Quote:
Originally Posted by rsbfoto
Hi Guys,
I guess you missunderstood me. I did not say it does not focus to infinity. What I wanted to say is that it is very difficult to focus on Infinity with a Macro lens. That is all.
If it is already difficult to focus a 500mm f4 Canon lens on Infinity now imagine focusing with a Macro lens ...
Well it does not cost much to buy a Macro 180mm and try it  but afterwards you have a lot of experience and that is worth it  |
Most people who try to estimate focus to infinity by using the ∞ on
any lens find that it's difficult for astro work to get spot on.
I wouldn't recommend it.
Robert's using a 40D and probably focuses using Live Focus.
I've been using livefocus on the 20Da for years now and never had a problem.
There's also utilities to achieve perfect focus using the various astro software that most people use in the field.
Focusing a macro lens using the above methods wouldn't be any different or harder than focusing any other lens.