In article <46lfb9$g46@cn1.hw.ac.uk>, phydab1@clust.hw.ac.uk says...
>Okay, what makes a tilt/shift lens so expensive ?
>If I find a cheap second hand standard or wide angle lens and modify >the mount to allow the requisite movements will the image quality be >acceptable?
---No. Standard and wide-angle lenses for 35mm have no excess coverage,
---so tilting or shifting them would result in serious vignette.
>Does a lens of this type have to have to be designed to have a very >large field as it is not always the centre that's being used ?
---Yes, generally PC's for 35mm are designed to illuminate about a 66mm
---image circle, and to be reasonably sharp over most of that circle ---when stopped down.
>Surely just adding a tilt to match the Scheimpflug (spelling ?) >condition can't be too difficult. Has anyone tried it ?
---It would be a machinist's nightmare to add to an existing lens
---without affecting infinity focus. Using larger format lenses ---adapted to 35mm would be possible, but none would serve as a ---wide-angle on 35mm except maybe a medium-format fisheye. If a long ---tilt-shift lens is acceptable, enlarging lenses (with a filter to ---compensate the lens color to match your other lenses) or large-format
---lenses can be used on tilt-shift bellows. (I use a Vivitar VHE 150mm
---enlarging lens press-fit into a BR-2 ring [with a strong skylight
---filter to compensate for its green color] on a Nikon PB-4 bellows -
---it works well - even has a 52mm filter thread!)
---Hope this helps.