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Thread: Stitching back vs geared rail.

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    Stitching back vs geared rail.

    Is there a downside to using a geared rail to move a technical camera left and right vs using a stitching back.

    I have an RM3Di and I am kinda liking not using the sliding back and wondered if I could simply get a geared rail, similar to a macro focusing rail, and use that to create shots that are stitched.

    Thanks.

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    Re: Stitching back vs geared rail.

    Moving the camera sideways on a rail just moves the entire camera a few cm sideways. I am not sure what that would accomplish, unless your subject is very close, and even so, it would move the lens, i.e. change the perspective and give parallax. A stitching back moves the sensor relative to the lens.
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    Re: Stitching back vs geared rail.

    Quote Originally Posted by postman View Post
    Is there a downside to using a geared rail to move a technical camera left and right vs using a stitching back.

    I have an RM3Di and I am kinda liking not using the sliding back and wondered if I could simply get a geared rail, similar to a macro focusing rail, and use that to create shots that are stitched.

    Thanks.
    As above, this would produce perspective/parallax problems in any 3D subject.

    If you move the whole camera, this is a different technique (which I call "move and stitch") it is only suitable for copying flat artwork, and, perhaps photographing relatively 2-dimensioned objects like simple buildings.
    You could use a very long (e.g. 10m) rail for photographing large murals... or you could use a kerb (sidewalk edge) or a laser beam as a guide.

    I am theorizing about an elaboration of this technique for 3-D construction of images apparently taken from an inaccessible "virtual viewpoint".

    You could use a geared rail or a Velmex powered linear actuator to move the rear standard (for shift-and-stitch) and I had contemplated doing this, but it is not worth the hassle if the CAPcam (robotic camera) ships soon.

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    Re: Stitching back vs geared rail.

    Moving the lens relative to the back and moving the camera are not equivalent. A geared rail is more for when the subject is close to the camera (i.e. Macro). Imagine if you were on a bridge with a moderately wide angle lens, the camera perfectly level, horizon centrally framed, raise the camera 20mm and not much happens at all. However by moving the lens relative to the back you can position the horizon easily at 1/3rd or 2/3rds with perhaps several mm of movement.

    - Paul

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    Re: Stitching back vs geared rail.

    Quote Originally Posted by postman View Post
    Is there a downside to using a geared rail to move a technical camera left and right vs using a stitching back.

    I have an RM3Di and I am kinda liking not using the sliding back and wondered if I could simply get a geared rail, similar to a macro focusing rail, and use that to create shots that are stitched.

    Thanks.
    On the RM you have enough left/ right back shift with most lenses to go beyond their image circle anyway, so you don't necessarily need a sliding back...
    Yair Shahar | Product Manager | Phase One | Mamiya Leaf
    e: [email protected] | m: +44(0)77 8992 8199 | yaya's blog

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    Re: Stitching back vs geared rail.

    Thanks for the replies. I knew I was missing something. I have a geared rail that I used for macro shots. I was pondering the need to be carrying a sliding back and well.. thought maybe I could use the geared rail.. but it in hindsight it was a silly thought and I really appreciate the straight forward responses.

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