Used on an Alpa FPS and a 44x33mm sensor like the IQ 250 you get into the not-so-good part of the image circle too often. From about 3 or 4mm of shift f11 is better with the 17mm and 24mm.
The 17mm and 24mm need to be stopped down to f11 for better corner sharpness.
This will change of course if you have a 3-dimensional subject that needs more depth of field. Unshifted position: for a flat subject I would use all lenses at f8.I attach a compilation of crops from different parts of images with 10mm of vertical shift. I did a detailed comparison of the TS-Es (17mm, 24mm II, 90mm) and the Contax-Zeiss PC-Distagon 35mm on Luminous Landscape Forum (). Thanks so much, if anybody has any information, would be greatly appreciated!
The one difference that I am wondering between these two camera systems (presuming that both have suitable image circles to be used with the shift adapter), is whether the Hasselblad H lenses will flash sync at their maximum sync speed on the Alpa FPS (using the lenses leaf shutters), even when using full shift on the Alpa adapter? I noticed a similar post by "kimyeesan" and see that "chrismuc" has had access to a preproduction version of the Contax 645 shift adapter and these results look very impressive!! They obviously have a much larger image circle than 645 otherwise a "shift" adapter would be pointless.
I recently saw the Alpa Shift adapter for Hasselblad H lensesĪLPA of Switzerland - Manufacturers of remarkable cameras - Photokina 2014Īnd was wondering if anybody had information on the image circle of these lenses? Image Circle of Hasselblad H Lenses on Alpa FPS and shift adapter? Alpa plans to release it (and the Hasselblad H and Rollei Hy6 versions) within the next months. Also very useful with the Contax 645 shift adapter for the FPS. The total image circle of the 55 is much larger than the 35, but the sharp image circle is slightly smaller.
The series version of course will have the deeply black matt coatings which are standard for Alpa products.) This leads to internal reflexions/flare which reduces the contrast especially of the super-wide angle 35 mm lens and even reflected stripe patterns can be seen in the sky in the left upper corner of the image. (Comment: The pre-series Alpa Contax 645 shift adapter is completely anodized in black but lacks inside matt coating. At f16, the usable sharp image circle enlarges to about 80 mm (but of course the general sharpness is reduced slightly due to diffraction). Here I removed/reduced the geometrcial distortion of the single images first using the Alpa lens corrector plug-in for Photoshop before stiching them together. This time at f16 and camera and sensor in portrait orientation, four pictures stiched together (center, 12 mm right, 12 mm right + 12 mm up, 12 mm up).
I added a version of the same file reduced to IQ250 sensor size plus 12mm shift to all directions.Īs you can see, the image is perfectly sharp within +/- 12mm right/left OR up/down, just both together leaves the corners outside the total image circle.Įnclosed a second test image by the Contax 645 35f3.5. I added rulers to the images to better determine the sharp image circles and the total image circles.
This results in images 76mm wide and 52,5mm high (stiched sensor size) with about 150 MP resolution. All Contax 645 lenses work perfectly with the FPS, the camera recognizes the lens with its correct maximum aperture, the aperture can be choosen in the FPS menu (just like with Canon lenses using the FPS Canon EF mount), the aperture ring at the lens is out of function.įor my first tests I used f11 for all shots and auto-stitched in Photoshop CS6 always four pictures in landscape orientation after opening them in ACR and doing some basic adjustments (use equal color temperature, add some clarity, unsharp mask 100% 0,5 pixel, automatic reduction of chromatic aberation):* Sorry Kim I don't own (any longer) the 45-90. I did initial tests of several Contax 645 lenses from 35 mm to 210 mm but here to mention only the wide angle Distagons 35f3.5 and 55f3.5. Of course it has the latest firmware to control the aperture (and focus if required by the user!) of the Contax 645 lenses. The Contax 645 shift adapter is technically not yet the mass production version but the preliminary version they showed at Photokina 2014. Alpa was so nice to borrow me their Contax 645 version of the mount for the FPS which allows 12mm shift movements in all directions (left/right and up/down independingly and simultanously) and I did tests with some lenses (all with IQ180).