Understanding lense lingo.......

[raztaz]

Hello all!


I just signed on to this forum, actually this is the only forum I've joined! Anyway I liked all the sound advice I was reading and would like some of your input and knowledge to helpme out. To start off I recently purchased my Canon 40D camera. I love seeing the world and people through a camera and so this camera has been a great intro intoamerature photography for me. I have two lenses currently, the canon 50mm f/1.4 and the canon 28-135mm f/3.5-5.6. Eventually I will buy the canon 70-200mm f/2.8 to replace the 28-135mm but that is down the road a ways. I desperately need a good(great) indoor low light lense and need help deciding. When I start researching it leads to so much that I just don't know. Which leads me to a couple of my questions.......the " lense lingo".


One of my questions is what is the difference between regular EOS lenses and the L-series lenses?


My second question is when I see a lense that has f/4L as the aperature, what does that mean exactly?I understand f/2.8 or f/1.4but not the4???


I was planning on buying the canon 17-55mm f/2.8 lense. I've read its a great indoor low light lense but then I saw the canon 24-70mm f/2.8 lense. I can't seem to decipher which would be better.I want a quality lense and would spend the extra$200 if needed.How big of a difference will the 17mm vs the 24mm be?

[Fast Glass]

f/4 is one stop slower than af/2.8, or half as much light. f/1.4 isfour timesas bright ortwo stops birghter than f/2.8. Your 50mm f/1.4 is a much better choice for indoor low light than a f/2.8 zoom.


A L series lens is Canon's top quality pro lens for it's class.


John.

[mikehillman89]

I just signed on to this forum, actually this is the only forum I've joined!

Welcome to the forum raztaz! Glad to hear that you enjoy the reviews that Bryan writes. He does an excellent job with them.

One of my questions is what is the difference between regular EOS lenses and the L-series lenses?

A "regular" EOS lens is simply one of Canon's lenses that they make for their digital camera line. An L-series lens is their Pro line lenses, which usually are weather-sealed, have more durable construction, better optics, as well as lens coatings that keep away weird reflections and such. They're basically the best lenses they make. But as you've probably noticed, they do require a fair bit more in cash... But on the other hand all L lenses come with a hood (which on most non-L Lenses would cost you anywhere from 30-90$ extra) and some even come with a case!

My second question is when I see a lense that has f/4L as the aperature, what does that mean exactly?I understand f/2.8 or f/1.4but not the4???

The aperture refers to how much physical light the lens lets into the camera and hit the sensor. as FastGlass said, a lens with a maximum aperture of f/4 lets in half the light of a lens that lets in f/2.8, and a f/1.4 does double what an f/2.8 does. So the lower the number the faster the lens = the easier it is to use it indoors. In your case, your best indoor lens would be your 50mm f/1.4.

I was planning on buying the canon 17-55mm f/2.8 lense. I've read its a great indoor low light lense but then I saw the canon 24-70mm f/2.8 lense. I can't seem to decipher which would be better.I want a quality lense and would spend the extra$200 if needed.How big of a difference will the 17mm vs the 24mm be?
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I really like the 24-70mm, but also like the 17-55mm... It really depends on what you want later and what your personal preferences are. If you look at these samples from Bryans reviews (They're from tilt-shift lenses, but you can still see the difference between 17mm and 24mm)





As you can see there is a quite a difference from 17mm to 24mm... So in the end it's up to you about which you would prefer; Would you want a wider lens that only goes to 55mm, or do you want one that has a bit extra reach but sacrifices on the wide end. Also, one thing to point out is that the 17-55mm is an EF-S lens, meaning it will not work on a Full Frame camera such as the 1D series and the 5D... So if you plan on upgrading anytime soon, think real hard about getting the 17-55mm as it simply will not work with these bodies.


As well the 24-70 is an L lens so it's better built, has weather sealing and is, in my opinion a better "feeling" lens than the 17-55mm. (I still want the 17-55mm though!)





Hope all this helps!


Cheers,


Mike

[btaylor]

Welcome to the forums mate.


John and Mike have covered things pretty well for you there so there's not a lot to add. However I will say that pretty much everyone that goes for the 17-55mm f/2.8 IS is very happy with it. It will be a very nice lens on your 40D.


I own the 40D and the 5D Mk II and started out with the 28-135mm f/3.5-5.6 as you have, when I upgraded to the 24-70mm f/2.8 I was amazed at the improvement in image quality. The 17-55mm will give you as good/ better image quality as the 24-70 on your 40D. It's not as rugged as the 24-70mm but it's probably a lot lighter (24-70mm is a TANK) and 17mm is reasonably wide on a crop body so will be better for landscape shots than the 24-70mm .


You are right though, it hard to pick between the two lenses - both are fantastic.


Hope this helps,


Ben