Petzval ... ????

[Erik Lund]

Now I got interested, too
I love blurry and bokeh capable lenses.
A quick search on eBay resulted in:
http://www.ebay.de/itm/Cyclop-1-5-85-Helios-40-2-M42-Portrait-Objektiv-bokeh-monster-Petzval-swirl-/261997564089?hash=item3d004590b9
It's not expensive but it's an M42 mount lens.
Wouldn't know how difficult it would be to modify for Nikon f-mount?

Buy it'! Even if it's just for the super cool name :* 
I'll put a F-mount on it no problem, I'm sure Bjørn will sell you a custom CPU to go
Should be possible to get infinity but yes who cares...

[Erik Lund]

Or we add a Nikon 1 mount as well, do this all the time with Bjørns lenses - Go for it!

[Jakov Minić]

Or we add a Nikon 1 mount as well, do this all the time with Bjørns lenses - Go for it!

You buy it then! 

[Erik Lund]

He he 

[Jakov Minić]

I ended up with your Heligon, and I see I'll end up with your Cyclop too ;P
You wanna share?

[Erik Lund]

This is the same lens AFAIK
http://www.ebay.de/itm/NEW-DESIGN-Helios-40-2-N-85-mm-f-1-5-MC-Lens-Nikon-bayonet-mounts-Brand-New-2015-/261994003613?hash=item3d000f3c9d

[Björn Carlén]

Here is an other New Petzval 85 shot. This time without any specular highlights. And this is about as close as it can focus, without any help.
Wealth.

[Jakov Minić]

This is the same lens AFAIK
http://www.ebay.de/itm/NEW-DESIGN-Helios-40-2-N-85-mm-f-1-5-MC-Lens-Nikon-bayonet-mounts-Brand-New-2015-/261994003613?hash=item3d000f3c9d

No good, it doesn't say Cyclop

Nice image Björn!

[Bjørn Rørslett]

Remove all aperture blades from the Helios, or epoxy the aperture at f/1.5 setting. Now you can have a Cyclop as well .....

[Björn Carlén]

The above image was shot totally open. I had left my aperture plates at home, so I put some black tape on the waterhouse slot, to avoid stray light, and used it like that. The biggest aperture plate is f/2,2 so presumingly this is the same. What do you say – could there be any downsides of shooting it in this manner?

[Erik Lund]

Yes , there can/will be a slight difference in rendering depending on where the light rays gets cut in the optical assembly.

A quick test to see this is to make a small square opening cut in a pice of cardboard and place it in front of the lens and the behind the lens.

Then look at the OOF rendering

[Erik Lund]

This is the same lens AFAIK
http://www.ebay.de/itm/NEW-DESIGN-Helios-40-2-N-85-mm-f-1-5-MC-Lens-Nikon-bayonet-mounts-Brand-New-2015-/261994003613?hash=item3d000f3c9d

No good, it doesn't say Cyclop

Nice image Björn!

He he 

[Bjørn Rørslett]

Apart from getting very short exposures, and short depth of field, I see no harm in using any lens at its widest aperture setting.

Mechanical vignetting can occur, though.

[Erik Lund]

yes and no.

The lens is f/2.2 and the largest aperture insert is f/2.2 this could indicate that it is needed to cut the light rays at the 'correct' intended position.

It could also indicate that they would not design a 'door' without the waterhouse 'blade'....

[Björn Carlén]

Another simle test would of course be shooting the same object once with the 2,2 blade, and once with just an empty waterhouse. I've just been too lazy for that up until now.