18-135IS is not really 135mm at tele end

Discovered about a month and a half ago when shooting with T2i. Focus breathing?

I stood in the same spot and my wife was about 60 feet away from me. I took out T2i and put 135L on it and shot my wife. I then replaced 135L with 18-135Is, zoomed it all the way to 135 and took the same picture. My wife appeared to be zoomed significantly closer with 135L than she was with 18-135 at 135. Some say that focus breathing is ok because the lens is at the stated tele zoom 'at infinity'. However, in this scenario, I was at least 60 feet away, which is pretty much almost infinity for practical photography purposes, right?

Am I right in my conclusion? I wish I had 17-85IS on hand to compare. I have a slight suspicion that 17-85 at 85 would be about the same as 18-135 at 135.

Very possible. Many lenses focal lengths are rounded, it is common.

So that 18-135 IS may be something like 18.5mm-118mm... While the 135mm may be 137mm.

From what I've read, the FL is "approximate" and varies with different types, and even makes of lenses. I wouldn't find it strange at all personally.

Yea I think this is also true with the 24-70. It's like 25.5 to 68 or something. I could be wrong but I remember reading that somewhere

Invertalon wrote in post #14564731
Very possible. Many lenses focal lengths are rounded, it is common.

So that 18-135 IS may be something like 18.5mm-118mm... While the 135mm may be 137mm.

Actually the difference was even more pronounced than 118 vs 137....it felt like 85 vs 135.... In any case I don't have my 135L anymore, but I will check 18-135 vs my 70-200 F/2.8 IS II at 135....

I'm not sure that 60 feet is infinity for the 18-135 set to 135. The real test will be when you compare the field of view of the 135L to the 18-135 when shooting a mountain or ocean horizon. At those distances, the lenses should show a similar (but perhaps not totally identical) composition.

Player9 wrote in post #14564830
I'm not sure that 60 feet is infinity for the 18-135 set to 135. The real test will be when you compare the field of view of the 135L to the 18-135 when shooting a mountain or ocean horizon. At those distances, the lenses should show a similar (but perhaps not totally identical) composition.

You have a point there

absolutic wrote in post #14564727
Discovered about a month and a half ago when shooting with T2i. Focus breathing?

I stood in the same spot and my wife was about 60 feet away from me. I took out T2i and put 135L on it and shot my wife. I then replaced 135L with 18-135Is, zoomed it all the way to 135 and took the same picture. My wife appeared to be zoomed significantly closer with 135L than she was with 18-135 at 135. Some say that focus breathing is ok because the lens is at the stated tele zoom 'at infinity'. However, in this scenario, I was at least 60 feet away, which is pretty much almost infinity for practical photography purposes, right?

Am I right in my conclusion? I wish I had 17-85IS on hand to compare. I have a slight suspicion that 17-85 at 85 would be about the same as 18-135 at 135.

Sixty feet is really not infinity for the purposes of this comparison. Try it again at two hundred and fifty feet or more and I'll bet they'll be much closer to identical. This is often a confusing issue for people. I have several zooms and at less than infinity the size at any specific focal length is significantly different between them. The size difference was still noticeable even at 100 feet. When I focused at a tall building quite a distance away the size differences between 3 of my lenses still noticeable but it was pretty subtle.

absolutic wrote in post #14564727
I wish I had 17-85IS on hand to compare. I have a slight suspicion that 17-85 at 85 would be about the same as 18-135 at 135.

the 17-85mm is probably not an exact 85mm either...most zooms have this issue...

Player9 wrote in post #14564830
I'm not sure that 60 feet is infinity for the 18-135 set to 135. The real test will be when you compare the field of view of the 135L to the 18-135 when shooting a mountain or ocean horizon. At those distances, the lenses should show a similar (but perhaps not totally identical) composition.

Completely agree. Folks often jump to the wrong conclusion when they compare similar focal lengths on different lenses and see huge differences in the viewfinder. It all usually evens out at infinity. However wouldn't it be interesting if reviews could test and compare super zooms to see which has the higher magnification at various focal lengths by distance. For instance if you compared a Tamron 18-200mm to a Canon 18-200mm and focused on a small animal at 200mm and 50 feet away, which would produce the larger image. For some, that might be an important characteristic,

mwsilver wrote in post #14566296
Completely agree. Folks often jump to the wrong conclusion when they compare similar focal lengths on different lenses and see huge differences in the viewfinder. It all usually evens out at infinity. However wouldn't it be interesting if reviews could test and compare super zooms to see which has the higher magnification at various focal lengths by distance. For instance if you compared a Tamron 18-200mm to a Canon 18-200mm and focused on a small animal at 200mm and 50 feet away, which would produce the larger image. For some, that might be an important characteristic,

see u have the Canon 18-270 Tamron with a Piezo. I've heard a lot of criticism of that lens
1) too soft at tele end for anything at all
2) the new Stabilizer is not effective, and makes things soft
3) the af in low light (especially in tele end) is slow to non-existent

How true are these? I used to own its predecessor years ago with 40D and it was unacceptably soft in my opinion. I would not mind having all-in-one for vacation/non-important shooting on 7D. I have 18-135 but assuming, based on our present discussion, 270 on Tamron looks closer at infinity, I might be interested.

absolutic wrote in post #14566381
see u have the Canon 18-270 Tamron with a Piezo. I've heard a lot of criticism of that lens
1) too soft at tele end for anything at all
2) the new Stabilizer is not effective, and makes things soft
3) the af in low light (especially in tele end) is slow to non-existent

How true are these? I used to own its predecessor years ago with 40D and it was unacceptably soft in my opinion. I would not mind having all-in-one for vacation/non-important shooting on 7D. I have 18-135. but assuming, based on our present discussion, 270 on Tamron looks closer at infinity, I might be interested.

Too soft for any thing at all? Don't know about that. It can be a bit soft in the corners depending on focal length and aperture. But its a vacation lens. At 270 it's a bit softer in the corners then I would prefer but still quite decent. The VC is very effective although quite loud compared to Canon IS. It must be turned off on a tripod or the images will be soft.The AF at the tele end is dealing with a maximum f6.3 aperture. Nit really a low light lens zoomed in. In dark situations it can hunt alot. The AF in general is not fast and there is no FTMF. But as a walk around vacation lens for outdoor use or with a flash its really useful.

You're comparing an EF 135L with an EF-S 18-135.

The EF 135L f2.0 is a full-frame lens. The T2i is a crop body. Only the center portion of the image projected by the lens is 'received' by the smaller sensor. As a result, the angle-of-view of the 135L is considerably more "narrow" than what the lens can produce. Think of it like putting horse side-blinders on the lens.

The EF-S 18-135 f3.5-5.6 is designed as a to be a true 18-135 (or close enough for government work) lens on a crop body. The ENTIRE image projected by the EF-S lens is 'received' by the crop sensor (actually, a corner-touching rectangle of the sensor touching the outer diameter edges of the round image projected by the lens). As a result, at the 135 end on the 18-135, your T2i will see the 'full width' projected by the lens.

As an aside, putting the 135L f.2 on a full-frame body such as a 5Diii will produce the same view/angle of view as the EF-S 18-135 does on a crop body.

bratkinson wrote in post #14567219
You're comparing an EF 135L with an EF-S 18-135.

The EF 135L f2.0 is a full-frame lens. The T2i is a crop body. Only the center portion of the image projected by the lens is 'received' by the smaller sensor. As a result, the angle-of-view of the 135L is considerably more "narrow" than what the lens can produce. Think of it like putting horse side-blinders on the lens.

The EF-S 18-135 f3.5-5.6 is designed as a to be a true 18-135 (or close enough for government work) lens on a crop body. The ENTIRE image projected by the EF-S lens is 'received' by the crop sensor (actually, a corner-touching rectangle of the sensor touching the outer diameter edges of the round image projected by the lens). As a result, at the 135 end on the 18-135, your T2i will see the 'full width' projected by the lens.

As an aside, putting the 135L f.2 on a full-frame body such as a 5Diii will produce the same view/angle of view as the EF-S 18-135 does on a crop body.

Sorry. This is complete nonsense. A 135mm lens of any description, designed for any format should produce an identical field of view on a specific sensor. Any variance is down to lens design and nothing to do with format.

I just did a comparison between a shot taken a few weeks ago with my daughter's 18-135mm EF-S and my own 70-200mm L and with them both at 135mm, the 18-135mm is very slightly wider, but only around 5mm at most. Both shots were taken focussed at infinity.

bratkinson wrote in post #14567219
You're comparing an EF 135L with an EF-S 18-135.

The EF 135L f2.0 is a full-frame lens. The T2i is a crop body. Only the center portion of the image projected by the lens is 'received' by the smaller sensor. As a result, the angle-of-view of the 135L is considerably more "narrow" than what the lens can produce. Think of it like putting horse side-blinders on the lens.

The EF-S 18-135 f3.5-5.6 is designed as a to be a true 18-135 (or close enough for government work) lens on a crop body. The ENTIRE image projected by the EF-S lens is 'received' by the crop sensor (actually, a corner-touching rectangle of the sensor touching the outer diameter edges of the round image projected by the lens). As a result, at the 135 end on the 18-135, your T2i will see the 'full width' projected by the lens.

As an aside, putting the 135L f.2 on a full-frame body such as a 5Diii will produce the same view/angle of view as the EF-S 18-135 does on a crop body.

You'd better do some reading up on crop factor and lenses before you inadvertently misinform someone else looking for information! What you stated is easily taken for the truth, I was confused about it myself when I first started using a crop sensor, but it couldn't be more wrong.