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Canon 400 f4 v 500f4 (1 Viewer)

I think the formula in comparing image size of 2 lenses involves squaring each lens focal length then dividing. For example in comparing image size of a 500 & 600mm lens > (600x600)/(500x500)=360000/250000=1.44. So a 600mm lens will produce an image 1.44 times larger than a 500mm lens at the same distance.
I think this is correct & is essentially what you are saying (with respect to a 500 & a 600 lens) but perhaps someone can confirm or refute this. ;)
NOTE if comparing a 200mm & a 300mm lens > 9/4= 2.25.
 
Robert Davis said:
These lenses are heavy and large. If you can use a tripod the 500 f4 cannot be beaten. FOR A MORE VERSATILE CHOICE THAT CAN BE USED HAND-HELD, I VOTE FOR THE 100-400 AF IS ZOOM.
ROBERT DAVIS.
I switched from the 100-400 to the 300 f4 + 1.4x teleconverter, agreed that its not as flexible but, IMHO, it handles so much better. And, yes I did have both for a couple of weeks before deciding to sell the 100-400.
 
Steve G said:
I think the formula in comparing image size of 2 lenses involves squaring each lens focal length then dividing. For example in comparing image size of a 500 & 600mm lens > (600x600)/(500x500)=360000/250000=1.44. So a 600mm lens will produce an image 1.44 times larger than a 500mm lens at the same distance.
I think this is correct & is essentially what you are saying (with respect to a 500 & a 600 lens) but perhaps someone can confirm or refute this. ;)
NOTE if comparing a 200mm & a 300mm lens > 9/4= 2.25.

Presumably, this is a 1.44x increase in area - am I right in thinking that something that measures, say, 10mm across on the film/sensor with the 500mm lens will be 12mm with the 600mm, not 14.4mm?
 
Adey Baker said:
Presumably, this is a 1.44x increase in area - am I right in thinking that something that measures, say, 10mm across on the film/sensor with the 500mm lens will be 12mm with the 600mm, not 14.4mm?

Yes, as I understand it...and the arithmetic works too!
10*10 = 100, 12*12 = 144, so 44% increase in area.
 
Adey Baker said:
Presumably, this is a 1.44x increase in area - am I right in thinking that something that measures, say, 10mm across on the film/sensor with the 500mm lens will be 12mm with the 600mm, not 14.4mm?
Yes it refers to area rather than a one-dimensional measurement so as you suggest a 1mm line @ 50mm focal length will be 10mm with a 500mm lens & 12mm with a 600mm but the area of a 1mmx1mm square @50mm focal length will be 10x10 @ 500 & 12x12 @ 600 > difference of 1.44.
 
400mm DO review

Hi,

I'v just included the 400mm DO to the reviews and have added my thoughts on it. Now wee need some more opinions on it...and on the 500 for that matter.

Russ

Russ Jones said:
Hi,

I just picked up a 400 DO and have had the chance to test it out a bit. This lens is exactly what I needed. The image quality is indistinguishable from the 500mm or any other L lens to me and the size is a dream. With my 20D I get a 640mm F4 and with a 1.4x TC I get 896mm F5.6 in an easily hand-holdable package, that's pretty sweet. I'll write up my thoughts of this lens in the reviews section after I'v had it for a while but my first impression is WOW.

Cheers,

Russ
 
Russ Jones said:
Hi,

I'v just included the 400mm DO to the reviews and have added my thoughts on it. Now wee need some more opinions on it...and on the 500 for that matter.

Russ
Thanks Russ, greatly appreciated... those reviews get a huge amount of views.

cheers,
Andy
 
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