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Ideal aperture for Schneider Digitar 35mm 5.6 XL?

tashley

Subscriber Member
So my Silvestri Bicam arrived with the above lens and, guess what, it seems disappointing. I didn't get time to take a lot of shots but at F11 it clearly has less detail and sharpness across the frame than my Mamy 28 at the same aperture

Am I doing something wrong? I thought the optimal aperture fir these things was F8 thru 11?

Or is it the curse of tashley?

:-(
 

Guy Mancuso

Administrator, Instructor
I know on the Alpa TC it came with spacers for the back if it needed that certain adjustment. I would do some testing on a known distance and see if the back has the correct spacing to the mount on the body. If it is off by a even small amount than it will be obvious
 

Don Libby

Well-known member
While I can’t speak about either the Silvestri or Alpa I can with the Cambo RS. I’ve been using F/8 – F/11 with my 35mm with great success. Agree with Guy re the spacing between lens and back.

don
 
P

Piet Gispen

Guest
I have been using my Schneider Digitar 35mm wih great results on my Cambo Wide DS with the P45+ at f8 through f16 ( simplyhaven't tried other apertures as yet). Results are nothing less than stunning.

Regards,

Piet Gispen
http://www.pietgispen.com
 

PeterA

Well-known member
F11 on my Alpa is the bee's knees. If you arent happy as Guy suggets you probably need to have the back calibrated to the camera. Alpa supplies these spacers - I have never needed to use them on my bodies. You get what you pay for.
 

gogopix

Subscriber
f8-11 worked well for me. I tried f16 and at a 1/250 there is considerable detail in 100% didn't see any diffraction but maybe it was my eyes!

:)

Victor
 

PeterA

Well-known member
That's what I thought when I paid $11,500 for the setup (excluding the back)...

Getting movements using a tiny light capture surface - is a lot trickier than people would have you believe - irrespective of $'s spent. Maybe you have a bad copy of a lens - maybe your cam needs dialling in..I understand your frustration.

the more 'perfect' the capturing medium - the more obvious that flaws in the whole workflow (starting with hardware ) become. I was very disappointed with the Canon 1dsmk11 when I uprgaded from teh 1dsmk1 - then I realised that it required a much closer attention to shooting technique.

@ 30 + megapixels - this stuff is critical though admittedly not particulalrly sexy. -:)
 

tashley

Subscriber Member
I've done some further investigations and worked out that the lens is back-focussing at all distances... but if I set it at F 11 and the distance scale at 5 metres I get good infinity focus. My dealer is talking to Silvestri and we'll see what form of shimming or shaving is required... but at least now I have some frames that sho what the setup will be able to do when properly calibrated...

Peter: you're right. When I read widely that digital MF was now about as good quality wise as optimally scanned 4x5 film I sold my field camera straight away and ploughed vast sums into the Brave New World but people do need to understand what I didn't know at the time: that this area of photography is nowhere near as well-sorted or 'cookie-cutter' as DSLR photography.

On the bright side, once one has fought through the various thorny thickets one will have a clear advantage over the rest of the world... I hope...
:D
 

Bob

Administrator
Staff member
Tim,
Next time I buy a car, I will take you along and have you select one.
I will then buy another.
Where can this man go to get treatment for this? The pyramids obviously did not help.
-bob
 

gogopix

Subscriber
Well, there used to be a system- you slapped one of their lenses on, put on a digital back or even a film back, then it did AF and AE... with P45+ (and recently P65+) seemed pretty sharp across the frame... lots of lenses, no shimming..

It was called Cont... something

:)

Victor
 

Digitalcameraman

Active member
I've done some further investigations and worked out that the lens is back-focussing at all distances... but if I set it at F 11 and the distance scale at 5 metres I get good infinity focus. My dealer is talking to Silvestri and we'll see what form of shimming or shaving is required... but at least now I have some frames that sho what the setup will be able to do when properly calibrated...

Peter: you're right. When I read widely that digital MF was now about as good quality wise as optimally scanned 4x5 film I sold my field camera straight away and ploughed vast sums into the Brave New World but people do need to understand what I didn't know at the time: that this area of photography is nowhere near as well-sorted or 'cookie-cutter' as DSLR photography.

On the bright side, once one has fought through the various thorny thickets one will have a clear advantage over the rest of the world... I hope...
:D

I have had some quality control issues when trying to mount and shoot sharp images on Silvestri View cameras. I had 2 customers buy this setup with the Silvestri sliding back direct from Italy and we found the focus to be off by a large degree. We started our inquiry with Silvestri. They told us they had never tested the sliding backs they were building with digital backs because they did not have any at the factory. At the time we were able to get a local P1 guy in Europe to drop off a camera at the factory. They found a wrong measurement to the film plane. We have seen the same fro other sliding back vendors but they have all solved their focus issues.

I think that they have a neat camera design and I have always like the tilt adapter except it does not work with wider angle lenses.

First lets assume that your film plane is not par focal with the back which means what you focus on is not in focus when captured. One way is to shim the adapter to move the film plane. The other is to go back to the manufacture and get them to make a change in the depth of the adapter which changes the film plane. This is the best choice.

I would first do a focus test with that lens on a piece of newspaper to check to see if it is par focal. You could do this at 5 ft and also at infinity since it sounds like you want to use wide angle lenses. If those test work okay I would also check the back against a second back to see if you get the same results. I think this can confirm that your back is in the correct plane. I have found only a few out of 500 over the last 10 years at P1 that were off.

Good Luck,



Chris Snipes
Phase One Reseller
Phase One Test Studio

www.imageproduction.com
[email protected]
 

gogopix

Subscriber
I have had no problems with two copies of Alpa 'chunks of aluminium" and three phase backs.. two schneider lenses; infinity and even 'scale focus' worked reasonably well.

As Peter said, I guess you get what you pay for...

Victor
 

lance_schad

Workshop Member
I have a client who has the Flexicam and uses it with the Rodenstock 45mm,55mm and 65mm focal lengths and has not complained about the focus at all. He also uses the same lenses on his P3. BTW he is using a p45+ currently.

We all have been aware for sometime that the Schneider 35mm/24mm are a bear to focus on technical camera systems especially ones with a sliding backs. Have you noticed that ALPA, Cambo, etc. have not introduced a sliding back for their wide angle solutions (or any for that matter?). Tolerances are very tight with the wide angle lenses.

I remember when it first came on the market I had a few clients attempt to use it with the most accurate view cameras on the market and wound up switching to either the Cambo and or ALPA wide angle solutions because they worked.

Maybe you want to try a lens that is a little longer in focal length like a 45mm or 47mm and utilize stitching for a wider angle of view.

Lance
 

Jack

Sr. Administrator
Staff member
Tim, you are clearly cursed...

FWIW, focus with a view cam on medium format is HYPER critical, more so than with 4x5 and larger formats, and more so with digital than film as the digital sensor has no depth and film does. The slightest mis-focus with your MF digital back and your image will be soft, period. If you are using a sliding back with Ground Glass (GG) to focus, I suggest at minimum a 10x loupe to confirm focus, and even then if you are off by even a fraction of a mm it will alter your PoF in the image by several meters.

As an example, a 210mm lens at f16 PoF will move from 10 meters to over 100 meters if you move the focusing stage 0.5mm! Obviously, the effect becomes more critical as you go shorter in lens focal, and the same 0.5mm focus error with a 35mm lens would take focus totally out of the image...

Best test is an image with lots of depth so you can see the point you focused on versus where you actually landed, and that assumes you actually landed somewhere in that range, which is NOT necessarily a foregone conclusion.

Best,
 

tashley

Subscriber Member
how are you judging focus when shooting?
1) By loupe on ground glass
2) By tape measure
3) By knowing that a building which is four miles away is for all practical purposes at infinity for a 35mm lens at F11....
:eek:
 
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