Tech Cameras & Tilts/Swings @ Sensor Plane

[jvora]

Hello All :

Why are the functions of Tilts/Swings at the SENSOR PLANE in Digital Tech Cameras relegated to annals of Analog 4x5/8x10 history ?

I ask this question as when I used to shoot Architecture using a 4x5 camera, I did often used the Tilt adjustments at the FILM PLANE to correct for the Keystone Effect when the Camera had to be tilted up to achieve the correct composition and when Rise/Fall movements were insufficient - By adjusting the Rear/Film Standard to a perfect vertical, the Keystone Effect of converging parallel sides of a building, for example, were the optically corrected.

As an example, attached is an image of a building shot from Street Level - To achieve this composition, I had to tilt the entire camera up which then introduced the Keystone Effect - To mitigate this, all I did on the 4x5 View Camera was to Tilt the Rear/Film Plane to a vertical and the sides of the Building were parallel as they should be. It is this ability I refer to.

Are there any specific reasons why this "feature" is not incorporated in Digital Tech Cameras, like say the Alpa MAX ?

Do Photographers not miss this ability as I have not read any posts lamenting the omission of this "feature" ?

If the Digital Tech Cameras have to be tilted up to achieve the desired composition, is correcting the Keystone Effect then accomplished via PS - Is this what most of you all do ?

I am most interested to learn the reasons for the omission of this control - Are there certain limitations that a Digital Sensor brings forth that may not permit this adjustment, while permitting this option at the LENS PLANE ?



I await your kind replies.



Wishes,

Jai

 

[stephengilbert]

Couldn't this be achieved on the Max by placing the tilt/shift adapter on the rear of the camera?

 

[GrahamWelland]

For those lenses that need at least 34mm of spacing on an Alpa you could use two 17mm 0-6 degree t/s adapters - one in front and one behind to keep the lens & back parallel to each other with the body tilted for the extra rise.

 

[jvora]

Hello Graham & Stephen :

Thanks for the replies - Glad this is indeed possible -

Wondering why then this aspect is not highlighted in Alps's literature !

Any other Brands that offer this "feature" ?

Has anyone out there accomplished this with an Alpa or for that matter any other Brand ? How were the results ?


Thanks,

Jai

 

[jlm]

for this kind of shot, i use the tripod as the way to "tilt" the back, basically bringing it to plumb and level front back, side-side, then shift the lens (in that vertical plane) to get my composition. If i use any tilt of the lens, it is to adjust the focal plane.

i would argue that tilting the entire camera upwards requires you then use movements to get to the same state as above in any case

 

[Frederic]

Given the pancake design of tech cams, I'm not sure a limited swing/tilt would be enough to achieve an indirect shift/rise as done with monorails ?

 

[jvora]

Hello Jim :

I am very interested to learn your approach, but will request you to elaborate more, unsure if I got the technique you mentioned.

--

Frederic :

I see that you say with ref to the pancake design of tech cameras, but some control at the Sensor Plane better than none ?



Thanks,

Jai

 

[GrahamWelland]

I would agree with Frederic that although you can do the body tilt you are only going to see a few extra mm in rise/fall this way. Better to keep it plumb and use regular front rise which can be pretty large depending upon the body. Of course, if you need that extra few mm ....

 

[kapil Syal]

As a general rule (and we all know the pitfalls of generalising) rear standard(film/sensor plane) tilt/swing movements will likely exacerbate the colour cast problems of using digital backs - specially with wide angles. Hence most "technical cameras" tend to emphasise the use of front standard (lens plane) tilt/swings, which only stress the image circle of the lens in use.
AFAIK - the Alpa is the only pancake tech cam that allows mounting the tilt adapter on the rear of the camera - as an option.
Frankly, digital tech cameras are not really comfortable with extreme movements .. but still they are remarkably flexible


..

 

[dougpeterson]

If you get out your paper and pencil and start sketching it out a CameraTilt+SensorTilt is the same exact geometry (concerning the relationship between subject, sensor and lens) as a vertical rise.

On most digital tech camera and lens combinations the amount of total image rise (whether by [CameraTilt+SensorTilt] or by [rise/fall] is limited by the lens image circle, not by the mechanics of the body.

It's also much easier to accurately align the sensor to a building facade when all you have to do is use the built-in-bubble-levels to make sure you're body is level, and then use a single dedicated knob for rise/fall. Using the older tilt-the-body-tilt-the-sensor combo with the resolution/tolerances of high res digital backs will often cause inadvertent sheimflug effects.

In addition, if you hit the limit of rise on any given pancake body you can always tilt the camera up a few degrees and use Capture One (or other similar raw processing software) to correctly keystone the subject. This is undesirable when used to excess but is often an excellent companion to pure-rise when dealing with extreme situations.

 

[GrahamWelland]

Hey, I was basking in the fact that we'd found something that an Alpa could do that a cambo or arca couldn't :ROTFL:

I agree with Doug on the practical approach of rise and then tilt / keystone fix in capture one. Shoot a bit wider to be safe too.

 

[jvora]

Hello Doug, Kapil and all :

Very convincing replies -

I figured something similar to what Kapil mentions but wanted clarifications -

Doug, your approach and reasoning is fully appreciated, specially noting the tolerances of DB when compared to film based systems !

Thank you all for the replies -

I shall sleep better knowing that "control" has not been relegated ; )


Thanks all,

Jai