Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: jonstewart on April 12, 2008, 09:48:27 am

Title: Schneider 35XL Question
Post by: jonstewart on April 12, 2008, 09:48:27 am

Hi all,
I've always worked under the assumption that the centre filter would be required when shooting with this lens (Silvestri Flexicam/P45), especially when stitching across the lens.

Could some of you good people, with more experience than me, please confirm this, or outline an efficient alternative (in post).

Many Thanks in advance
Jon

Title: Schneider 35XL Question
Post by: bryanyc on April 12, 2008, 01:29:34 pm

Quote

Hi all,
I've always worked under the assumption that the centre filter would be required when shooting with this lens (Silvestri Flexicam/P45), especially when stitching across the lens.

Could some of you good people, with more experience than me, please confirm this, or outline an efficient alternative (in post).

Many Thanks in advance
Jon
[a href=\"index.php?act=findpost&pid=188919\"][{POST_SNAPBACK}][/a]

Jon,

I'm going to reply not from direct experience  with the 35xl but here it goes.
It the lens is stationary and the back is moving then there should not be a problem.
If the back is stationary and the lens is moving then you may have issues because the relative change of density at the same subject area of the image (I doubt the center filter is 100% perfect).  Of course this could be corrected in pshop.
This applies with or without center filters.  The degree of falloff relative to the amount of shifting you do is something you have to judge acceptable or not, correctable in post or not.

Title: Schneider 35XL Question
Post by: jonstewart on April 12, 2008, 06:05:16 pm

Bryan, thanks for the reply. I appreciate it.

I think that when stitching across the full width of the image circle, with the lens fixed and the back moving, the fall off will probably be significant, hence the need for the filter. While it could be fixed in PS, the time factors and tolerances involved may well indicate that using the filter in the first place would probably be a better solution, but like you, I'm thinking theoretically, not from experience.

Thanks again for  helping confirm my views
Jon

Title: Schneider 35XL Question
Post by: Rick_Allen on April 12, 2008, 08:42:55 pm

I use the 35XL on a WDS with Leaf back. As long as I shoot a plexi exposure at both ends of the stitch (moving the back not the lens) I can use the custom gain app to correct the full off. hope this helps.

Title: Schneider 35XL Question
Post by: Steve_Townsend on April 13, 2008, 12:53:46 am

Hi

I use the WDS with a P45+ and use the CF about 10percent of the time.  The image circle with this lens allows significant shift so when stitching the CF is really necessary.  I have done so without but I was not happy with the results so purchased the CF.  Otherwise I like the falloff without the CF with vertical shift for architecture which is generally what I use the set up for.

Steve

Title: Schneider 35XL Question
Post by: jonstewart on April 13, 2008, 05:18:24 am

Thanks for the replies, guys.

I think the answer is that I should definitely be buying the CF with the rest of the kit, and then use it most of the time. I'll be interested to explore the fall off and the custom gain control when I get it all.

Thanks again for sharing your experience.
Jon

Title: Schneider 35XL Question
Post by: zeitwand on April 13, 2008, 06:17:27 am

Quote

I use the 35XL on a WDS with Leaf back. As long as I shoot a plexi exposure at both ends of the stitch (moving the back not the lens) I can use the custom gain app to correct the full off. hope this helps.
[a href=\"index.php?act=findpost&pid=189093\"][{POST_SNAPBACK}][/a]

Same here! Shooting a white file is a must with this lens. Not only the the fall off is corrected with the Custom Gain Adjuser also the colour cast that accure with this lens.

I think the Rodenstock's are much more gracious in this case.