Noob question on Caltar 90mm f8
Hello, I just got one off ebay and it has a pentagon shaped aperture. I've never seen that in other formats. Is this normal for this lens? I also got a 180mm Sironar N which I was hoping to compare against, but it has a hexagon aperture. Appreciate any input on this. Thank you, Jesse
Re: Noob question on Caltar 90mm f8
Welcome!
Compare Bokeh wide open and stopped down
Re: Noob question on Caltar 90mm f8
Thank you, and thank you for your reply. I'll do that, hopefully it's normal for this lens.
Re: Noob question on Caltar 90mm f8
Normal for that brand of shutter, and many other shutters in all formats.
Re: Noob question on Caltar 90mm f8
Re: Noob question on Caltar 90mm f8
What Brian said. Many small- and medium-format lenses have five-bladed diaphragms, and some shutters for view camera lenses do as well. For example, I have an old 90mm f/8 Super-Angulon in Compur 00 that has a five-bladed diaphragm. What shutter is your lens mounted in?
Re: Noob question on Caltar 90mm f8
@Oren Grad. Thanks. It's in a Copal N0.0. I forgot that the shutter is separate:rolleyes:
Re: Noob question on Caltar 90mm f8
If you would be so kind, what is the full marking on the lens?
Re: Noob question on Caltar 90mm f8
Five bladed iris in the shutter is common and typical for a shutter of this size..
Would a five bladed iris for a wide angle LF view camera lens be significant, most likely no. This is due to the way most LF wide angle images are made which is majority of the image in "sharp" perceived focus. Out of focus rendition and in to out of focus rendition ala "Bokeh". Majority of these wide angle LF view camera lenses are optimized at f16, negating the value of a really round iris.
~Five bladed pentagon shaped iris on a wide angle LF view camera lens, use it in creative/expressive image making with narray-A-care.~
In the case of normal to longer than normal focal lengths, a really round iris can and does make a Significant difference if out of focus rendition and in to out of focus rendition is valued.
Majority of lenses using this shutter size have a five bladed iris, including Hazzelblad-Zeiss CF lenses with Prontor shutters (renders pentagon shaped out of focus items) and many others.
If out of focus and in to out of focus rendition is an important aspect of the image to be made, Choosing/using an non modern plasmat lens design like Tessar, Dialyte (APO artar, APO ronar, APO nikkor), Heilar, Dagor, in a non-modern shutter like older compur, compound, Ilex or in barrel with a really round iris will go a significant ways to aid in rounder-smoother out of focus rendition and in to out of focus rendition.
Completely depends on what the image goals and intent is, this drives lens choice then camera needed to properly support the requirements of the lens.
Bernice
Re: Noob question on Caltar 90mm f8
Related to this discussion - many Nikon lenses in Copal shutters came with 5-blade irises. Then at some point they had 7-blade irises instead. These were denoted with an "S" in a circle on the shutter. Nikon's lenses also often had 7-bladed irises. Related? I don't know, and neither do I know if it was requested by Nikon or just done by Copal.
I have a 90mm f/8 with 7-blade and 120mm f/8 with 5-blade.