Improvising: Long Focal Length Lens

[Simon Rodan]

I hope to do a portrait on 4x5 early next week and the longest lens I have is 18 0mm. I would ideally like to use a 300mm but I can't afford to buy one and woul d prefer not to have to hire one unless I have to.

I discovered after a little experimenting that removing the front cell of my 180 Symmar-S (i.e. using only the rear cell) extends the focal length of the lens c onsiderably (perhaps to around 300 though I have not measured it).

Does anyon e have any thoughts on the viability of this 'improvisation'?

[andrea milano]

unless you need to fillyour format (slides for viewing .....or something like that), it is a lot better to crop your image and let the lens alone (Armin is right it is the front element you should remove.....)the lens performs as a longer lens allright but with a tremendous loss of quality, enlarging is a better option. Most portraits on large formats are done with shorter lenses than the small format, for a number of reasons....