How to tell a quality lens for new comers

[Bill70]

After doing a lot of research, reading a lot of AP and looking at lens types I have fried the brain & confused myself to no end. Please correct the following

Canon lenses that are marked L & have a red ring indicate that they are quality lenses (This is important to me as I want to go to the canon 40D)

Lenses that have a focal length of less than 25mm are considered a wide lens. (Good for landscapes, portrait photography, groups of people etc.

The lower the f stops on the lens the bigger the aperture which lets in more light making it a faster lens.
Faster lenses allow low light photography & blurring of the background like portrait photography.
Fast lens are also good for longer focal lengths lens as it allows more light through the longer lens.

A prime lens is a lens that cannot zoom, however it is a faster lens letting on more light, has a higher optical quality & is generally cheaper than a zoom lens.

So what I have gathered so far is to choose a lens that has the lowest aperture (f/stop number) in the lens of the focal length series you require.
But how the hell do I know if the optical quality is good.
Is there a number for quality 1 to 10 or glass type?
What are the types? What good & what not?
I see many recommendations on lenses but do not understand why.
Can anyone explain & correct anything wrong that I have written so far.
Cheers

[pgbphotographytas]

You are correct with most of what you said above.

As far as if a lens is "good" that would be a matter of looking online for reviews and posting on here and asking what other members think, I would say except for some very expensive / specialist lenses then somebody on here would have at least some experience with most lenses on the market.

Paul

[jim]

This looks about right to me, except that prime lenses are often much more expensive than zooms (due to the wider aperture and the fact that they tend to be aimed more at pros/serious amateurs.) Though there are more serious and expensive zooms around now than there used to be.

[negatron]

This is where you post on forums liek this, because there is no rule of thumb.

look at the 70-200 f2.8 range of lenses across the brands.

They're all relatively expensive. but what makes the sigma version (lots of generations, inconsistance product quality for some) better than the tamron (slower AF speed) or say the tokina (known to have lost of soft copies floating around)?

each use lots of fancy marketing stuff (APO glass, L markings, SP markings etc)

It depends on what you want to use it for and how much you want to spend (canon 70-200 f2.8 IS for those without buget limitations)

Lenses are selected for producing good pictures->

so I look for

Sharpness
Contrast (important for me as an ex minolta user lol)
AF speed
build quality
Apature speed (Bokeh!)

As for canon L lenses, not all of them are created equal, and some have had MK2's released to improve on MK1 issues.

I guess the short answer is, there is no rule of thumb or scale. Post what you are interseted in here and look at samples pictures...

[Bill70]

Thanks guys for your comments.
I was hoping there would be an easy way to tell, but as all of you have said in one way or another, talk to those who have already used them and get opinions from the forum.
It just makes it difficult to sift through everyone’s preferences when you’re a new comer to photography, but then again everyone else has different styles & preferences.
Thanks again

[JM Tran]

go here for lens reviews and sharpness ratings www.photozone.de

not all L lenses are optically excellent, there are 3rd party lenses which rate better than their equivalent L lens in terms of sharpness and bokeh

L stands for Luxury and u are also paying for the high construction quality, dust/weather sealing on some, and USM and IS and all that jazz

[pgbphotographytas]

Thanks guys for your comments.
I was hoping there would be an easy way to tell, but as all of you have said in one way or another, talk to those who have already used them and get opinions from the forum.
It just makes it difficult to sift through everyone’s preferences when you’re a new comer to photography, but then again everyone else has different styles & preferences.
Thanks again

I can totally relate to what you are saying and yes everybody does have different views but a few things I think most people do agree on.

At the end of the day you are not going to buy a "bad camera or lens" just not what could be the best one for you.

If most people on here say the same thing then I would be fairly sure it is the right way to go.

Paul

[TOM]

Bill, you are right, what you mostly pay for in a lens is speed. All modern lenses will perform well stopped down. The step from F2 to F1.4 in terms of engineering is huge. It is very well to build a lens with a large f stop, but making it sharp from corner to corner is a real challenge. This is why lenses, on a small sensor, can 'box above their weight', because the whole lens area is not being used. The Nikon 70-200 was a reveered lens until it was used with full frame cameras.

Wide angle lenses are great for landscape but so are standard and telephoto lenses. Where the wide angle lenses shine is their greater depth of field and their ability to get close to a subject. They are not intented to cram as much into the scene as possible, sometimes less is more. Traditionally, wideangles aren't used for portraiture, although I love using my 35mm lens for candid 'environment' portraiture.

Boke can make or break a lens as well Bill, and with a fast lens, particulary in standard to telphoto lenses, you will have buckets of it if you like to get close to your subjects. I am really after a super fast 35mm lens and the Voigtlander was on the short list. However, after shooting with it and viewing alot of images from this lens, i find the boke harsh and therefore I will not buy the lens.

[Bill70]

Thanks for the conformation Tom.
I take it Boke or Bokeh as I have seen it spelt before is the name for the out of focus effect given by the lens correct?