As I said in my initial post, at 250mm wide open the physical aperture is 45mm. I have no idea what point you want to make here.
Which part of "from the same distance" did you not understand?
...that the physical aperture at 250mm does not tell you what the physical aperture is at any other FL. If you are only talking about 250mm, then you have a point but you did not make that clear. In no way the 55-250 is just 1/3 slower than the 70-200/4.
What part of better resolution don't understand? The better resolution of the L zoom gets you very close to the advantage of the larger FL - the difference is like 7-8% after you factor out the 50mm advantage of the EF-S.
So what? It is a different AOV. Is your 55-250 better that the 24LII because it resolves more detail from the same distance? If you are desperate for FL, then yes, that helps. But if you need the 200mm AOV, your lens does not resolve more detail.
Wish you had kept your samples up so that I can see them. Without seeing them, I bet those were taken in good lighting and were of a still subject. In that case you cannot see a $1,000 difference. If that's what you need a tele for, it makes sense to save the $1,000.
I own both lenses and I'll be darned if I see $1,000 difference in them. IMHO everybody should get the 55-250mm before Canon figures out they are giving away near L's at bargain prices.
Yes, of course!
It was clear in the context of the thread.
Try to read again the thread, maybe it becaomes clear in which sense the 55-250 at 250mm is less than 1/3 stop "slower" than the 70-200/4 at 200mm, both wide open. I said several times that this is not the common usage of slower, therefore quotation marks.
Huh?
OK, so you agree. But, how did you come up with your numbers?
Please try to read the context of a post before responding.
well the other person said he tried it and didn't get sharper resutls from the crop, you'd be surprised how little mm difference in focal length it takes where a much better lens won't be able to bring in more detail than a far crummier longer focal length lens
but his whole point what about when you DO need the extra reach
Yes, I did not get the context. I should not have replied to your post.
If you divide them, you get about 9% advantage. When you crop the 200mm to a 250mm one, you are leaving 200/250 of the image, i.e., 80%. So it makes sense to compute the resulting resolution as 80% of 2500 = 2000, which is about 9% lower. I used the DXO numbers that gave me a slightly different number.
Yes, guilty as charged.
OK this time it's just a warningYes, guilty as charged.
