Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: locpham on January 04, 2010, 03:01:22 am

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: locpham on January 04, 2010, 03:01:22 am

This might seem like a stupid question but does anyone know if this would work.  I have the Pentax 645 FA 35mm lens, which has been a great lens.  I have a Sinar Hy6 body with 75Lv back.  Given that a there isn't anything wider than a 40mm for the Hy6 format, I was wondering if there was the possibility of converting the pentax 645 35mm to work on the Rollei.  The Digital sensor isn't even a full 645 size, so this should work, right?  

Any thoughts or recommendations as to how or where this might be done would be much appreciated.

Loc

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: Wim van Velzen on January 04, 2010, 04:41:43 am

Unfortunately you can't. There is no shutter in the lens, which is required for the Rollei, and you wouldn't be able to focus to infinity because of the longer distance between lens and film/sensor with the Rollei.

You can stitch with the 40mm though (I do so quite a lot), although not really feasable with people photography.

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: Graham Mitchell on January 04, 2010, 08:11:24 am

Unfortunately Wim is right. You could however use your digital back on another camera with a wide lens (one of the pluses of the adapter system).

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: locpham on January 04, 2010, 12:08:51 pm

Crap.  I totally forgot about the in lens shutter of the Rollei.  I guess that settles that.

Thanks for the replies, guys.

Loc

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: EricWHiss on January 04, 2010, 01:29:20 pm

Loc,

Yeah won't work for the above reasons, BUT.....

You can use "alternative lenses" on the 6008's.  If you just stick a lens on the front you can shoot pictures with a fixed exposure of approx 1/60 or something like that. Why? Because the secondary baffle behind the mirror blocks most of the light and this pops up prior to the shot with the mirror.  Note that there may be some light leaks on some bodies.  Anyone know if the Hy6/AFi works similarly?

Eric

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: Gigi on January 05, 2010, 04:59:44 pm

Some might have the 30mm Rollei fisheye available. Eric (!) has used some software to straighten it out - rather remarkably so. Worth considering, even if it seems a bit off the wall.

Title: Converting a Pentax 645 FA 35mm to Rollei
Post by: locpham on January 05, 2010, 06:32:40 pm

I actually had an adapter made to mount the pentax lens to a sinar lenboard.  With the use of a sinar P2, auto aperture shutter, and a sinar 75Lv back, I should be able to use lens.  I just received the rear adapter for the digital back so I have yet to use this set up, but hopefully, it should work.

I was just hoping there was an easier method without having to pull out or carry along the 4x5 every time.