Re: Process lens image circle nature
Quote:
Originally Posted by
erian
I am planning to buy my first large process lens and I am wondering how does various process lenses image circle behave. Is it quick cut off or more gradual fade?
I am considering something around 750-800mm range and I plan to use it for portraiture (i.e. 1:1).
My LOMO O-2 600mm, a dyalite type, covers 41º in the specs but it illuminates around 90º, with increasing softness when going beyond the specified coverage circle.
Illumination circle of APO-Nikkors are also reportedly very big: https://www.largeformatphotography.i...ll=1#post56941
So for your application they may work, as you may have the corners in the out of focus, still you will have fall-off in the outer illumination boundary.
Re: Process lens image circle nature
Quote:
Originally Posted by
erian
I plan to build a camera obscura. The one where you can walk in. I plan to focus by moving the back inside the camera. I am thinking to use large photo paper and by large I mean really large like 1 meter by 60 cm or similar.
Cool! Vacuum frame? That would also be cool, but a bit of extra work. Have fun!
Re: Process lens image circle nature
Quote:
Originally Posted by
Pere Casals
My LOMO O-2 600mm, a dyalite type, covers 41º in the specs but it illuminates around 90º, with increasing softness when going beyond the specified coverage circle.
Illumination circle of APO-Nikkors are also reportedly very big:
https://www.largeformatphotography.i...ll=1#post56941
So for your application they may work, as you may have the corners in the out of focus, still you will have fall-off in the outer illumination boundary.
Nice, this is exactly what I was looking for.
Does anybody know this about Ronars and Artars?
Re: Process lens image circle nature
Quote:
Originally Posted by
Vaughn
Cool! Vacuum frame? That would also be cool, but a bit of extra work. Have fun!
I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).
Re: Process lens image circle nature
One week!
,
Use what you got, no vacuum, tape it up, use longest LF lens you have, use a hat for a shutter as paper is very low ISO, like 2 to 5 ASA which is the same almost as ISO.
If it's a family pic, do it after they all fall asleep and are not moving. The exposure may be very long.
No lens, use a pinhole and even longer exposure, Go here, https://www.mrpinhole.com/
Post the results here no matter what it looks like.
Repeat yearly.
Merry Christmas!
Out
Quote:
Originally Posted by
erian
I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).
Re: Process lens image circle nature
Quote:
Originally Posted by
erian
I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).
For a temporary camera, I'd just use low stick spray adhesive on the back of the paper.
Re: Process lens image circle nature
Quote:
Originally Posted by
erian
this about Ronars and Artars?
Ronars and Artars are also dyalites, with similar behaviour.
Re: Process lens image circle nature
Quote:
Originally Posted by
Pere Casals
Ronars and Artars are also dyalites, with similar behaviour.
How about Apo Gerogons?
Re: Process lens image circle nature
Quote:
Originally Posted by
Bob Salomon
How about Apo Gerogons?
If you'd read this discussion from the beginning you'd know that the longest Apo-Gerogon is too short for the OP's project.
Re: Process lens image circle nature
Quote:
Originally Posted by
Pere Casals
Ronars and Artars are also dyalites, with similar behaviour.
There are dialyte type Apo-Nikkors, too.