Gundlach Radar 12” anastigmat, a soft focus portrait lens?

[Tin Can]

I think it was common

and now I do recall front markings for rotating out for soft

Jim Galli was/is an influential SF guy

I need to dive into my lens bank today

I most likely will be back with pics

[Tin Can]

Pics not necessary

Perhaps we should ask the Wollensak expert

I have 2 iterations of a similar lens, Gundlach 300mm 4.5 Radar is heavier

The second is in better condition, Velostigmat Series 2 300mm 4.5 and much lighter

Some members told us to unscrew front or back to make it slightly SF

[BrianShaw]

@diverisity... So what do the images through the lens look like, either on GG or negs? Are they in focus; are they soft; are they sharp, as Gundlach intended?

[Tin Can]

Both are more sharp if stopped way down

as usual

I need to mount one on a 8X10 Home Portrait lensboard

[BrianShaw]

Both are more sharp if stopped way down

as usual

I need to mount one on a 8X10 Home Portrait lensboard

Thanks, Randy. As one would expect from a Tessar design lens, which both RAdar and Velostigmat (probably) is. The Velostigmat name was used over such a large period of time I'm just not too sure about them.

I was really asking @diversey about his lens. Something looks potentially modified or improperly assembled about it.

BUT... look at this one... it appears very much like yours, @diversity... most don't seem to have as much thread showing as yours and this one... Could this be "normal" manufacturing/assembly variation?

https://www.ebay.com/itm/37432347790...Bk9SR_zvoc-dYQ

[diversey]

Brian: I did see a soft image on GG at F4.5, wide open. It was hard to tell this soft image was due to “soft focus. David

@diverisity... So what do the images through the lens look like, either on GG or negs? Are they in focus; are they soft; are they sharp, as Gundlach intended?

[diversey]

It is hard to believe that the front ring from this high grade lens could not be completely screwed in, even after disassembling and cleaning.

Thanks, Randy. As one would expect from a Tessar design lens, which both RAdar and Velostigmat (probably) is. The Velostigmat name was used over such a large period of time I'm just not too sure about them.

I was really asking @diversey about his lens. Something looks potentially modified or improperly assembled about it.

BUT... look at this one... it appears very much like yours, @diversity... most don't seem to have as much thread showing as yours and this one... Could this be "normal" manufacturing/assembly variation?

https://www.ebay.com/itm/37432347790...Bk9SR_zvoc-dYQ

[Mark Sampson]

The Wollensak Velostigmat is a Tessar design. Some versions allow you to move the front element outward to achieve soft focus (I had a 12" and never tried it). Some people here (Mark Sawyer?) did not think it went far enough, and found even softer focus by modifying the lens barrel to allow more un-threading of the front element. There's a thread here somewhere that explains it.
The Gundlach Radar is a different design with more lens elements, not a Tessar AFAIK. Gundlach and Wollensak were cross-town competitors back in the day. I have not used a Radar lens (a pre-WWII name btw, not connected with today's radar technology), but can't imagine why the front element protrudes, as here. A little testing might give the answer.

[Darren Kruger]

As one would expect from a Tessar design lens, which both RAdar and Velostigmat (probably) is. The Velostigmat name was used over such a large period of time I'm just not too sure about them.

The Velostigmat name was used on a variety of lenses of different types. They were differentiated by the Series label.

Velostigmat Series 1/1a -> Convertible lens closer to a Protar I think.
Velostigmat Series II -> based on the Tessar design.
Velostigmat Series III/IIIa -> Wide angle (not Tessar or Protar based)
Velostigmat Series IV -> lower cost and slower lens which I think is based on the Tessar design.

I hope Whir-Click chimes in as he would be more familiar with the details for each series.

-Darren

[BrianShaw]

The Gundlach Radar is a different design with more lens elements, not a Tessar AFAIK. Gundlach and Wollensak were cross-town competitors back in the day.

4.5 Radar is indeed the Gundlach equivalent of a Tessar design with the extra element to avoid patent infringement: 5 element 3 groups with 2 separated in front of the aperture and 3 cemented at the back.

http://www.eenportfolio.nl/Gundlach_jul1930.pdf

The Radar WA (wide angle) is a completely different lens design.