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I am after a new lens for my Pentax K100D to replace my 70-300mm sigma lens. I have narrowed it down to the following, prices are in Australian dollars

Pentax 18-250mm DA f/3.5-6.3 ED AL - $665

or

Sigma 28-300mm f/3.5-6.3- $429

I like the sigma cause it goes to 300m but I also like how the pentax starts at 18mm which means I would not have to swap to my 18-50mm for wide angle anymore. Also i assume that the pentax lens would be a better made lens?


Any suggestions??

I have the Sigma 70-300 as well, so I'm inerested in an alternative. I'd be more inclined to have a few lenses rather than 1 that covers all though. The wider zoom range allows more dust to enter the lens and can be inferior to shorter range zooms and primes. It all depends what you want to do as well. I do a fair bit of motorsport, and 300 is plenty for this. I'd even make do with a 200, you can always use a teleconverter if needed. A bit of foreplanning goes a long way - atm I only have 2 lenses, and at a motorsport event I leave the 70-300 on unless I have pit access, then chuck on my 18-50 for that only. I know for what I do, which varies a lot, I'm eventually looking at a 10-20 (or near) faster lens (>2. for landscapes , a fast 50 prime for portrait and street photography, a 70-200 for general motorsport and nature, and when the budget will stretch, a 300 prime. In dreamland this would be on a Canon MkIII and be all L Glass lol...

But really, let us know what you want to shoot mainly and we can provide better advice.

Hi I did a lot of research on this recently myself and talked with a few different people that had both Pentax and Sigma lens's in this range.

I would definately stick with Pentax.

The advantages of Pentax over Sigma are as follows.

- Sigma lens owners report that they tend to creep.
- The end of the Sigma lens rotates as it zooms. This can be a problem for some filters.
- You can not touch up the focus manually in automatic mode on the Sigma lens like you can with the Pentax.
- The Sigma lens takes different sized filters.
- The sigma lens is heaver and longer.

The SMC Pentax DA 55-300mm seems to be the pick of them in the more budget range. But you will loose the 200-300 macro ability that you currently have with your Sigma 70-300.

You are also back to having to swap lens for close shots.

This said though you don't get the wider ranges without sacrifice.

I myself would have preferred the 55-300 but couldn't afford it so had to settle for the 50-200 as a temporary stop gap.
.-.-.

I guess a lot will depend on the Quality you want... generally an all purpose lens gives you average quality
I mainly use the DA12-24/4, DA*16-50/2.8, DA*50-135/2.8, FA*300/4.5 and FA100/2.8 Macro

I do have quite a lot of lenses to choose from but these have become my take everywhere kit.

there is a new DA*60-250/4 which promises to be a great one and with a price to match its perceived quality.