A bit more information on the upcoming RF 200-800mm f/6.3-9 IS

[koenkooi]

Your calculation is more elaborate than mine. I simply did a ratio calculation from the primes. Either way, there is clearly some breathing, but it really gives me .2 magnification at 11 ft, I think I will be happy.

Is that 0.2x at 200 or 800mm? Rudy Winston rattled off subject sizes in inches for 800mm and a magnification ratio for 800mm.

 

[Dragon]

Is that 0.2x at 200 or 800mm? Rudy Winston rattled off subject sizes in inches for 800mm and a magnification ratio for 800mm.

According to canon.jp it is .25 at 200 and .2 at 800. https://cweb.canon.jp/eos/rf/lineup/rf200-800-f63-9/spec.html

 

[AlanF]

Your calculation is more elaborate than mine. I simply did a ratio calculation from the primes. Either way, there is clearly some breathing, but if it really gives me .2 magnification at 11 ft, I think I will be happy. As soon as Brian over at TDP gets his hands on one, we will have the full detail.

The calculation isn't particularly elaborate. Use the lens makers equation 1/v + 1/u = 1/f, and calculate v and u to put in it from Canon's specs: v+u=3300mm (the mfd), and v/u = 0.2 (the magnification). You can't calculate the focal length of the zoom by relative magnification with primes because primes also focus breathe, which is why you are out by about 50%

 

[Dragon]

The calculation isn't particularly elaborate. Use the lens makers equation 1/v + 1/u = 1/f, and calculate v and u to put in it from Canon's specs: v+u=3300mm (the mfd), and v/u = 0.2 (the magnification). You can't calculate the focal length of the zoom by relative magnification with primes because primes also focus breathe, which is why you are out by about 50%

Good info to have and clearly the most accurate. My two fingered approach is still useful in that it gives me an idea of what to expect relative to my primes. OTOH, as I said before, seeing is believing.

 

[zarathu]

Good info to have and clearly the most accurate. My two fingered approach is still useful in that it gives me an idea of what to expect relative to my primes. OTOH, as I said before, seeing is believing.

Generally I HAVE TO listen to Bryan(who is a friend) first and then Dustin Abbott. Bryan gives the clear technical advice, and Dustin talks about using it in the field compared to other lenses he has reviewed. I don’t pay much attention to others.

 

[Dragon]

Generally I HAVE TO listen to Bryan(who is a friend) first and then Dustin Abbott. Bryan gives the clear technical advice, and Dustin talks about using it in the field compared to other lenses he has reviewed. I don’t pay much attention to others.

Both good advisors.

 

[AlanF]

Good info to have and clearly the most accurate. My two fingered approach is still useful in that it gives me an idea of what to expect relative to my primes. OTOH, as I said before, seeing is believing.

I would advise against giving two fingers to a Brit as you might not get what you expect.

 

[Dragon]

I would advise against giving two fingers to a Brit as you might not get what you expect.

Ah, yes, "two great countries separated by a common language". It does appear that it is important to note which way the palm is facing. Sometimes there is a bit more subtlety to British language than there is to American language.