Front cap wont work with filter...

[roguegeek]

I purchased an 80mm f2.8 C chrome lens a couple of weeks ago. It came with the original grey rear cap, but nothing else. Naturally, I rushed to order a grey front B50 lens cap and a B50 haze filter from KEH. The cap fits great. The filter fits great. Here's the problem. I can't use the cap when the filter is on. Coming from a world of EF and F-mounts, I just don't understand why this is.

Can someone give me some insight into this? Also, is there a front lens cap that will work on a B50 filter?

 

[roguegeek]

And now that I think about it a little more, does this mean I wont be able to use a filter and lens hood together at the same time either?

 

[polypal]

Early grey lens caps do not fit whenever a filter is fitted to B50 lenses.

Later CF/E/I style black lens caps use the inner bayonet and can be screwed into the filter.

The shade fits nicely on the external bayonet lips of the lens when the filter is fitted to the lens.

 

[roguegeek]

Early grey lens caps do not fit whenever a filter is fitted to B50 lenses.

Later CF/E/I style black lens caps use the inner bayonet and can be screwed into the filter.

So can I grab any black B50 Hasselblad lens cap or are there ones that will not fit like the grey caps?

 

[polypal]

So can I grab any black B50 Hasselblad lens cap or are there ones that will not fit like the grey caps?

It is not as simple as that.
You are after this lens cap:



Picture is from internet, could not find a better one because I am not at home.

This is the model that was later fitted to CF/E/i lenses as well.
Make sure you get one for B57 also called B50 mount.
Most of these caps are B60 for later lenses.
I am sure KEH can supply you the correct cap.
Also available from Chinese sellers at eBay.
These caps are being reproduced in China.