If you have desribed the two lenses correctly then to compare the CAMERA AF speeds is like comparing apples with stage coaches !
The Sigma 70-300 has a simple screw drive AF whereas the 70-200 (costing around 8 x as much !) has the HSM fast motor driven AF.

If you do, indeed, have BOTH lenses then it would be instructive to compare the AF speeds with the lenses and cameras the other way around ?

Just a thought ?
Peter

No, I would guess hat a DAM lens is a Manual focus Automatic aperture Digital only lens ?

Peter

As far as I'm aware NEITHER the Sigma 18-250 nor the Pentax 18-270 have weather sealing ?
That's why I'm currently using my Pentax 18-135 !
This is an expensive lens to buy 'on it's own' but was a bargain when bundled with the K50 !

Regards
Peter

That is very true, John.
However, when I got my Sigma 18-250 it was half the price of the Pentax 18-270 and all the reviews, of both lenses, I'd read left me in no doubt which to get.
The Pentax lens is now much lower cost but still almost twice the price of the Sigma with cashback ?
I can only add that everyone needs to evaluate as many reviews as possible in the light of their own needs and preferences and then make a choice - at least there IS a choice !

Peter

No problem - simply click on my name 'PeterKR' on the left of this posting and it will take you to my page where you can click on 'Portfolio' to see my pics or send a Private Message. Try clicking on your own name to experiment ?
You can look at anyone's pictures and send messages this way.

Good luck, and never be afraid to ask questions !
Peter

Sigma make a 18-200 for Pentax but the lens you should get is the latest 18-250mm which SRS have for the bargain price of £249 after cashback !
I paid around £320 for mine in late 2013 and it is such a good lens that it stayed on my K-r ALL last year.
(It is STILL there now as I got the K50 +18-135WR kit last Autumn so during the inclement weather THAT is my carry around kit !)

If you want some proof of the versatility of the Sigma 18-250mm lens just look at the 2014 pages on my Portfolio.

And by the way, in answer to another of your questions I use Class 10 8GB or 16GB HCSD cards for saving both RAW and JPEG images. I prefer to use the 8GB cards as there is less to lose if you lose one but 16GB cards are so cheap nowadays that I gave in !

Good luck
Peter

I agree, lovely crisp images.
However, I didn't realise that Morrisons had there own trains !!!

Best regards
Peter

I agree with Nigel.
Scenes like this always beg to be shot but the problem is chosing the point of view ? As Nigel said, it is worth experimenting with getting several shots from different angles including low down and close ups.
There is a lot of information in there and it possibly needs something to concentrate the view ?
I had a similar dilemma recently and this is what I did :-



Whatever, you have captured it well with good exposure and sharpness.
Just keep on trying different things.

Best regards
Peter

There are several different versions of the Cosina 24mm F2.8 but there is a review here :
http://www.pentaxforums.com/userreviews/cosina-mc-cosinon-w-24mm-f-2-8-24mm.html

Best regards
Peter

I've just had a mail from Serif offering PhotoPlus X6 for £9.95 !
(But the link is specific to me as a Serif customer !)

I have PhotoPlus X4 but hardly ever use it since I got Photoshop Elements 11.

If this posting is a follow up to your posting about RAW files then I'd avoid PhotoPlus and bite the bullet and go for Photoshop Elements as it is far better at developing RAW files ! (Well that's what I have found !)

The latest version of PSE is 13 and it is currently around £65 on Amazon but keep watching as it usually comes on offer for around £30 -40, especially as the bundle with Premier Elements (which is how I got it).

I've seen copies of PSE 11 on ebay for around £35 ?

My first efforts on RAW processing were with PDCU4 which came with my K-r but that is NOT easy to get to grips with. Also, it is camera specific and won't handle the RAW files from my K50 which comes with completely different software - which won't handle the K-r files !!!
PSE11 is happy with them ALL and much more intuitive to use.

Good luck !
Peter