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P65+, Rodentsock 28 HR, Full image stitched & corner detail

vieri

Well-known member
Hello guys,

as promised in a previous post, I finally got the time to prepare this little sample for you all to see, I think it might be of some interest...

Full shot:


100 % crop of the lower right corner:


The image was taken at ISO 50, f16 with a Rodenstock 28 HR, P65+ on a Bicam with Flexibellows and stitching sliding back adapter, and it's the result of stitching 3 images horizontally. Doing so, gets you way off the image circle of the 28HR; the full image above is basically all the usable area of the 28HR up until the image circle ends. The crop is a sample of the extreme limit of the possible usable area of the circle projected by the 28 HR... plus, you can see some pointed light sources in the crop, and the way the 28HR controls them. The noise you can see in the lowest corner of the crop it's probably due to the lifting of the vignette I had to do in PS - I am quite sure that using the center filter, when it will be available, will take care of this. I am quite happy with this lens sharpness to the extreme corners and with the way CA and aberrations are controlled - I'd say pretty impressive for a lens that wide :D
 

Paratom

Well-known member
How do you like the 28 HR so far?
How much can you shift it with your back?
I am in the process of exchanging my 35HR with a 40HR and wonder if I then might add a 28HR.
However I first will see how I get a long with the 40 and stitching for those subjects where I want wider than 40.
Which other focal length do you use on your tech camera and how good does the 28mm focal length work for you?
 

jotloob

Subscriber Member
The Rodenstock HR 4,5/28mm has an image circle of 70mm .
This lens is outstanding but the image circle is small .
The P65+ back has a sensor of ca. 40x54mm . That gives you a shift amount of 2mm for horizontal/vertical when using the HR 28mm lens .

Therefore you will not be happy with the combo you mention in the title of the thread .

Rodenstock and Schneider are working on WA lenses with a bigger image circle , but it is unknown when they will be on the market and what their focal length will be .

The Photokina will surely show more .
 

Lars

Active member
The Rodenstock HR 4,5/28mm has an image circle of 70mm .
This lens is outstanding but the image circle is small .
The P65+ back has a sensor of ca. 40x54mm . That gives you a shift amount of 2mm for horizontal/vertical when using the HR 28mm lens .

Therefore you will not be happy with the combo you mention in the title of the thread .

Rodenstock and Schneider are working on WA lenses with a bigger image circle , but it is unknown when they will be on the market and what their focal length will be .

The Photokina will surely show more .
Schneider's specified image circles are often much smaller than actual illuminated area - as Vieri's stitched image above shows. Likely there is less field flatness and maybe some vignetting outside the central 70 mm if shooting wide open, but at f/16 that might not be as much of an issue. So perhaps there is a correlation between happiness and f-stop. :)

Vieri, what is the actual image circle corner-to-corner in your stitch above?
 

Paratom

Well-known member
The Rodenstock HR 4,5/28mm has an image circle of 70mm .
This lens is outstanding but the image circle is small .
The P65+ back has a sensor of ca. 40x54mm . That gives you a shift amount of 2mm for horizontal/vertical when using the HR 28mm lens .

Therefore you will not be happy with the combo you mention in the title of the thread .

Rodenstock and Schneider are working on WA lenses with a bigger image circle , but it is unknown when they will be on the market and what their focal length will be .

The Photokina will surely show more .
My sensor is a little smaller, but yes, I allready felt limited with the shift I had available with the 35HR and therefore replace it with the 40mm.

If Rodenstock plans something in the 28mm and smaller focal length range with a larger image circle it would be prefered.
 

vieri

Well-known member
The Rodenstock HR 4,5/28mm has an image circle of 70mm .
This lens is outstanding but the image circle is small .
The P65+ back has a sensor of ca. 40x54mm . That gives you a shift amount of 2mm for horizontal/vertical when using the HR 28mm lens .

Therefore you will not be happy with the combo you mention in the title of the thread .

Rodenstock and Schneider are working on WA lenses with a bigger image circle , but it is unknown when they will be on the market and what their focal length will be .

The Photokina will surely show more .
Indeed the lens is great, despite the smallish image circle - however, on the other hand, until Schneider & Rodenstock will come up with new lenses the 28 HR and the 23 HR are the largest image circle WA lenses available (the Schneider 24 & 28 have only an image circle of 60 mm).

The amount of shift available depends in part on the image ratio you choose; the image I linked above is slightly panoramic, so you get a bit more on width than you would with a 3:2 or 4:3 image ratio before vignette starts kicking in.

Schneider's specified image circles are often much smaller than actual illuminated area - as Vieri's stitched image above shows. Likely there is less field flatness and maybe some vignetting outside the central 70 mm if shooting wide open, but at f/16 that might not be as much of an issue. So perhaps there is a correlation between happiness and f-stop. :)

Vieri, what is the actual image circle corner-to-corner in your stitch above?
Lars, the lens I used above is not a Schneider, is a Rodenstock; but you are of course right, quoted image circle is generally at f11 if I am not mistaking, and would get smaller opening the lens up.

I used the whole width available to me before vignetting in the image above, out of a three image stitch - the original stitch of course showed quite a bit of vignetting.
 

etrump

Well-known member
Pretty impressive IMO, way out of the spec'ed image circle. Seems really sharp for the edge of the glass. I think this would be wider than the 24mm Schneider which has similar quality on the edges of the spec'ed image circle.
 
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