Copy to Copy variance - MFD different?

Friend of mine wants to buy the 400 5.6 and he is having this issue where there is at least 2-3 inches of MFD difference between what he rented and what he is considering buying (someone local).

My question is, is this normal? Does it indicate something being wrong with either of the lenses?

Thanks.

That sounds like a normal copy variation. More than I would like to see but I am sure it is within tolerances once you add all of them up.

Isn't the MFD of that lens a few meters? Seems like an inch or two of MFD difference on that lens would be small as a percetage.

If he wants to shoot 400mm and close, then the 300/4 IS with a 1.4X TC would get him much closer with a lot more magnification available.

JeffreyG wrote in post #16113908
Isn't the MFD of that lens a few meters? Seems like an inch or two of MFD difference on that lens would be small as a percetage.

Yes, the MFD on that lens is 3.5 meters which is 11 feet 5 and 51/64 inches.

I just spoke to him know, he said he measured it properly this time from the "sensor plane" and it's exactly 11 cm. I did some basic math, and that's about 3.15% difference.

I'm quite surprised how this can happen, does this mean the glass inside each lens is at a different distance? Which lens would you prefer, a lens that has less MFD than the spec or more? Can this impact IQ in any way?

Thanks for the answers.

TheLensGuy wrote in post #16114036
I just spoke to him know, he said he measured it properly this time from the "sensor plane" and it's exactly 11 cm. I did some basic math, and that's about 3.15% difference.

WHAT is "exactly 11cm"?

The minimum focus distance (measures from the film/sensor plane for that lens is stated by Canon as 3.5m or 11.5ft.

SkipD wrote in post #16114051
WHAT is "exactly 11cm"?

The minimum focus distance (measures from the film/sensor plane for that lens is stated by Canon as 11m or 3.5ft.

11 cm is the difference between where each lens can focus. Unfortunately he had to leave now and I don't know the exact focusing distance (i.e. from sensor to the object). So the 11cm is the "Delta" between each lens. It may be that one is say 5+MFD and other is 6-MFD, I don't know.

SkipD wrote in post #16114051
WHAT is "exactly 11cm"?

The minimum focus distance (measures from the film/sensor plane for that lens is stated by Canon as 11m or 3.5ft.

I wish the MFD for that lens was 3.5 ft.

SkipD wrote in post #16114051
WHAT is "exactly 11cm"?

The minimum focus distance (measures from the film/sensor plane for that lens is stated by Canon as 11m or 3.5ft.

I think you have to write "ft" where you wrote "m" and "m" where you wrote "ft"

I dont understand where this ft came into this thread. I was just saying there is 11cm or roughly 4 inches of difference between 2 lenses in terms of MFD.

TheLensGuy wrote in post #16114173
I dont understand where this ft came into this thread. I was just saying there is 11cm or roughly 4 inches of difference between 2 lenses in terms of MFD.

I think your 11cm statement was just misunderstood initially.
I brought ft into the thread when another poster mentioned that the MFD of that lens may be multiple meters. The point being made was that an MFD of about 11 1/2 feet would probably make a few inches difference between copies negligible.

51/64 - wow I am so impressed. As long as you are wishing for a new/better MFD, why not ask for 1.1 feet? Just being silly. Either you like the copy you own or you do not = simple. Find something else to worry about.

ETS wrote in post #16114066
I wish the MFD for that lens was 3.5 ft.

pwm2 wrote in post #16114077
I think you have to write "ft" where you wrote "m" and "m" where you wrote "ft"

I must have been interrupted between reading the values and typing them. I've corrected the post.... it's 3.5 meters or 11.5 ft.

Looks like you're rubbing off on your friends in the way of absurd lens paranoia. If your friend hadn't rented the lens, he'd never know the difference, and would be happy with his purchase, and out taking photos....

gasrocks wrote in post #16114388
51/64 - wow I am so impressed. As long as you are wishing for a new/better MFD, why not ask for 1.1 feet? Just being silly. Either you like the copy you own or you do not = simple. Find something else to worry about.

There's a story behind why I was so precise, but it's not relevant to this thread.