How do you tell a good lens (Canon)

[bricat]

Well how do you tell if a lens is good? Yes I know it is white. I am going to purchase a EFS 17-55 2.8 for xmas based on views expressed in threads on here and also other review sites. I am fortunate enough to be on the net to access this information but if you look through the makers catologue and read the speel all the lenses are great. Price? Really it is confusing to me......

[William W]

When comparing like with like: Price is a good indicator, yes.
But the worth of a lens beyond "how good it is" is also in the understanding of the elements of what makes a lens "useful" and what elements will reflect more $ cost.

Three main elements are:
- the maximum aperture
- the focal length
- the zoom range

For example, it is fairly easy to make 35mm 50mm and 85mm lenses and also a lot of these lenses are made, so it is not surprising that a fast 50mm lens (like the EF50F/1.8 MkII) is not very expensive. Nor are the EF35F/2, and the EF85F/1.8 expensive lenses.

But to gain a small amount of lens speed the: EF50F/1.2L; EF50F/1.0L; EF35F/1.4L and two EF85F/1.2L lenses are much more expensive. These L lenses also have other features, other than just being faster lenses; like different optical elements for better contrast, less flare and weather sealing, etc.

Also understand that it is more expensive to make a really fast wide lens or a really fast telephoto lens or a really fast zoom lens than a really fast 50mm lens, so that is one reason why the 24F/1.4LMkII and the 200F/2L IS are a lot more expensive than the EF50F/1.4. And also it is more costly to make a non-varying zoom and this is one reason why the varying maximum aperture zoom, EF-S18 to 55F/3.5~5.6 IS, is less expensive than the EF-S 17 to 55F/2.8 IS – but both lenses might be “good” if both are used at about F/9 at about FL 30mm and if the two images were compared, I expect that not many people would notice a difference in image quality – but I expect that more people would notice a difference in image quality when comparing an image from each lens at each end of the zoom range and both lenses used at their maximum aperture. But also the F/2.8 zoom allows shots to be taken at F/2.8, which the kit zoom does not – and that might be a factor which makes that lens “good” for you – but another person might not require F/2.8 in their zoom lens.

Similarly, it becomes a subjective matter as to whether or not the 50/1.2 or the 50/1.8 is "good" for you: because you can make good photos, with both as can you with mostly all of the range of Canon lenses.

Also a price difference might be reflecting of some specialty of the lens, for example, such as a TS-E lens or a Macro Lens or Image Stabilization.

So once you decide what type of lens you require and the features you want in it, then yes: Price will be a good indicator as to which lens is the better, when comparing like with like and taking onto account the feature differences of the lenses from which you are making your buying choice.


WW

[kiwi]

weigh it, the better the lens the heavier it is

[jjphoto]

There's no simple answer as lenses have many qualities to consider and the ones most important to you might not be as important to the next person. Understanding the various qualities of lenses helps to work out which one is best for you. Some of the qualities to consider are outlined in the link below. Hope it helps.

http://photocornucopia.com/1005.html

JJ

[98kellrs]

My priorities go:

1) Focal length - Subject dependant (i.e I know I want a lens for landscapes so I want between XX and XX mm)
2) Max Aperture - Low-light dependant (good for DOF obvious, but my main use is low-light)
3) Sharpness - A good focal length and a wide aperture are no use if it can't produce sharp images!!

Some people also worry about the amount of distortion, CA, weight etc

[bricat]

I'll first learn how to spell.( spiel)
I considered these lenses mainly around my price point and wants.
EF 24-105 f/4L IS USM $935 grey
EF 70-200 f/4L IS USM $1139 grey
EF 17-40 F4L USM $749 grey
EF 16-35 f2.8L ll USM $1449 grey
EFS 17-55 f2.8 IS USM $933 grey

As you can see I am as money permits going to build up a variety of lenses other than kit. EFS 17-55 f2.8 IS USM will cover the probably most used everyday type lens so I considered the bottom 3 out of these. Value for money was probably a major consideration and when comparing the bottom 2, IS and 17 v 16mm was the stumbling block. However I did not see an EF 16-35 f2.8L with IS which can add maybe 5,6 or $800. to the price and out of my bracket.

So am I being fooled into thinking that IS is an assett on such a short focal length? All EFS lenses have IS. Why? Is this something to do with the 1x6 on 7D and its' equivalent cameras?

Thanks for the information so far and the link which has been very helpful. Every time I come on this site I learn something which is fantastic. cheers Brian

[Ezookiel]

... Some of the qualities to consider are outlined in the link below. Hope it helps.

http://photocornucopia.com/1005.html

JJ

He's updated the site since you posted that link too. He'd left out a chunk of the stuff about vignetting under the "lens aberrations", and when I pointed it out, he had it fixed within about half an hour of my email. If you cut the 1005.html off the end or follow the "home" link at the top of the page, he has heaps of other interesting stuff too.

[LJG]

Brian, one thing you do not mention is what body you have and I do not know. Everybody can give lots of advice, but at the end of the day is the body you have going to be the one you keep? History tell me others who upgrade lenses also eventually get around to wanting a new body. So, if you are going to stay with a crop sensor you can happily surround yourself with quality EF-S lenses like the 17-55. But if you even think you may go FF that is a different story. You can end up with lenses you love, but have to sell, like I did. maybe do some soul searching before you shell out the folding green and be sure you are not going to change your mind in a few months.

[Roosta]

If you buy good glass from the start, you'll have it for the length of time that you have the same mount/crop. But bodies will change and format/sensor size will vary. So, Lloyd makes a valid point, will you stay with the 7D 1.6 crop body? or will you look to go APS-H (1D Body) or FF, them an EF lens would be a better/only choice. It's all relivant to what your going to use to capture the image with.

Look at what some of the regs in your favorite forum are using to capture their images and see if any of that suits your bill. I.E "Kiwi with his 400mm and Nikon kit for Sport" "William with his 24-105mm L F4 Lands/seascapes" Or 'Marry-Anne with her macro work"

The crop factor is something to take into account as the EFOV will alter depending on the CF, but I feel you'd be better served with a lens with an "L" on it.

Just my thoughts.

[bricat]

I have a 7D and I guess I was trying to keep my options open for perhaps a FF down the track but in all honesty you have made me realise that it is a bit of a pipe dream. So as long as I reside myself to that OK. Moving forward(I hate that) I have a lot to learn about the 7D and photography in general so I shall concentrate on that.
I guess that is in part where the lens issue was as the quality of the lens for the money spent was confusing me so all in all it has re-focussed me and I have learnt a bit more. cheers Brian
PS Yes I did follow that link thank you and WW another in depth report

[reaction]

Well how do you tell if a lens is good? Yes I know it is white.

I see you've already been brainwashed educated.

Scientific reviews (lenstip,slrgear) are a good indicator, and there are plenty of 3rd parties that give the EFS 17-55 2.8 a good run. Just don't rely on the reviews that are random people who took a few photos and reckon it's good. Remember like most Canon EFS lenses the 17-55 doesn't come with a hood. One will set you back $75 last I heard, so many people cheap out on that, but it will affect your photos.

Also remember if you ever go full frame your EFS lenses are all good as dust.

[bricat]

I have updated my signiture which shows I have a Sigma 150-500 also. I put that in(yes I know it's white) as I was more interested in finding out about a good quality lens not only L series. One would assume(pun intended for those that know) all "L" series lenses were good quality, and a lot are out of my price range at the moment anyway. So I wanted to know how to judge the quality of a lens. I looked up that site thanks. cheers Brian

[reaction]

As you probably know, L doesn't mean quality. It means weather sealed, EF, and expensive. Many of them are good quality but there are a few that are quite soft. It's probably becoming more of a marketing thing now.

Since you mention it, you should look at Sigma's 17-50 2.8 OS. In my view the tiny IQ increase of the Canon isn't worth the cost or the loss when you sell.

[bricat]

I did look at the sigma but was swayed/wanted canon. If the sigma had been way above the rest then I would have no hesitation in buying sigma. Make no mistake I do want an "L" lens(snob I know) but price dictates how much quality I can get. My next lens will most likely be 70-200 L but that will come in due course. The more differing views from people allows you to consider things that I might not have thought of. Many thanks to those who contributed Brian

[vk2gwk]

I agree with previous posters that it is better to have EF than EF-S lenses as you may upgrade to a full frame camera one day - like I did...
A good source of information and test-reviews of lenses is http://www.photozone.de/all-tests

[bricat]

Had forgotten about that site as I had failed to bookmark it. Thanks and I am fence sitting but still no need to rush. cheers Brian

[phild]

I'd have to say the best way to tell if a lens is a good one is to read as many reviews on any particular lens as you can find, look at any data presented particularly with regard to edge sharpness as that's the one factor that isn't correctable (vignetting and CA are easily corrected). The 16-35L, for example, is acknowledged as being quite soft at the edges, but many users accept some edge softness to have the F2.8 constant aperture, particularly when shooting HD video as zooming with a variable aperture will affect exposure.

Once you decide to buy, see if you can test the lens before buying, not all lenses of the same model perform equally. I don't necessarily agree with buying lenses for the camera you might own, lenses have excellent resale value, so upgrade to Full Frame lenses at a later stage isn't going to cost that much more and as Canon in particular are revising the design of many of their lenses, it may be better to buy EF-S which will be better suited to your crop sensor.

[Papou]

I'd have to say the best way to tell if a lens is a good one is to read as many reviews on any particular lens as you can find, look at any data presented particularly with regard to edge sharpness as that's the one factor that isn't correctable (vignetting and CA are easily corrected). The 16-35L, for example, is acknowledged as being quite soft at the edges, but many users accept some edge softness to have the F2.8 constant aperture, particularly when shooting HD video as zooming with a variable aperture will affect exposure.

Once you decide to buy, see if you can test the lens before buying, not all lenses of the same model perform equally. I don't necessarily agree with buying lenses for the camera you might own, lenses have excellent resale value, so upgrade to Full Frame lenses at a later stage isn't going to cost that much more and as Canon in particular are revising the design of many of their lenses, it may be better to buy EF-S which will be better suited to your crop sensor.

Totally agree, read reviewes and if possible especially if you know anyone with the simmillar lens ask if you can shoot a few test pics with it..Unload them onto your PC , edit and see the results for yourself..And as the addage sez" You get what you pay for" , Buy once and buy good and you wont have to continuousely upgrade lens ..
What happened with me and my 100-400L ..Read reviewes, borrowed and purchased..

[in2fx]

There are many good lenses out there that do not have a red ring around them, you just need to know how to use them to come up with the results that you want.
I do not believe that you always need to have 'IS' either and just keep an eye on your shutter speed and brace the camera if required.
I have 'IS' on a couple of my lenses, but do not always have it turned on unless I feel that it is going to be of help. I used a 100-400mm 'L' for a few months with the 'IS' turned off, and found that I could get away with hand holding it in the 300-400mm range (where the weight transfers much further out) and was able to get lovely crisp shots of lizards eyes amoung many other subjects

[William W]

As you can see I am as money permits going to build up a variety of lenses other than kit. EFS 17-55 f2.8 IS USM will cover the probably most used everyday type lens so I considered the bottom 3 out of these. Value for money was probably a major consideration and when comparing the bottom 2, IS and 17 v 16mm was the stumbling block. However I did not see an EF 16-35 f2.8L with IS which can add maybe 5,6 or $800. to the price and out of my bracket.(*4)

So am I being fooled into thinking that IS is an assett on such a short focal length?(*1) All EFS lenses have IS. Why?(*2) Is this something to do with the 1x6 on 7D and its' equivalent cameras?(*3) . . .

I might have missed it, but I cannot see these points previously specifically addressed.

(*1) – Image Stabilization is indeed an asset if is useful. The 17 to 55 is not necessarily a “short” Focal Length – as at 55mm, it is a short telephoto in respect of the lens being used on an APS-C camera, so in this regard it is similar to having IS on a 70 to 200 zoom when used at the 70mm end on a 5D. Also the 17mm end could be used with IS and IS could be a benefit – an example which springs to mind is for travel indoor architectural shots of the insides of Churches and historic buildings where neither Flash nor Tripods/Monopods are allowed.

(*2) - Not all EF-S lenses have IS – for example the EF-S10 to 22F/3.5~4.5.

(*3) – Yes I concur that you have a point: – if we negate the EF-S10 to 22 – then the EF-S lenses which have IS, all wander into the telephoto range; and the telephoto range is where generally the IS is more useful.
But, noted also the EF-S60F/2.8 does not have IS either.

(*4) – It takes a lot of glass to get an F/2.8 lens at 16mm for an Image Circle to cover “Full Frame” – the EF16 to 35F/2.8L MkII USM is expensive enough as is, and I doubt it would be a useful marketing ploy to make an IS version, considering the lens is essentially used (or the original wasmade to be used) on 1 Series or 5D models (i.e. NOT APS-C sensor) and that for the APS-C model cameras, there is already the EF-S17 to 55F/2.8IS available, which is a fantastic lens, also.

WW