Yes it is. Will try and get into SRS where I got it from and see what they think.

Had the Sigma 150-500mm for a few months now and it seems to have possibly developed an AF fault. It focuses pretty quickly and accurately up to about 20 metres but anything distant hunts badly. This happens in good contrast situations and on simple subjects like a sign or a distant house. It just goes backwards and forward either side with a sort of clicking noise. In the same conditions the DAL 55-300mm snaps on focus easily. It does this for all AF focus settings and with and without all OS S/R combinations. Every now and again it seems to work normally. I don't seem to remember this problem when I first got it. Any suggestions?

I "upgraded" from the Tamron 70-300mm. That was an excellent lens but not as good as the DAL 55-300mm. The macro was nice though. Trade off with the slightly wider 55mm bottom end. I didn't think they made the DAL any more. The plastic mount has never bothered me and easy to get a third party lens hood. All irrelevent now while that Amazon offer is around!!

I have both the 55-300mm DAL and the Sigma 150-500mm latest version. Even with the price limitation, if I only had one it would be the 55-300. You already have 400mm and 500mm covered for fairly static subjects from hides etc. I find the 55-300mm more versatile for impromtu wild life moments. Mine focuses faster than the Sigma (may be a fault there which needs investigating)and is easier to swing around and point up at trees, bushes etc. Of course a fraction of the weight on long treks. Image quality is similar. This doesn't mean I don't think the Sigma is great - it is and I need and use both. I think all of us wildlife photographers have this same decision problem which is not fully resolved within in the Pentax lens range.
Most of the pics here except some recent ones are with the 55-300mm
http://my.opera.com/dcweather/blog/
Dave

I don't prefer manual focus by Live View as I have to put on my reading glasses but I have tried it and it is very good. Much better than it was on my K-x. Still a bit slow but when magnified as specified above I would imagine very accurate. The advantage I find with a viewfinder is that after focusing you don't tend to move but with Live View, unless on a tripod, you do.

Thanks Greg. Looks better as it has dioptre adjustments. That's some smart looking engineering you've done there. We might be asking for a few other mods.

I would think there are other older users with this problem. I set the viewfinder dioptre adjustment for my long sightedness (reading glasses)and use the viewfinder normally. On the occasions I need to use the LCD screen I have to put on my reading glasses. The ideal although unlikely solution is a dioptre adjustable LCD screen. I've seen these:-
http://tinyurl.com/d5qyga9
... are they any good. I think I've seen an expensive version that does in fact have dioptre adjustment.

What about the DAL version of the 55-300mm? It's quite a bit cheaper.
Dave

As I mainly do wildlife and macro but also anything that looks good it would have to be the DAL 55-300mm and maybe sneak the Raynox -150 in my pocket which it works great with. That's everything covered although I might have to move back a few miles for the landscapes
Dave

Agreed! You can get those clear sheets for putting over news print to magnify it for reading. WOnder if a piece of that would work. Probably not optically pure enough. My old dad used to use one - now I'm old!