40 digaron VS 35 sinaron digital... distortion !

[archivue]

how that difference will translate in the real world ?

Anybody have the software to draw grids (distortion patern) from curves ?

Thanks

[archivue]

do you know a better forum to post it in order to have an answer ?

thanks

[archivue]

still looking for users experiences of the 40 digaron...

[rethmeier]

http://toothwalker.org/optics/distortion.html

The 40 has a lot more distortion.

Mainly because of it's retro focus design.

However it will be sharp wide open.

Regards,

Willem.

[CBarrett]

Archie,

I'm giving the 40HR a hard look too, right now.  I also just tested a Nikkor 24 PCe on my D3 which yields a field of view fairly close to the 40 on my P65+.

The Nikkor looked really nice.  Another consideration I was just thinking about... the 40HR is supposed to have an image circle of 90mm.  Given a 40mm x 54mm sensor, this yields only about 6mm of rise, a gain of about 11% in height for the overall composition.  The Nikkor performed well through its full rise of 11mm which yields a height gain of 31% for the composition.  HUGE difference!

I don't have a 40HR on hand to do practical testing, so this is all math at the moment, but MAN!  I need to go reread Rainer's comparisons, but it looks like the dslr lenses are actually going to give you more movement with wide lenses.

Can anyone shed light on my hypotheses?


-CB

[EricWHiss]

Lenses that have simple distortion curves tend to draw a more believable image, while ones like you posted that have components of both barrel and pincushion don't.  They are also much harder to correct in post as well - not that it can't be done - just harder.

And I'd take a distortion free lens over one that's supposed to be super sharp any day of the week.

[Christopher]

Archie,

I'm giving the 40HR a hard look too, right now.  I also just tested a Nikkor 24 PCe on my D3 which yields a field of view fairly close to the 40 on my P65+.

The Nikkor looked really nice.  Another consideration I was just thinking about... the 40HR is supposed to have an image circle of 90mm.  Given a 40mm x 54mm sensor, this yields only about 6mm of rise, a gain of about 11% in height for the overall composition.  The Nikkor performed well through its full rise of 11mm which yields a height gain of 31% for the composition.  HUGE difference!

I don't have a 40HR on hand to do practical testing, so this is all math at the moment, but MAN!  I need to go reread Rainer's comparisons, but it looks like the dslr lenses are actually going to give you more movement with wide lenses.

Can anyone shed light on my hypotheses?


-CB

Rodenstock 40HR-W with around 17mm movement.

Sharpen in PS with 25/0.3/3

http://www.chauser.ch/upload/R40HRW/

[CBarrett]

I'd consider that quite a bit of rise on a 40!  Thanks, C.

Also, are you a little tilted?  Verticals are converging.

-C

[Christopher]

I'd consider that quite a bit of rise on a 40!  Thanks, C.

Also, are you a little tilted?  Verticals are converging.

-C

Yes the 40HR-W allows quite a bit of movements. Certainly more than the 35 Schneider. Know I don't know if I have a great copy of the lens, or if it is quite normal, because as you said, the image circle just states something around 6mm on P65.


Yes, 492m look way to strange without some tilting up.

[brianc1959]

Archie,

I'm giving the 40HR a hard look too, right now.  I also just tested a Nikkor 24 PCe on my D3 which yields a field of view fairly close to the 40 on my P65+.

The Nikkor looked really nice.  Another consideration I was just thinking about... the 40HR is supposed to have an image circle of 90mm.  Given a 40mm x 54mm sensor, this yields only about 6mm of rise, a gain of about 11% in height for the overall composition.  The Nikkor performed well through its full rise of 11mm which yields a height gain of 31% for the composition.  HUGE difference!

I don't have a 40HR on hand to do practical testing, so this is all math at the moment, but MAN!  I need to go reread Rainer's comparisons, but it looks like the dslr lenses are actually going to give you more movement with wide lenses.

Can anyone shed light on my hypotheses?


-CB

The good news is that your math is wrong.  For a 90mm image circle with a 40x54mm sensor the max shift is as follows:

Portrait Orientation:  MaxShift = SQRT(45^2 - 20^2) - 54/2 = 13.3mm
Landscape Orientation:  MaxShift = SQRT(45^2 - 27^2) - 40/2 = 16mm

Note that this shift values are in one direction only starting from a centered position.  The total shift available (e.g. rise plus fall) would be 26.6mm and 32mm, respectively.

[CBarrett]

The good news is that your math is wrong.  For a 90mm image circle with a 40x54mm sensor the max shift is as follows:

Portrait Orientation:  MaxShift = SQRT(45^2 - 20^2) - 54/2 = 13.3mm
Landscape Orientation:  MaxShift = SQRT(45^2 - 27^2) - 40/2 = 16mm

Note that this shift values are in one direction only starting from a centered position.  The total shift available (e.g. rise plus fall) would be 26.6mm and 32mm, respectively.

Right... I tried to skip the math and do it visually in Photoshop, but I think my grid was set at 2mm instead of 1mm.  Once I corrected my grid, it matched your math.  That IS good news... so assuming a vertical shot of a building, you've got about 13mm of rise.

I think I'm ordering the 40HR tomorrow.

: )

Attached is my graphic for the mathematically challenged

[ThierryH]

The good news is that your math is wrong.  For a 90mm image circle with a 40x54mm sensor the max shift is as follows:

Portrait Orientation:  MaxShift = SQRT(45^2 - 20^2) - 54/2 = 13.3mm
Landscape Orientation:  MaxShift = SQRT(45^2 - 27^2) - 40/2 = 16mm

Note that this shift values are in one direction only starting from a centered position.  The total shift available (e.g. rise plus fall) would be 26.6mm and 32mm, respectively.

And that's based on the official Rodenstock tech data. They are famous to be VERY conservative with their "claims" and you can actually go much further than what is indicated, without loss or whatsoever. The Rodenstock Digital or HR Digital allow further to shoot at full open aperture and are sharp already then, till the corners.

Best regards,
Thierry