. I do like my Aptus and the H4D-50 needs to prove itself.

It did not start too well because the files is not working in my favourite raw converter RawTherapee, which is kind of strange because most other Hassy files work. I'm trying to figure out why and make a patch. Seems like it could be a black level thing. Meanwhile I'll try to get used to Phocus, also have Lightroom as a backup.

[torger]

Adding some summarizing info here for reference if someone stumbles across the same issue later on:

• The problem is well-known, and it has been raised several times to the manufacturer but they haven't listened, so the design is probably not going to change
• H5D backs have the safety-catch on the side so the problem does not apply to those backs. I think the H4D-60 also have it to the side, not sure, but H3D and H4D backs have it centered and are affected
• Linhof Studio can provide a special tool to get grip of the safety catch button so the back becomes easier to detach from the plate
• Having to sand down the detach button housing on the adapter plate like I did is not always necessary, but if it is it's easy to do with a basic Dremel, and you only need to remove 0.2mm or so.