Problem Using 28mm with HTS

[Mr.Gale]

I have a H4D50 and am having a problem using my 28mm with the HTS. The HTS works fine with my 100mm and the 28mm works fine when mounted to the camera. The problem I'm seeing is the exposure, when the lens is mounted to the camera the exposure might be 1/60 sec @ f11 but when I attache the 28mm to the HTS the exposure is 1 or 2 minutes at f11. Anyone have idea what's going on?
Thank,
Mr.Gale

[Hassilistic]

Hi Gale,

The HTS 1.5 was specifically designed for use with the HCD 4/28mm and HC 2.8/80mm lenses, and these should be seen as the primary choice for maximum performance.  But unlike large format bellows and lens boards and other mechanical Tilt/Shift mechanisms, here their are 6 lens elements in 5 groups and as such there will be several changes (I apologise If I stated the obvious, just trying to provide information relevant to the issue):

- Firmware compatibility - in your case [H4D-40/50 camera (.hbf)2.1.0 / sensor unit (.CIM) R332] minimum or latest
- You will have a Focal length conversion factor of 1.5x, and an Aperture reduction -1.3 stops, which will transform your f4/28mm into f6,3/45 mm .. this will definitely translate into a different exposure altogether.  Like wise your hC 2,8/80 mm is now 4,5/128 mm.
- autofocus / focus confirmation (disabled)

That said, once you have taken all of that into account, recalibrate , re-measure, and re-expose, this tool is the envy of all medium format manufacturers for its ease of use, accuracy, and versatility.

PS. Be sure to create a Camera Profile if you haven't already done so just for the HTS to re-allocate the Mirror Lock-up botton elsewhere for ease of accessibility.

Hope this helps.

[Miller]

It may have to do with the coupling between lens - HTS - camera. I sometimes see the same behavior from this combination on my H3DII.
Also, sometimes the lens isn't recognized at all. Then turning the lens a little bit helps.

[Mr.Gale]

Thanks for the help guys. I cleaned the contacts on everything and that seemed to do it, I plan on using it in the field next week so I'll find out for sure if it is fixed. Now the only thing I need to do is figure out how to focus it.
Thanks again,
Gale