New to the scene, numbers and specs are confusing...

hannakournikova

hannakournikova

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Hi all. i have recently picked up an a200 from Sony, and i really like it.
i am now thinking of buying some more kit.
ideally i would like a tripod, bag and and lens(es)...
i only have the kit lens at the minute, and have been looking at 75-300mm lenses.
what do i need to look for?
F-numbers???...lower the f number...bigger the aperature?? therefore meaning more light needed for fast moving images?? am i on the right path?
i would also like to know about filters??

is there a thread already up somewhere i can educate myself?

thanks all, sorry if this is another newbie post rape :gag:
 
Don't worry about being a newbie - we all were at one time or another!

Apertures control the light passing through the lens to the sensor. A wide aperture (low f number) will let more light through than a narrower aperture (high f number) thus allowing for a faster shutter speed. The width of the aperture also has an affect on the depth of field.
 
F numbers are a fraction, so it's all backwards... F32 is a tiny aperture, F2.8 is a much larger aperture... so the lower the F number, the wider the aperture, which means less time (shutter speed) is required to properly expose the image on the sensor.

There is a good guide to Apertures, Shutter speeds etc on here somewhere, I'll try and dig it out for you :)

EDIT: Here it is: http://www.photonhead.com/simcam/shutteraperture.php

Click round that site too, it's very helpful :)
 
Hello there,

you might want to read a bit of this: http://en.wikipedia.org/wiki/Aperture
That article includes samples, so it's probably better than just summing it here.
But basically, you're right, if you have a lens with a lower f-number, it usually has a bigger aperture, which allows more light to get in than lenses with smaller apertures/bigger minimal f-numbers.
However, the f-number does influence the DOF, so you might often want to stop down to get more depth of field.

Also, if you want to capture fast moving subjects, it might pay off if you got one with fast auto focus. That and some practice with panning.

Sony owners might help you further.
 
i would also say, generally , the lower f number lenses are the more pro quality options.
 
Hi newbie,
don't rush to buy new equipment. You'll find that your money will be better spent if you take a little time to learn the technical stuff and also find out what you want to shoot.
Your Sony can exploit a goldmine of classic Minolta glass in addition to the growing range of Sony and third party products, so you should find it very satisfying. Especially if you take a little time to search out the best of the kit available.

A popular starting point for new Sonoltans would be the classic 50mm f1.7, the glorious 70-210 f4 commonly known as the "Beercan" and 75-300 "Big Beercan". These are really quite cheap as they were produced in great numbers.
Slightly more rare and expensive are the classic APO lenses, the 100-400 being a gem. Then you get into "G" glass territory where the used prices are crazy.
Sony's own range is growing but their production is rumoured to be quite low at the minute, causing high prices. Hopefully Sony are wise enough to realise that their kit needs to be available at street prices that match the competition so this should change.
Popular third party lenses include the Tamron 17-50mm f2.8, Tamron 90mm f2.8 Macro, the Tamron 18-250mm is well liked as a walkaround lens. There is a question mark over some Sigma lenses at the moment as some users have reported that the powerfull focus motors in the latest Sony bodies have minced the plastic gears in certain Sigma lenses!

A valuable resource for Sony/Minolta kit is www.dyxum.com where you can see reviews of all things Sonolta. Have fun ;)
 
Look for a copy of a Book " Understanding Exposure".

A good read.
 
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