Adding fuel to the 70-200mm lenses fire: Angle of View.

[Hatem Eldoronki]

The Canon 70-200mm f2.8L (both IS and non IS): 30-12 degrees.
The Canon 70-200mm f4.0: angle of view: 34-12 degrees.
The Sigma 70-200mm f2.8 HSM IF: 43-12.3 degrees.

Especially on a 1.6 crop factor sensor, wouldn't this make a big difference in what gets recorded from the lens? Or is it just a minor issue?

Also, magnification:
70-200mmL IS: 1:5.8
70-200mmL : 1: 7.7
70-200mm f4.0: 1:4.8
Sigma 70-200mm: 1:7.8

Seems like major major differences to me!
So does that mean that the Canon IS version is the lens that would get the most elements from a scene at 70mm AND at 200mm in a shot?
(Too many questions!!)

[RockOne]

Where are these figures from ?.
I'm just thinking (and I'm probably wrong here) that they should be the same at the given focal lengths, unless they are not exactly the quoted focal length?

If it is the case then the 2.8 Canons would have the best range of FOV.

[Hatem Eldoronki]

Where are these figures from ?.
I'm just thinking (and I'm probably wrong here) that they should be the same at the given focal lengths, unless they are not exactly the quoted focal length?

If it is the case then the 2.8 Canons would have the best range of FOV.

From B&H corresponding lens' specifications page.

[RockOne]

Mmmm. Interesting. I tried this site and used their calculator. Gives the same results for all three.
And looking at the formulae used seems the only things which affect the AOV are sensor size and focal length. Perhaps there are some physicists around here ? :-). The plot thickens :-)

http://www.sweeting.org/mark/lenses/canon.php

[Mogwyth]

There are plenty of FOV caculaters to be found by searching on Google. The ones I looked at confirmed my suspicions the max fov on a 70-200 lens are the same at infinity regardless.

70 34.35 degrees
200 12.35 degrees

[Hatem Eldoronki]

There are plenty of FOV caculaters to be found by searching on Google. The ones I looked at confirmed my suspicions the max fov on a 70-200 lens are the same at infinity regardless.

70 34.35 degrees
200 12.35 degrees

I am aware of that, and I also think that Canon makes a LOT of typos. On Canon Lens Chart found here (http://www.usa.canon.com/eflenses/pdf/spec.pdf) they state that the 70-200mm f4 has a max magnification of 0.26 at 300mm! So if all the FOV calculators on Google copied that data from Canon, then they're not accurate.

In any case, if they were all the same, then the max magnifaction data would have also been the same for all of them.
Unless I'm very much mistaken.

Rephrasing my original question: Is there a big difference between a FOV of 30 degrees and 34 degrees at 70mm? I'm not that experienced in photography to know the answer, and very curious to find out.

[stuartf287]

The length of the lens (not focal length, but physical length of the lens as a object) might affect FOV. This factor might (I repeat, MIGHT) account for the difference in FOV between the Canon lenses, since the 2.8's are both significantly larger and therefore longer than the F4.

Obviously this can't account for the much larger reported difference between the Canons and the Sigma; I suspect someone made a mistake in posting the data.

[gramps]

I really glad to see this thread.............we haven't had a good crop factor debate in a few days.

[Tom W]

I suspect typos - there's a pretty big difference between 30 degrees and 34 degrees. And the Sigma's 43 degrees is more akin to a 50 mm lens on full-frame. Also, does the B&H ad mention whether these are diagonal, horizontal, or vertical measurements?

FWIW, from Canon's "Lens Works III" book, here's the specs for diagonal angle of view:

All 3 versions of the 70-200 have a 34*-12* angle of view. This is, of course, on a full-frame image.

[PacAce]

My Canon lens brochure lists all 70-200 lenses as having the same FOV so the differences might just be typos.

[Akreager]

My guess is this - The specs you see on web sites, product literature, and etc. are marketing info. In other words estimates. They want the instant recognition of 70-200. In reality it may be 72-205 or 68-210. All companies making all kinds of things do this. I will give you an example from my industry. The industry leader has a product call BA50-100. It is a plastic. Two main way you characterize plastic is by how dense it is and by how it flows when melted. The density of BA50-100 is 0.950 and the flow number is 10. My company and another also wanted a plastic to market to this industry segment. The other introduced a product called K50-10 (see the similarity) and said it is just like the industry leaders product. My company introduced a product called LP5100 (again the similarity) also saying the product was identical. In reality the two competitive products were as follows - den=0.949, flow 11 & den=0.951, flow 11.5 but they were marketed as identical. In addition all three companies do this when comparing two of their own products for the outside world in order to convey whatever message they want to get accross. Unless you are an engineer working for one of the companies or have access to sophisticated test equipment to eveluate all products in a controled envirenment you will never know the exact deal.

My advice - If you are interested in a 70-200 lens, pick the ones you want to evaluate and buy based on performance that really matters like sharpness, speed, contrast, etc.

Also whoever said there are typos in the data sheets is for sure correct. I can no tell you how many times my company has released technical info that has been proofed by 10 diferent people and we look at it and say OH my god! The anwere is usually to let it out and fix it next time. Web based info is making that issue better but....

[Hatem Eldoronki]

I really glad to see this thread.............we haven't had a good crop factor debate in a few days.

Yeah, wasn't that boring?

So, regrardless of comparing between all these lenses, do 4 degrees make a huge difference or not at 70mm? Anybody know?
I know that going from 17mm to 16mm is a big difference on the wide angle side, but is the effect similar on the normal side?
That's all. No debates or anything like that.:oops:

[Hatem Eldoronki]

My advice - If you are interested in a 70-200 lens, pick the ones you want to evaluate and buy based on performance that really matters like sharpness, speed, contrast, etc.

You're right. End of discussion.

[Mogwyth]

So if all the FOV calculators on Google copied that data from Canon, then they're not accurate.


The calculaters do not use manufacturers data they rely on the formula shown on the link below you just enter the focal length and film/sensor size.

www.photo.net/learn/fov (http://www.photo.net/learn/fov)

[Tom W]

Also, magnification:
70-200mmL IS: 1:5.8
70-200mmL : 1: 7.7
70-200mm f4.0: 1:4.8
Sigma 70-200mm: 1:7.8

Seems like major major differences to me!
So does that mean that the Canon IS version is the lens that would get the most elements from a scene at 70mm AND at 200mm in a shot?
(Too many questions!!)

Magnification, in this particular usage, is based on close-focus capability. Often, its listed the other way (the reciprocal of the ratios listed). For example, the f/2.8 IS lens is listed as 1:5.8, which when divided out, equals 0.17X. So, for macro use, this lens will produce an image of 0.17 times the actual size on the sensor. Macro tubes and/or teleconverters will increase this magnification.

BTW, I think that the listed magnification for the non-IS version of the 70-200 is wrong - Canon lists it as 0.16, or 1:6.25, which corresponds to its slightly longer close-focus distance when compared to the IS version. That is, you can't get quite as close (4.6 feet for the IS version, 5.0 feet for the non-IS) so it won't give you quite as large of a macro image since you can't close in as tight.

[Longwatcher]

You know I had never paid attention to the fact that the 70-200 lenses had any difference other then IS and aperture.

But having checked my handy dandy Canon lens chart it shows
all have angle of view of 34 to 12 degree, but the minimum focusing distance is different as is the filter size on f4 lens
70-200/2.8L IS MFD=4.6' filter=77 group/elements = 18-23
70-200/2.8L MFD=4.9' filter=77 group/elements = 15-18
70-200/4L MFD=3.9' filter=67 group/elements = 13-16

I had never noticed that before. Not sure what the number of elements affects, but that extra .3' from the non-IS has probably helped a couple of times.

[Jon]

Angle of view is strictly a factor of the focal length antd the sensor/film format. BUT if you choose a different dimension of the film, you'll get a different angle of view. But looking at the numbers that B&H is reported as giving, I'd suspect a fat-fingered typist who transposed the 3 and 4 on the Sigma and hit the 0 too soon on one of the Canons. The Sigma site and Canon brochure agree (to the limit of display) on the angle of view for these lenses - 34-12 deg., with Sigma adding the decimal points.

Magnification's a different story, and depends on how long the lens' helical (focussing thread/barrel) is. If close focus without extension tubes/close-up lenses is important to you, look at that.

Number of lens elements and groups may have an effect on light transmission of the lens and on lens flare, but that's becoming less and less an issue as multicoating of lens surfaces gets better and more common. You used to lose about 1-2% of light in reflections at every air-lens interface, which made a substantial difference in transmissivity in complex lenses; multi-coating's moved the decimal point over a couple of places.

[Hatem Eldoronki]

Jon, this is a valuable explanation. Thank you very much.