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Divotor
12-10-2010, 9:12pm
Hi All,

Seems to be a common 'crossover' point in lenses. Just what is the difference between the eg. 17-85mm and the 18-85mm? What does that 10mm difference represent?.....seems to add to the price somewhat!
Laymans terms please!

Perhaps post a couple of comparison pics.

My main interest are landscapes etc.
Considering purchasing one such good quality lens instead of the usual two kit lenses. Your comments here will hopefully influence this choice!
Regards

ZedEx
12-10-2010, 9:20pm
um, you mean 'that 1mm difference'? You won't notice, at all. It's really nothing much to worry about. What 18-85mm lens are you referring to? Also, when comparing lenses, look at the apeture (the number that will read f3.5 or f2.8 for example) and whether it is contant or say f3.5-5.6. The lower the number, and whether or not it is 'fixed', will add dramatically to the price of a lens, among a lot of other things...

RaoulIsidro
12-10-2010, 9:25pm
The difference is 1mm, not 10mm as you mentioned.
In terms of image size, for me, not so much difference.
I have an old Canon 17-35mm f2.8L and have used a new 16-35mm f2.8L, and compared their images side by side.
Image size wise, no big difference. Image quality wise, yes. The independent reviews do justice to the new 16-35mm f2.8L Mark II. :)

Divotor
12-10-2010, 9:31pm
Hmmm...hence my learning curve begins.
Just quoting what seem common lens sizes, but now you have added apeture sizes to the equation. Well perhaps I might get some tips in this area also! :)

Divotor
12-10-2010, 10:43pm
So what is the difference (apart from price) between a fixed (ie. 2.6) and the others (ie. 3.5-5.6)? What won't one do that the other will?

Ok...remembering that I'm mostly interested in landscapes and having that little bit of zoom if needed, budget around a grand. So after looking around a bit, lets try this one.....Canon 15-85mm EF-S f/3.5-5.6 IS USM...is anyone going to tell me this is not a fairly good lens?

ZedEx
12-10-2010, 10:57pm
I'd suggest go to wikipedia and search for keywords like Apeture, F Stop, IS, USM etc. The smaller the f NUMBER, (but physically, a larger apeture) will result in:
- more light entering the lens allowing faster shutter speeds while working in low light etc
- less depth of field (think portraits where you isolate the subject from the background)

I suggest boning up on the very basic, core fundamental aspects of photography: Apeture, Shutter Speed, ISO before embarking on expensive lens purchases not knowing what the nomenclature means.
For the record though, i have heard good reports on the 15-85mm lens and it would be good for your average landscape shot and general walkabout lens

maccaroneski
12-10-2010, 11:04pm
The learning plan in the New To Photography section here will take you right through those concepts and more. A great starting point with practical exercises.

Lance B
12-10-2010, 11:07pm
The difference between 17mm and 18mm is 1mm and about 6% more wide angle view for the 17mm lens. If you think that 6% is worth the extra, then get the 17mm rather than the 18mm. To put it into perspective, so to speak, it is the difference between a 200mm lens and a 212mm lens.

PH005
12-10-2010, 11:09pm
Hi Divotor. If it is landscapes that you are mainly focusing ( excuse the pun ) on , then I would steer you more in the area of a sigma 10-20 or something of similar range. Have a look at some of the posts useing this type of lens. Also , take your camera into a store and just try every option . A fixed 2.8 is just that, 2.8 right across the range of the lens, but a 3.5-5.6 will vary its range depending on the light conditions. Remember, the lower the number, the less light needed, therefore better. Also think about a 50mm 2.8 as a good investment. Happy hunting.

PH005
13-10-2010, 10:20am
I meant 50mm 1.8.

achee
13-10-2010, 11:00am
The learning plan in the New To Photography section here will take you right through those concepts and more. A great starting point with practical exercises.

I'd second that, as well as recommending this site:

http://photonotes.org/articles/beginner-faq/lenses.html

It's fairly easy to read and helped me when I was starting out.