intro

hello, my name is matt i'm a noob. i just bought a canon XT, kit lens (18-55mm), speedlite 430ex, i have to double check on my other lens as well 100-200mm.

joined POTN to better improve my skills, and hope i can learn a thing or two

off the bat i have a couple of questions, and hopefully some can answer them for me.

1). lens shade.....pros/cons?..​...and what is it's purpose.
2). iso.... what is it and how does it make a difference in a photo.
3). lens speed...how do i tell?
4). lens appature? how to tell and what do the difference #'s mean

i think that is all for now

hope to post photos soon, i have a big interest in vehicle photos, so i will defenitly be in the transportation section soon.

Thanks,
Matt

Welcome to POTN, Matt! You will find a wealth of information and guidance here - so read up and have fun.
To answer your questions:
1. lens shade (or hood) protects front of lens from both physical damage
and stray light (which can produce flare and lower contrast)
2. iso is the sensitivity of the sensor to light - the higher the number,
the lower the amount of light needed to produce a properly exposed image.
However, the higher iso settings introduce more "noise" to the image -
a trade-off that experience and practice will show you what you are comfortable with.
3. lens "speed" refers to the maximum aperture of a lens - the smaller the
number, the "faster" (and more expensive) the lens - i.e; f2.8 is faster than
f5.6 by 2 stops.
4. lens aperture refers to the (adjustable) size of the diaphragm (iris) of
a lens - measured in "stops", it indicates how much light travels through the
lens into the camera. The different numbers indicate how much light -
I'm sure a more in-depth explanation can be found already posted on
POTN.
Most of all, practice, A LOT! Its an ongoing process (35+ years for me) -
there's always more to learn and discover.
Have fun, don't get discouraged, and keep asking question - the nice
people here on POTN can help you with everything buy your love life.

Regards,
Eric


P.S. I always use a lens hood - ALWAYS - has saved a lens from damage several times just recently - buy the cheap e-bay knockoffs to save some money.

Check out this link:
Ben's Newbie Guide to Digital SLR PhotographyPart 1 - Aperture, Shutter Speed, & ISO


As for the lens hood, it's good to have it on especially outdoors. If you are using the popup flash, you probably want to take it off to avoid shadows it may cause (external flash is fine to use though).

And as mentioned, it protects the lens from bumps and damage (I find this ESPECIALLY with larger lenses like my 70-200mm)

thanks definatley appreciate the info!!!!!!!!!!!

got the info on my other lens

EF 80-200 1: 4.5-5.6 ?

thats all i got off of it...any info or should i hit up the lens section?

Made by who? Canon?

Welcome to POTN.

Welcome to the cauldron Matt..

again thanks, hope to get c&c from everyone......

yes the lens is made by canon