TAMRON 28-105mm F4-5.6 IF PAF Fit on K100D ????

Guys , how does this lens rate on a Pentax K100D or similar

Does the focal length when on the K100D equate to 28 - 105mm or does the magnification alter .....might be a stupid question but just found one on the internet for £119.

Anyone using one

The focal length is fixed. What changes is the angle of view because the small area of the Pentax digital sensor (compared to 35mm film) effectively crops the image by a third.

This is a function of the size of the sensor. It has nothing to do with the lens, except for the fact that your 28mm focal length at the wide end will be equivalent to 42mm on a 35mm film camera.

G

Thanks for the response , still a bit stumped , what I'm looking for is something to go on the K100D as an alternative to its 18-55 , more of a
reach between 18 or 28mm and 150/200mm.

Any suggestions , on a limited budget !!!!!!!!!!

On a limited budget, stick with what you have. It's pretty good. If your budget is very limited and you don't mind MF and manual exposure, buy an SMC Pentax-M 1:4 75-150mm.

Less than £20.00 on Ebay, but a very fine lens.

G

I've got the Pentax 28-105 f4-5.6 IF which I believe is fundamentally the same lens. Only real exception is that the Pentax has SMC multicoating. It's alright on my K10D; nothing special but alright. If you're looking for a 43-150 mm equivalent zoom then the Tamron zoom might be OK at modest enlargements but don't expect too much and do see if you can get a decent returns policy on it if you buy.

Actually, I've come to regret buying cheap zooms in the past and, if I could have my time again, would have spent it all on decent primes even if I had to wait a little longer or buy used more often. The only zoom that I use regularly now, and haven't regretted buying, is the Pentax 16-45mm. So do think carefully before you buy; that £119 could get you part of the way towards, say, a 70mm limited.

Adrian

Wiser words were never uttered.

G

Thanks for the advice.

The equipment is for use in tandem with a 70 -300mm Tamron , for Air Show use. I'm looking for something to stay on the body for static shots but felt the 18-55mm might be limiting due to the constant changing size of the various parked aircraft.

Dont want to keep swopping glass and invite the dreaded dust spots !!!

What do you chaps suggest by way of a " 70 limited "

70 limited = Limited edition 70mm lens, which in 35mm equivalence is about the same as a 105mm lens field of view. The "Limited" lenses are of exceptional quality! http://www.srsmicrosystems.co.uk/index3.asp?id=65&Page=2#