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Focal lens

Focal lens

Focal lens

I would like to know what to expect between a focal lens 125mm and a focal lens 250mm? Is there a difference in focal lenghts I should use. I mean for example if I use -3.3 for focal lenght on ss with the 125, do I have to use, let say -4.3 with the 250. Is the power increase?

RE: Focal lens

Power density increases with shorter focal lengths. Shorter focal length lenses also have a shorter working length. Longer focal length lenses have a wider kerf. It's a tradeoff between these items as to which lens you choose.

Dan - Owner

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