[Leica] IMG: Foothill Park

[henningw at archiphoto.com (Henning Wulff)]

There are a couple of things at work here. When you have sensor and 
focus plane parallel and the lens axis perpendicular to both, you 
have constant magnification across the image (if your lens has no 
geometric distortion). As soon as you tilt the sensor you vary the 
magnification from top to bottom (side to side if you swing the 
sensor or lens). Because your nodal points will be moving, after you 
shift these magnification will be shifted as well and your two images 
won't overlap properly, so you'll have to scale one of them. 
Refocussing also clearly changes the magnification. A headache all 
around.


At 12:26 PM -0700 4/12/11, Bob Adler wrote:
>Hi Henning,
>
>I think what you're saying is what I suspected. If I shift the back 
>to the top, focus and tilt, then shift the back to the bottom, 
>refocus (tilt probably won't be needed for the far objects), then I 
>will have a different proportion of the image circle recorded on the 
>sensor? Thats because refocusing changes the size of the image 
>circle recorded, yes? And stitching will be difficult?
>
>Thanks for clarifying...
>Bob
>
>Bob Adler
>http://www.rgaphoto.com
>
>On Apr 12, 2011, at 12:05 PM, Henning Wulff <henningw at archiphoto.com> 
>wrote:
>
>>  This is from Not-George, but I've done this kind of stuff at various 
>> times.
>>
>>  One possible solution at this time is to use a scanning back such 
>>as one of the Betterlight's. You have motion problems, and they 
>>have bulk/cord issues, but stitching is avoided and you get 
>>exceptional detail (and huge files). Otherwise, yes, film is still 
>>a good solution. A problem with tilting, shifting and then 
>>stitching the result is that the image size of the parts that you 
>>want to merge in the shift is then usually at different 
>>magnifications.
>>
>>  At present the Canon with TSE lenses makes it easy. But it's no 
>>8x10. The best one shot digital solution right now is a technical 
>>camera and a high-res MF back, but that is also the priciest.
>>
>>  As far as carrying things at altitude: When we went to the 
>>Himalayas, I carried a Mamiya 6 with 3 lenses, a Horizon 150 (MF) 
>>and a couple of Leicas with 5 lenses plus tripod etc and a ton of 
>>film.
>>
>>  We hiked up to 14750ft (4500m). The first day or two were tough, 
>>but then things smoothed out and we went, as our guide used to say 
>>"a little bit up, a little bit down". That meant down 1500-2000m 
>>into the valley and then the same distance up again, over and over. 
>>The sherpas carried the food and tents and stuff, but we carried 
>>all the camera stuff myself plus some clothing. We were advised to 
>>practice by finding a 20-30 storey building at home and practicing 
>>an hour or two each day going up and down the stairs with a load. 
>>It still doesn't really prepare you for altitude, though. The main 
>>thing for the altitude preparation was to clim high during the day 
>>and go down 500m or so to sleep each evening. No one in our group 
>>got altitude sickness. A couple of years later, in the Andes at 
>>comparable altitudes I got altitude sickness and suffered a couple 
>>of days.
>>
>>
>>
>>  At 10:34 AM -0700 4/12/11, Richard Man wrote:
>>>  So George, educate me a bit here please as I don't know the world of
>>>  tilt-shift much except "in theory."
>>>
>>>  So are you saying that the ideal solution, barring that it's not 
>>>digital, is
>>>  a large format camera shooting on film, with a wide angle lens?
>>>
>>>  --
>>>  // richard <http://www.imagecraft.com/>
>>
>>  --
>>
>>       Henning J. Wulff
>>  Wulff Photography & Design
>>  mailto:henningw at archiphoto.com
>>   http://www.archiphoto.com
>>
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       Henning J. Wulff
  Wulff Photography & Design
mailto:henningw at archiphoto.com
   http://www.archiphoto.com