conversion

I'm a little confused about the 1.6x conversion.

I would rather buy used equipment than new, and there seems to be more of a selection with 35mm lenses than digital in the used camera market, my question is this:

If I wanted a 70mm-200mm lens for my XT. Could I buy a Canon 35mm auto lens of 35mm-135mm/f3.5-4.5 and have the equivalent of a digital 56mm-216mm lens? Am a way off base here?

tonyhipps wrote in post #2059282
I'm a little confused about the 1.6x conversion.

I would rather buy used equipment than new, and there seems to be more of a selection with 35mm lenses than digital in the used camera market, my question is this:

If I wanted a 70mm-200mm lens for my XT. Could I buy a Canon 35mm auto lens of 35mm-135mm/f3.5-4.5 and have the equivalent of a digital 56mm-216mm lens? Am a way off base here?

sounds right to me but there are better lenses like the 28-105 or 28-135 IS.

ed rader

yeah, you got it. sigma is also releasing a 50-150mm f/2.8 dc, which in 35mm terms is 80-240mm f/2.8 - just informing you should you want to check it out. but you've got to remember that it is an aps-c designed lens.

It will give you the equivalent field of view of a 56mm-216mm lens - It will NOT change its focal length as such.

tonyhipps wrote in post #2059282
I'm a little confused about the 1.6x conversion.

If I wanted a 70mm-200mm lens for my XT. Could I buy a Canon 35mm auto lens of 35mm-135mm/f3.5-4.5 and have the equivalent of a digital 56mm-216mm lens? Am a way off base here?

If you want the magnification of a 70-200mm lens, you have to buy a 70-200mm lens, regardless of the crop or conversion factor. Because the 1.6x sensor is smaller than the 35mm film frame size, an object of a given size at a given distance will fill more of the frame than it would on 35mm film, but it will be the same size.

I think of it like this. You still have the same lens, same focal length. You're just only capturing the middle portion of the imaging circle of the lens, so you have a different field of view.

red hot sheep wrote in post #2060871
I think of it like this. You still have the same lens, same focal length. You're just only capturing the middle portion of the imaging circle of the lens, so you have a different field of view.

nice. good old crop factor debate

You can see it as above.
Or, if you think of 2 cameras of, for ex 10mp, one full frame and one 1.6, at 200mm your 1.6 will indeed capture the middle portion of the image. But that middle portion will have 10mp. So using 1.6x200=320mm on ff will give you the EXACT picture as using 200mm on a 1.6

Tony, when you say , "I wanted a 70mm-200mm lens for my XT" are you speaking in the context of having used a 35mm film camera and liking the subject content captured with a 70-200? If you used a 35mm film camera with 70-200, then you want a lens with the 30-35 to 125-135mm extremes of focal length. red hot sheep is on target with his comment. See my illustration...

Wilt wrote in post #2061098
Tony, when you say , "I wanted a 70mm-200mm lens for my XT" are you speaking in the context of having used a 35mm film camera and liking the subject content captured with a 70-200? If you used a 35mm film camera with 70-200, then you want a lens with the 30-35 to 125-135mm extremes of focal length. red hot sheep is on target with his comment. See my illustration...

Shouldn't this be a sticky? Its really the best visual to answer this question which understandably, arises very frequently?

and what about 1.3x?
I am saving for 1DsmkII and 500mm from now reached 2/3 of total cost, wish to me a good luck.

Tareq wrote in post #2061758
and what about 1.3x?
I am saving for 1DsmkII and 500mm from now reached 2/3 of total cost, wish to me a good luck.

Just imagine my same illustration, with the green area a bit larger! and annotation "Subject area seen with 130mm lens on FF camera, Subject area with 100mm lens on 1Ds"

See this thread for a good explanation of the "crop factor": Crop Factor Explanation

JNunn wrote in post #2061626
Shouldn't this be a sticky? Its really the best visual to answer this question which understandably, arises very frequently?

I was just going to say the same thing...

runninmann wrote in post #2060741
If you want the magnification of a 70-200mm lens, you have to buy a 70-200mm lens, regardless of the crop or conversion factor. Because the 1.6x sensor is smaller than the 35mm film frame size, an object of a given size at a given distance will fill more of the frame than it would on 35mm film, but it will be the same size.

And this simple fact is so not understood by many.

Wilt wrote in post #2061098
Tony, when you say , "I wanted a 70mm-200mm lens for my XT" are you speaking in the context of having used a 35mm film camera and liking the subject content captured with a 70-200? If you used a 35mm film camera with 70-200, then you want a lens with the 30-35 to 125-135mm extremes of focal length. red hot sheep is on target with his comment. See my illustration...

Thanks everyone I understand now.

Wilt, I've been studying wedding photography for a couple of months now and in a year or so I hope to be charging for it. I've read a lot on this forum that a 70mm-200mm is one of the lenses typically used for weddings. That’s why I was asking about the 35mm equivalent.

Ed Rader points out that the 28mm-105mm is a better lens, would this be true for weddings as well?