View Full Version : Will a Rapid Rectilinear swirl?

Neil Purling
1-Feb-2009, 15:43
I have just received my 6" f5.8 R&J Beck Biplanat back from SK Grimes.
It sits in a Copal #1, so I have the full range of speeds and flash sync.
I wondered if I would get the swirly effect often seen with Petzvals if I use this lens wide-open? I was not able to explore the wider apertures of this lens before the re-mount.
I can't remember what defect it is that causes the swirlies in a lens, or if the lens must be undersized for the format.

1-Feb-2009, 16:19
Mine never has. And if it did, I'd probably get rid of it... yhat 'swirliness' makes me nauseous.

1-Feb-2009, 16:23
i am not sure about RR but i had a triplet once that swirled nicely. i was surprised. try it.

aim it at some highlights (i use the tops of trees so you can see the effect) and then begin to focus closer, watch the highlights to see if she is going to go. it helps to use it on a bigger than intended format as well.

keep us posted.


Neil Purling
1-Feb-2009, 23:16
You can see the effect on the GG screen, rather than upon inspection of the negative?
I wondered if I would need a much more simple lens, like a Petzval or a meniscus.

2-Feb-2009, 09:24
My B&L R.R. hasn't done it yet. I haven't aimed it at backlit foliage yet. I have a 50mm Nikkor lens that is famous/infamous for swirlies at f=1.4. Pinpoints of light through trees will do it. The more separation between subject and trees and pinpoints of light, the more pronounced the effect.

Gene McCluney
2-Feb-2009, 09:49
In general a Rapid Rectilinear design lens will not swirl. If you use one on a larger format than it was intended to cover, it will get soft at the edges, though

Jim Galli
2-Feb-2009, 10:27
A rapid rectilinear will swirl if you grasp it well below the center of gravity and use a little wrist action when you release. But that's no way to treat a Copal 1 shutter. Take it out first.

Neil Purling
2-Feb-2009, 14:50
I thought that I had seen something of the effect in a shot taken with an ex-Autographic B&L lens. It was in backlit foliage, but I cannot rule out the possibility of movement in the leaves & branches due to wind. That B&L does have interesting drop-off though.
Jim: Would you treat such fine machine work so carelessly? I will get around to testing the 6" Beck when the weather improves.