1AP12NV

Hi All!

Newb questions alert

While I'm not quite ready to make any purchases yet, I am starting to consider at least a preliminary list of what lenses I'd like to add to my arsenal in the future. I'd like to do some motorsports photography and also some wildlife so I've got my eye on the Sigma 70-200 f/2.8 for telephoto duty, but I've got two questions that occured to me while reading reviews and looking at lenses in general:

1. I assume that the f-stop rating as it pertains to the lens is the size of the aperture at full-open. Is this correct? If so, what does it mean when a lens has a *range* of f-stop values f/3.5-5.6 for example.

2. I have a Rebel XTi. I've read about it being a crop camera (1.6x i think?) as opposed to full-frame. Are there any lenses that I cannot use on this camera? Are there any lenses that I can *only* use on this camera (I want to make sure that as I invest in lenses I get some that I can use on other Cannon bodies if I decide to later upgrade to a "full-frame" body in the future).

Thanks in advance for your thoughts! I've found this forum to be incredibly helpful!

-Jeff

1AP12NV

I might have just guessed the answer for #1 myself, does the range indicate that the wide-open aperture value changes with the focal length? i.e. f/3.5 at 18.5mm and f/5.6 at 55mm??

If thats the case a confirmation would be appreciated, and still need to figure out #2

GT_2003

1) the first number refers to the largest aperture at the short end, and the second to the widest aperture at the long end.

2) You can use EF and EF-S lenses. As I understand it, EF-S lenses are digital only, for use with APS-C (1.6 crop) sensors only. On full-frame DSLR's and 35mm film cameras, the corners of the image would be noticeably dimmer (vignetting) with EF-S lenses, but the lens won't even mount without modification. The EF-S design means that the lens protrudes farther into the body than regular EF lenses, and on non-APS-C bodies, the mirror would strike the rear of the lens if it were mounted.

1AP12NV

I see.

So if I understand correctly, the EF series would be of equal use to me on my XTi or if I upgraded to a full frame DSLR in the future (I assume that the sigma lens that is labeled simply 'for canon eos' would fall into this category), whereas the EF-S would not work with said full frame DSLR.

Thanks for the information!

Poindexter

Mental Masturbation will get you nowhere

You can use all the Canon-mount EF and EF-S lenses by Tokina, Tamron, Sigma, and Canon of course. You can use more lenses than the more expensive Canon bodies can.

The Sigma 70-200mm f2.8 is a great lens! That was my starter telephoto lens as well. I sold mine to BearNVA a few months ago.

It does just fine for motorsports:

1AP12NV

Haha you guys are no good for my wallet!!!

I def. think the Sigma is next on my list, but I'm not quite ready to shell out another 800+ right now (want to get track seats for the S first ).

But to hold me over and satiate my hunger for camera stuff, I did just snap up a "Nifty Fifty" to play with (obviously not to fill the same role, but with the tiny price tag I figured what the hell). It was also on my list but much easier to stomach the price and I'm eager to play around with a prime lens So hopefully I'll get it in time to play with it at HyperMess this weekend.

I did just get the camera two weeks ago after all

Thanks for the advice and answering my questions though. I feel that at least I know what I'm looking at now when I'm looking at a lens!

1AP12NV

EDIT: n/m just saw the thread


PS> Alex, do I have to do something in particular to get a photo badge?

Poindexter

Rich hands the badges out. I think he does it based on participation in this forum.

RichUK

I'll be updating them in the next few days

1AP12NV