What make a lens cheap or expensive?

[Dolby]

I thought it was *mainly* speed - but browsing SACamera it seems there lens speed is a small factor, as the below are all roughly the same speed but vary greatly

75-300mm F4.0-5.6 R1,799.00
90-300mm F4.5-5.6 R2,099.00
75-300mm F4.0-5.6 R2,799.00
70-300mm F4.0-5.6 R5,499.00
70-300mm F4.5-5.6 R12,499.00

Is image stabilisation on the lens or camera? Is that one of the differences? What is USM? :/

 

[Pooky]

USM stands for Ultrasonic Motor, Canon's technology for ultra fast focusing.

Canon doesn't have in-camera image stabilisation, so they put it in some of their lenses.

The differences in cost are largely because of the quality of the lens glass elements inside...

 

[Dolby]

Thanks Pooky.

So there's no actual 'spec' to go on - as they're all very similar? :/

 

[vash87]

to put it simply, lenses are not all made equally. il give an example from the list you gave..
im assuming the first or third option on the list is the canon EF 75 - 300mm with or without the USM which is as pooky says, the ultrasonic motor for really fast and quiet focusing.
now the canon 75 - 300's were brought out many years ago so the technology and construction are not the same as the newer lenses. canon brought out the 70 - 300 range to take over from the old models and as such, all of these lenses are slightly better, sharper along more of the focal range and also more optimised for modern dslrs. to compare, take the 4th option for 5499.. this is the canon ef 70 - 300 IS USM lens and has both an advanced image stabiliser (making it much more useful in lower light situations without a tripod) as well as the ultrasonic motor which makes focusing a breeze, even with moving subjects. this lens is also generally more well contructed with better lenses inside, so the build and image quality are better.. it also has a more durable metal mounting ring. unfortunately we really have to fork our quite a lot of cash to enjoy these benefits.

 

[Dolby]

Thanks Vash!

Another lens questions : I remember on another thread they mentioned a macro lens is also good for portraits. I'm guessing the reverse applies?

In other words - just about any lens can be a macro? I see switches on some zoom lenses saying 'macro' ... So I'm hoping when I do eventually buy something, I will need only two lenses

 

[bwana]

Thanks Vash!

Another lens questions : I remember on another thread they mentioned a macro lens is also good for portraits. I'm guessing the reverse applies?

In other words - just about any lens can be a macro? I see switches on some zoom lenses saying 'macro' ... So I'm hoping when I do eventually buy something, I will need only two lenses

Good luck with that one.

Many of the zoom lenses with the macro switch (sigma comes to mind) aren't really true macros. You can adapt most lenses to macro photography but then you lose the ability to focus on things further away.

BTW when you ask about lenses it makes it easier if you specify the full name of the lens. Lenses like the Sigma 24-70mm F2.8 EX DG Macro could easily be confused with the 24-70mm F2.8 IF EX DG HSM if you didnt specify the HSM . . . or if you didnt say sigma it could be confused with the Canon EF 24-70mm f/2.8L USM.

 

[BigAl-sa]

There are quite a few factors other than the [numbers] you quoted: brand would come to mind first...

 

[Dolby]

Thanks for the information guys!

I was on my BB so couldnt copy and paste straight from a site. But my query (which was answered) is why they differ hugely in price. With anything else in life, you have specs, features and stats to look at in black and white.

I used to think speed of the lens was THE spec - but I see it comes down to quite a bit (unmeasureable)

 

[swift412]

The last 70-300mm on your list is, if I'm not mistaken. the 70-300mm DO IS USM lens. The DO stands for Diffractive Optics and is an expensive way for them to make long zoom lenses shorter.

The IS means it has optical image stabilising which further adds on cost, which the other 70-300mm also has.

[-]I can't remember off hand but I'm sure that compared to some of the other lenses on your list, the two 70-300mms have[/-] Compared to the lower priced models, more expensive lenses will also usually have better build quality, better focus motors, full time manual focus (you can manually focus even if the lens is set to autofocus) and a non-rotating front element (which means if you have a filter on the lens it won't rotate as you focus or zoom).

But like pooky said, the majority of the cost is going to be coming from the actually elements in the lens. This is why the Canon L lenses are so expensive: most of them have elements made from flourite or more "exotic" materials than normal lenses (in addition to other things like weather proofing, better lens barrels etc.)

(...)
Another lens questions : I remember on another thread they mentioned a macro lens is also good for portraits. I'm guessing the reverse applies?
(...)

Macro lenses can focus much much closer than portrait lenses, which lets you get closer and thus have a bigger picture of your subject. So a lens that is good at macro photography can be good at portrait as well, but a portrait lens won't be able to get as close and magnify the subject as much as a dedicated macro lens.

For macro photography you have a lot of options, you can buy a new (in production) macro lens, you can buy some 20 year old manual focus one and use an adapter, you can use diopter filters (similar to magnifying glasses) on the front of your current lens, you can buy extension tubes (hollow tubes without any glass in them) to put between you current lens and your camera, or lastly you can put a lens reversed (back to front) on the lens on your camera. Lots of options

 

[vash87]

I can't remember off hand but I'm sure that compared to some of the other lenses on your list, the two 70-300mms have better build quality, better focus motors, full time manual focus (you can manually focus even if the lens is set to autofocus) and a non-rotating front element (which means if you have a filter on the lens it won't rotate as you focus or zoom).

that may be true of the DO model but with the 70 - 300 IS USM you do not have the option of full time manual focus, and the front element does extend and rotate while focusing.

 

[swift412]

I stand corrected, thank you

 

[chau]

Good luck with that one.

Many of the zoom lenses with the macro switch (sigma comes to mind) aren't really true macros. You can adapt most lenses to macro photography but then you lose the ability to focus on things further away.

BTW when you ask about lenses it makes it easier if you specify the full name of the lens. Lenses like the Sigma 24-70mm F2.8 EX DG Macro could easily be confused with the 24-70mm F2.8 IF EX DG HSM if you didnt specify the HSM . . . or if you didnt say sigma it could be confused with the Canon EF 24-70mm f/2.8L USM.

Bwana, are any there big differences between the HSM and non-HSM models of the sigma 24-70mm f2.8? Besides the lack of HSM, is the IQ a lot worse than that of the HSM model?

 

[bwana]

Not sure really but I do know that the IQ of the HSM version is comparable to that of the canon model.

 

[chau]

I'm actually considering getting the 24-70mm. I initially wanted to get the 24-105mm but I'm quite liking the f2.8 in the 24-70mm. I think I should just get the HSM or even the Canon model and not skimp on the non-HSM Sigma.

 

[bwana]

I'm actually considering getting the 24-70mm. I initially wanted to get the 24-105mm but I'm quite liking the f2.8 in the 24-70mm. I think I should just get the HSM or even the Canon model and not skimp on the non-HSM Sigma.

For events it's fantastic and it complements a 70-200 perfectly.