[trishytee]

Cripes Tommot how many lenses do you have. I have been checking out the first list you gave me, now you have sent me back to the drawing board. Reviews just confuse me more as they are all good. So you love the Sigma? Would it be Ok for the wedding pics do you think. Keeping in mind I wouldn't need too much zoom as I would use my other zoom for any far shots. I think I am actually going to take your advise, but now that we have moved on from the 17-70 lenses and to the 17-50 or 50-135 I think it might be the Sigma as I don't need to start on 50 and the Sigma sound about right. Your final thought? I lost half the price of a lens last night!!

[trishytee]

Just wondering Tommot, as you seem to be the lens guru, why would the 17-50 cost more than the 17-70? I have been looking at prices and the latter is a lot more than the former.

[Tommot1965]

Trish

The Casino can be cruel sometimes....best to just have a meal and a drinks...:}

as far as lenses go...Ive not owned a DA*50-135..or a DA*16-50 ..but from all reports they are stellar lenses, with the 50-135 being the pick of the two...

again I do think you will have to answer what Focal length is important to you , no one can do that for you...

.as an example..I owned the 16-45 Pentax...I really thought what he hell do I need 16mm for !, but after having the lens for a month or two..I found that I really cant do without the wide end. so my new lens had to have at least 17mm...and once you want F2.8. the zooms are all in the 17-50/16-50 mm range

to get a greater FL. and still retain 17mm, you will have to go to a F4 lens..



heres two example shots with the Sigma 17-50 F2.8 OS after some PP { post process } work











so after all that...17-50mm is great for tight spaces as it has great field of View {FOV}...but you do have to get in tight for a head and shoulders ,

[trishytee]

Yes that is lovely and sharp; she's pretty too! I have been sifting the net and some really good comments on the sigma. though as above I'm not sure why the 50 should be so much dearer than the the 70. Seems to me if you have more lengh you would pay more? Or is it that the 50 is better glass. I intend to get this lens next week so looking for the best value for my money (especially now that Packer has taken some). the 70 is more affordable but if the 50 is better I shall go for that. (Oh, was the red bike taken on 2.8 as well) Nice bokah on the first pic. Been dying to use that word.

[Tommot1965]

the Bike was at F6.3 for some reason, and that reason would be me knocking the rear wheel on my K5 and not noticing..LOL

the others were at F2.8

the reason the 17-50mm costs more than the 17-70 mm is the constant F2.8
all the constant F2.8 lenses have a limited FL over a constant F4 lens , or a variable F3.5-F5.6

also the reason the Sigma 17-50 OS is more expensive than tha Tamron..is the "OS" part..not that pentax owners need that

if you want 70mm at the long end and a constant F2.8, the wide end will start at around 28mm

a Tamron 17-50 will set you back $520 delivered from the states, and you'd have it within a week..
The sigma can be had locally for the same price as any overseas deal..However, if you don't take advantage of the overseas/grey import price matching you will pay around $800 locally for the sigma

[trishytee]

I told you I was dumb, what is the overseas/grey import price matching? And last but not least do you think the Tamron17-50 is as good as the Sigma. Then again if you did, you would have got one!!

[Tommot1965]

grey imports are when you import it yourself , or buy from a Non Australia Distributor supplied retailer......buying from a Online overseas shop is considered Importing the item yourself..

Yes I do believe the Tamron to be as good as the sigma in IQ and sharpness...from the example images I've seen..there have been reports of some slipping beneath the quality control, and being returned for a better example.....Id have to say that the Majority would have been fine straight off.
Im not sure if the Tamron in Pentax mount has a internal Auto focusing motor though..the Sigma does.

why did I buy the sigma....Id read a lot about it..seen example images and read reviews..and the shop I was in..had one there..so I bought it :}

if you wanna save some cash...and are not concerned about AF motors ...go the tamron ..build quality may not be as good as the sigma..but the taken images are