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Technical Camera Images

dchew

Well-known member
Got a PM asking what I mean by "back fall." I tried to respond directly, but the sender's message box is full, so I thought best to respond here in case any one else wondered.

It may not be the correct use of the term, but I use it when the digital back is shifted down, as in the historic term rise/fall. I think it was standard on a view camera to do "lens rise" to get the top of a building into the frame, but because of the way I normally use the Alpa STC, I have the shift/rise/fall mechanism oriented where the digital back is. So, doing "back fall" is a similar effect to "lens rise" without the change in perspective that results from moving the lens.

When I use that term, there is no reference to tilt or reverse tilt, just the fact that I lowered the digital back down in the image circle. In my recent post of the cabin, it was to remove too much foreground without tilting the camera up.

Dave
 
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PSon

Active member
To all members with questions,
I like to contribute to Dave's detailed explanation. Sometimes front and back rise and fall could be confusing since they work in the opposite. So the way to think conceptually is to use the analogy of the window. Think of the window as a lens which is constant and not moveable and you are the digital back standing behind it. In the case of back fall, you kneel down to look up and be able to see tall objects outside the window. If you use a ladder and climb up to the top of the window, you can look down to view object below from outside the window. The situations of back fall and back rise apply to camera that only have rear shift mechanism and not front. These cameras are like the Cambo WRS series and the Alpa STC which is Dave's camera. The reason that these cameras are very popular is because you can use them easily to stitch images. These cameras allow very wide range of shifting distance since you can shift from one side to the opposite side of the image circle. Thus back shifting camera allows you to use the full image circle for stitching. Basically you can use the diameter of the circle.

In the case of lens rise and fall, the opposite is true. Here you are immobilized and the window can be shifted up to see tall objects or shifted down to see low object. These cameras are like the Cambo Wide DS and the Alpa SWA where only the front lens can be shifted and the digital back is stationary. These cameras are not as useful for stitching but used primarily as perspective control only. These camera will allow you to shift from the center of the lens to the top of the image circle which is only half way of the image circle. Simply you can only use the radius of the circle. The only way to use the diameter of the lens's image circle in these cameras is to mount the lens at the bottom of the image circle and align it to the digital back.
 

Audii-Dudii

Active member
In the case of lens rise and fall, the opposite is true. Here you are immobilized and the window can be shifted up to see tall objects or shifted down to see low object. These cameras are like the Cambo Wide DS and the Alpa SWA where only the front lens can be shifted and the digital back is stationary. These cameras are not as useful for stitching but used primarily as perspective control only. These camera will allow you to shift from the center of the lens to the top of the image circle which is only half way of the image circle. Simply you can only use the radius of the circle. The only way to use the diameter of the lens's image circle in these cameras is to mount the lens at the bottom of the image circle and align it to the digital back.
In the case of the Cambo WDS, at least, another option is rotate the camera by 90 degrees and then rotate the back mounting frame by 90 degrees in the opposite direction so the back's orientation remains the same. This effectively swaps the rise/fall and shift mechanisms, such that the rise/fall movement is now controlled from the rear of the camera and the shift movement is controlled from the front of the camera.

To facilitate this, Cambo added a second tripod mount to its wood grip, but another option (and the one I implemented with my modified Cambo WDS FrankenKamera, wherein I use various 35 mm and medium-format lenses in connection with a Sony A7R body) is to replace the wood grip with a piece of .25" aluminum plate:



I find this orientation preferable to the OEM orientation because I apply a rise/fall movement to almost every photo I take and not having to recompose the photo with each minor adjustment saves time. I stitch photos rarely, so it's not a big deal to spend a bit more time setting up the composition when I do and the fact that shifting the lens instead of the sensor creates a parallax error is also not a big deal because the stitching process will manipulate the pixels to smoothly join the individual frames regardless, so any loss of resolution or fidelity to the original scene is going to be masked and should go unnoticed.
 

k-hawinkler

Well-known member
In the case of the Cambo WDS, at least, another option is rotate the camera by 90 degrees and then rotate the back mounting frame by 90 degrees in the opposite direction so the back's orientation remains the same. This effectively swaps the rise/fall and shift mechanisms, such that the rise/fall movement is now controlled from the rear of the camera and the shift movement is controlled from the front of the camera.

To facilitate this, Cambo added a second tripod mount to its wood grip, but another option (and the one I implemented with my modified Cambo WDS FrankenKamera, wherein I use various 35 mm and medium-format lenses in connection with a Sony A7R body) is to replace the wood grip with a piece of .25" aluminum plate:



I find this orientation preferable to the OEM orientation because I apply a rise/fall movement to almost every photo I take and not having to recompose the photo with each minor adjustment saves time. I stitch photos rarely, so it's not a big deal to spend a bit more time setting up the composition when I do and the fact that shifting the lens instead of the sensor creates a parallax error is also not a big deal because the stitching process will manipulate the pixels to smoothly join the individual frames regardless, so any loss of resolution or fidelity to the original scene is going to be masked and should go unnoticed.
Thanks. Impressive setup. :thumbs:
How do you focus?
 

Audii-Dudii

Active member
Thanks. Impressive setup. :thumbs:
How do you focus?
Um, by turning the focus ring on the lens? Seriously ... it's just that simple. :)

FYI, all the lenses I'm using (at the moment, this includes Contax N zooms and Contax 645 primes, although I have a second lens panel available so I can quickly accommodate several other lens mounts) were originally designed for use on Contax 35 mm and medium-format SLRs, so they come with focusing helicals built-in by the manufacturer.

The only tricky part of the process of adapting them for use on this camera is getting the lens mount positioned exactly at the correct distance from the sensor so the lens is focused at infinity when the distance mark on the lens body indicates infinity. This is important because many of these lenses use floating and/or aspherical elements, both of which must be precisely positioned relative to the focus distance and other lens elements in order for the lens to perform optimally.

But truth be told, it's not all that difficult to achieve that spec within a reasonable tolerance, even when working with very rudimentary tools, provided one works slowly and carefully, removing metal a few thousands of an inch at at time and/or adding shims the same way.

And all the pieces work very well together, too! Unfortunately, while this is definitely a technical camera and I do often use it with medium-format lenses, it's not a medium-format camera, so I don't comment about it in this forum very often. <shrugs>
 

Kinya28

Well-known member
Asia Trip May 2019 #8

Wat Phantao, Chiang Mai, Thailand

It was foretunate that one of my three days visit to Chiang Mai was on Buddha Purnima day, (=Buddha's Birthday). Ceremony started ignition of torch one at a time by young monks and started praying once all ignited. It was quite an experience to observe and capture sacred ceremony at night.

This is the last image from my trip to Asia in May 2019, but plan to visit Japan again soon.

Kinya

IQ3100/ WRS1600/ HR32
 

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stngoldberg

Well-known member
These wild roses(rosa rigosa) populate the sandy beach areas in Middletown, Rhode Island each spring for about 5 weeks.
They throw off a wonderful sweet rose odor that hot house delivery roses do not have These roses number in the millions in a 2 mile region, and then disappear into rose hips until the following spring.
Because the wind was blowing in excess of 12 knots; and because I lose 2 stops due to the necessary center filter on my Rodenstock 32mm lens; I was forced to jack up the ISO on the P1 100 meg back to 400 to freeze (shutter at 1/250/sec) the motion of the roses. I usually try to use an ISO of 64; although I'm not sure that the difference is discernible in a large print
Stanley
 

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DrPaul

Member
This is from Jonathan Dickinson State Park,Jupiter,Florida
IQ4-150 Achromatic, f10,1/160",ISO200
Cambo 1600,Rodenstock 90mmjonathan_dickinson_gray.jpg
 

Kinya28

Well-known member
June 2019 Kyushu Japan Trip #1
Nabega-taki or Nabega fall (鍋ヶ滝)#1

This is my first shooting experience with IQ4150. I am happy to report that I enjoyed using IQ4150 with my Cambo-WRS from day one.

This is my first trip to central Kyushu and found it is very photogenic place. It was short 3 days (3 locations) visit and need to find a chance to visit again and explore more.

Kinya

IQ4150/WRS1600/HR40mm/Focus stacked
 

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Kinya28

Well-known member
June 2019 Kyushu Japan Trip #2
Nabega-taki or Nabega fall (鍋ヶ滝)#2

Same waterfall as previous image. Not so big (30m wide x 10m high) but super photogenic from every angle.

Kinya

IQ4150/Cambo-WRS1600/HR40mm
 

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beano_z

Active member
Looks like typhoon season is almost upon us here in Shanghai, China. Took advantage of it last night shooting from a new location in the light drizzle, you can see the rain catching the last bit of orange sunlight poking through from a gap in the distance.

Used a 3mm upshift on the 150mp back, then cropped to 2:1 ratio in post.

Jing'an Sunset | ALPA 12MAX | IQ4 150MP | Rodie HR 23mm | ISO 50 | F/11 | 30s

P0000767 Shanghai Jingan Sunset - 20-Jun-2019.jpg
 
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