hasselblad V retrofucus wides on p45

[adrian tyler]

hello, just a quick, simple enquiry, first time over on the forum...

i tested out a phase one p45 with a hasselblad swc 38mm camera and experienced some pretty heavy lens casts.

does anyone have experience using the p45 with the 40, 50 or 60 hasselblad lenses, do they suffer from the same "problem"

thanks very much.

adrian

http://www.adriantyler.net/

[Gary Yeowell]

Adrian,

I can only comment on the 40CFE IF and 60CFI which i use with a P20. The 60 is cast free as far as i can see, and the 40 shows some colour fringing around some backlit areas when shot wide open to f5.6, both are super sharp. Incidently fringing can also occur wide open with my 100 & 180 however it's hardly noticeable, and gone one stop down.

The 40 CFE IF (latest) is the only wideangle lens i have tried (apart from some Digitars) which can equal or better the biogon for sharpness and contrast. After testing the new 40mm against my superwide SWCM, i sold the superwide, with my only grievance being the extra distortion apparent in the 40mm, and the extra 2mm.

Gary.

[mtomalty]

Adrian

I'm going to assume you are inferring to magenta/green color shift that is occurring
across the image and not fringing or chromatic aberration as Garry is responding to.

If this is the case then I think (bear in mind I don't own a DB but use them regularly) that
you find this 'lens cast' evident,to varying degrees,in most wides (some have reported seeing it on
Hasselblad Apo Teles,as well) and near wides when using Phase backs.

There is a very simple 'fix' for this in Phases capOne software called,LCC correction.
This involves taking an exposure with a translucent white disc placed over the lens in the
situation where you anticipate the cast occurring.
You then open this file in C1 and neutralize the file using the LCC correction after which
you apply this correction to all images taken with the same lens.
Very quick and efficient once you run through it a couple of times.

These custom lens profiles are then stored within C1 and can be applied to images using the same
lens under similar conditions.

I have seen the color cast with the SWC,as you have, the Arcbody with 45mm and an
older V 50mm blad lens.
The presence of the cast,generally,diminishes with longer focal lengths

If you navigate your way to the Knowledge Base at PhaseOne.com you will find a much
cleared overview than I have provided here.

Mark

[Gary Yeowell]

After re-reading i think you are right Mark, in that Adrian is experiencing overall casts, and your fix is spot on, even though i have not experienced it with any of my lenses mentioned.

Gary.

[adrian tyler]

thnaks for the input, yes, i mean the yellow/green cast which appeared in the centre and changed towards the edges on my swc. i had assumed that this was due to the closeness of the lens to the sensor, hence the question on the retrofucus "wides" as the distance is further from the lens to sensor.

adrian