pros/cons of two different lenses at the same focal length?

[Tin Can]

Maybe OP has not bought yet

Some like Convertible lenses, others casket sets

https://www.largeformatphotography.i...l=1#post993721

[C. D. Keth]

Hi all,

I was wondering if there are significant drawbacks in having one lens act like a second one's focal length? For instance, say I have a 240mm lens but like the 360mm look so instead of buying a 360mm lens, I could use more bellows on the 240mm lens to achieve the 360mm look. Does that work as an acceptable substitute or would there be some problems with this method? I take it there would be possible problems, like vignetting on the lens you're trying to extend? Is it simply better just to go for the actual lens focal length as it was originally intended?

Thanks!

I have a feeling you have never had a large format camera in hand to try this out? The bellows don't "zoom" even though it seems like they might. Extending the bellows will focus the lens closer to the camera.

If you want a 240mm "look" and a 360mm "look" you do unfortunately need both separate lenses.