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The ALPA Log

Tech Info Contax 645 Lenses

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Tests, illustrations and facts...

January 13, 2016
Alpa Reflex Model 6b

Sometimes people cannot believe that exceptional glass on the right camera is still exceptional glass also after 16 years or so. Todays test with our Carl Zeiss T* Distagon 3.5/35 for Contax 645 on our ALPA 12 FPS with the new ALPA lens module for Contax 645 lenses together with a Phase One IQ180 digital back. Our cameras are built to last and help good stuff to survive.Please find here some sample shots as overview and also full resolution images plus illustrations of movements in the context of what is achievable with those lenses. All the test images were captured with a Phase One IQ180 digital back (80 MP resolution, pixel pitch 5.2 micron).CAUTION: Due to gusty wind there might be some blurry trees and bushes.Product Pages[/en/article/alpa-12-fps|ALPA 12 FPS][/en/article/fps-lens-module-contax-645-shift|ALPA 12 FPS Lens Module CONTAX 645 shift]SAMPLE A - Carl Zeiss T* Distagon 3.5/35 mmTaken with the IQ180 and 5 mm of rise (upwards shift). The gusty wind and day time made us capturing this at f8 and 1/4 sec @ ISO 35. This is a plain photograph and distance set to infinity. The 5 mm rise equal an image circle of 72 mm and therefore in the upper edges already beyond the official image circle. BTW: Yes, the sky was rather purplish that evening ;)

Download Sample A - Full Resolution JPG 71 MB - store it locally - best viewing experience in Photoshop and a 4k monitorSAMPLE B - Carl Zeiss T* Sonnar 2.8/140 mmTaken with the IQ180 and 5 mm of rise (upwards shift). The gusty wind and day time made us capturing this at f11 and 1/2 sec @ ISO 35. The full rez portion shows the University Zurich at a distance of approximatively 1.5 kilometers. BTW: Again a good sample of the low vibration of the ALPA 12 FPS together with a small pixel digital back. Also the all new IQ3 100 MP has similar sized pixels of 4.6 microns. Therefore no big issue for the FPS when used properly and with a sturdy tripod.

Download Sample B - Full Resolution JPG 8 MB - store it locally - best viewing experience in Photoshop and a 4k monitorILLUSTRATION - Image circle and movementsWhat do you see when using the full movement of 12 mm (in this case rise)? An illustration for understanding the nominal image circles of the Contax 645 lenses (70 mm) and what you can see. These are illustration graphs only. Full resolution samples will be added once the we find the time, better weather and an appropriate object ;)

Download illustration CZ T* Distagon 3.5/35 mmDownload illustration CZ T* Sonnar 2.8/140 mm