Aspherical lenses availability

[simdil]

Hello, I am a newbie in the matter of large format photography and I would like to replace my 150mm lens with an aspherical one, since I am experiencing distorion to my images.
I did my research and as far as I could find out, the only aspherical lenses with copal shutter were made by Schneider Kreuznach (series Super Symmar XL).
Those series are now discontinued and I am having trouble to find good alternatives and good offers on Ebay (I live in EU).
Can you suggest me any alternative to the Super Symmar XL for my 4x5" camera? Did I get it wrong that Schneider Kreuznach Super Symmar XL are the only aspherical lenses available?
Thank you and have a nice time.

[mdarnton]

First, what kind of distortion are you experiencing? That doesn't sound right. Any good lens should have virtually none.

Second, if you really do have a oerceivable distortion problem, in a general way apo process lenses won't have any, some more than others, and they'll be a lot cheaper. There's even a special apo-Artar for mapmaking with virtually no distortion at all.

[Oslolens]

I suspect you are experiencing distorsion only on three-dimensional subjects? If so, change to a longer lens and move backwards to avoid it.

Sent fra min SM-G975F via Tapatalk

[simdil]

Thank you all for the hints. I am not able to say which kind of distortion. I assume it is spherical aberration, since it happens in particular in the the peripheral part of the frame. I even wonder whether I am doing something wrong with the camera controls... As I said, I am a newbie.
I have attached one shot where the subject (tower) appers wonky and the shpere is stretched (low res compressed jpg). Lens: Schneider Kreuznach Symmar-S 150mm

[Bob Salomon]

Lots of lenses use at least one aspherical element. Check the Apo Sironar W and S series from Rodenstock.

[Dan Fromm]

OP, you have slight barrel distortion. This is an off-axis aberration that can be reduced by stopping down.

What lens(es) did you use to take those pictures? What aperture(s) did you shoot at?

[Oslolens]

I suspect you are experiencing distorsion only on three-dimensional subjects? If so, change to a longer lens and move backwards to avoid it.

Sent fra min SM-G975F via Tapatalk

Yes, I was right Alternative way to avoid this is to move camera to have the three-dimensional subject closer to center. This will happen with any lens and at any aperture as long as you put it out there. It will look even worse when the subject is a face of a person

Sent fra min SM-G975F via Tapatalk

[simdil]

Thank you, I will search. I´ve never considered Rodenstock, so far.

[simdil]

OP, you have slight barrel distortion. This is an off-axis aberration that can be reduced by stopping down.

What lens(es) did you use to take those pictures? What aperture(s) did you shoot at?

I used a Schneider Kreuznach Symmar-S 150mm, I shot at f/16 1/15 sec., due to windy weather condition.
Thanks for the tip, I´ll try to stop down.

[simdil]

Yes, I was right Alternative way to avoid this is to move camera to have the three-dimensional subject closer to center. This will happen with any lens and at any aperture as long as you put it out there. It will look even worse when the subject is a face of a person

Sent fra min SM-G975F via Tapatalk

I see. So this will happen regardless of using a aspherical lens specifically designed to avoid such distortions?
I had no idea, thank you.