Rising Front

PaulNWE

PaulNWE

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This was taken one Sunday afternoon to experiment with rising front and how much the lens could be pushed. Image is just going out of focus on the top right hand side.
It was taken 14th March 1993.
Tri-X - 320ISO (Orange filter)
Dev: Rodinal 1:25 9 mins.City 1993.jpg
 
Yes, nicely done. On my screen fall-off in sharpness at the upper right isn't really noticeable. Have a hunch it wouldn't detract from the image in the actual print.

I too am curious as to what lens (and film format.)

David
 
Do you remember what f stop was used ? David has asked my other question already.

Ian
 
PaulNWE said:
Image is just going out of focus on the top right hand side.
Click to expand...
That could depend on whether you used any tilt or swing and where you put your plane of sharp focus. When I first started out in LF, I had to get to grips with movements, Merklingers notes came in very useful, especially the bit that talked about wasting the DoF on the plane of focus by placing the distant sharpness halfway up a building instead of following the ground. Although, in this case, I would have used swing to follow the line of the buildings. This, in turn, meant a larger aperture and less chance of diffraction.

Of course, you may already know all this - in which case, feel free to disregard and let others who don't know find this gem.

Apart from that, nice image.
 
The lens was Schneider Symmar S 5.6 150mm.
No record of the the f stop, but the lens goes down to f45 - so probably f22 - I never use lenses at the extreme to avoid diffraction and soft images.
Film - 5x4 Tri-X - on a Sinar Wolf - it was the only large format I had at the time. Exposed, processed and printed using an adapted version of the zone system I used at the time that seemed to work for me and the equipment I had then. No longer have a darkroom so I rely on digital scanning and printing now.
I really can't remember now, but I imagine I may have had a little swing in place across the plane of the buildings, as Joanna mentioned above. I used 'Large Format Photography' for all my technical information about swings/tilts etc - it came free with the camera!! (see attached) I only took one shot for some reason. Normally I would take two. Sort of belt and braces technique.
Location - Dale Street, Liverpool.
 

Attachments

  • Sinar001.jpg
    Sinar001.jpg
    201.7 KB · Views: 10
Paul, on Photrio a few years ago there was some discussion about the use of f32 and f45. It was noted that some of John Sexton's images were shot at these apertures to gain that bit of extra DOF. I've certainly used f32 quite a number of times with my 150mm Sironar N, and f45 a few times, I've not noticed any softness caused by diffraction.

Ian
 
I had problems with slightly out of focus images when using f45. I bumped into Paul Barkshire one day (he produced two books of photographs of London using a 10x8 camera) and during our conversation I happened to mention the problem I was having at the time. He said it was diffraction and if I avoided the extremes of the lens, the images would be sharp. I tried and it seemed to solve the problem. From that point I have avoided using f45, especially with that lens, and it seems to have kept me out of trouble. I guess it is one of those habits which sticks?!
Paul
 
PaulNWE said:
I had problems with slightly out of focus images when using f45. I bumped into Paul Barkshire one day (he produced two books of photographs of London using a 10x8 camera) and during our conversation I happened to mention the problem I was having at the time. He said it was diffraction and if I avoided the extremes of the lens, the images would be sharp. I tried and it seemed to solve the problem. From that point I have avoided using f45, especially with that lens, and it seems to have kept me out of trouble. I guess it is one of those habits which sticks?!
Paul
Click to expand...

You are almost certainly diffracting at f/45 but it's a tradeoff. For a given image, what is more noticeable: Diffractive effects or soft focus because of lack of DOF at larger apertures? In many cases, moving the plane of focus with camera movements can vitiate the DOF concerns and one can use a larger aperture.

Like you, I avoid not only the smallest aperture, but also the largest in all but the most extreme situations as a matter of good photographic hygiene, but I do allow myself that freedom when- and as called for.
 
I prefer to stick to f22, but f32 if needed. There may be some differences when it comes to lens design, I have a Schneider 150mm f5.6 Xenar and the aperture scale goes to f90, my 150mm f5.6 Sironar N is marked to f64

The discussion mentioning John Sexton was over 20 years ago, on the US Large Format Forum, to quote: "I was rather surprized to read that John Sexton used f32 in 50% of his shots in Listen to the Trees and f45 in 20%." I remember doing a quick check at the time and found that was correct.

I think it's about knowing the limits of our lenses.

Ian
 
My understanding is that diffraction is a function of the physical diameter of the lens so the longer the focal length the smaller your f stop can go before you notice it. I generally don't go below F32 with 5x4 but have a 300mm F9 which can go down to F128, but probably wouldn't go below F64 with this focal length.
 
Lenses don’t go down to very small apertures because it’s optically desirable, but because shutters have a certain range of detects, irrespective of focal length. It would cause dissatisfaction among customers if there were unlabelled “ghost” stops on a lens.
 
Well take 3 lenses of 150mm FL all in the same #0 Copal shutter, the Symmar S is marked to f45, the f5.6 Xenar to f90, both Schneider, then the Sironar N is marked to f64. And there re un-marked Ghost stops on the Symmars and Sironars., both would stop down to f90.

The general assumption is that the smallest marked aperture is softer due to diffraction, so we tend to not use it.

Ian
 
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