Hi, I don't know anything about Serve on, but i am on the fire service here in Ireland. As it seems to be night training, light might be your biggest problem, they will most likely have lights set up so they can work but they may hinder you at times also, a tripod might be handy for some shots and external flash if you have them, the service guys or gals will probably be delighted to have someone there taking photos. See if you can speak to the station officer about what and where he will let you go, he / she may want you to remain a certain distance back depending on the training that they are doing. We are usually an approachable bunch and are used to having an audience while we work.
Good luck on the night and let us know how it goes.
Derek

The hd 1.4 seems like a super tc, and if I do go down a tc road that's probably what I'll get. I got some interesting results when I Googled that pentax a2xs halfway down the 2nd page before it came up for the tc, but it does seem worth looking at or for as well maybe, depending on the price.
Thanks for all your help guys.
Derek

As ever they're all good, but no 2 is super. Love them.

Well worth the early start. Nice shot.

It will be especially tough to justify it when you consider that you could have the tamron and a new K3ii for the same money. I'm sure it will be fantastic, but I couldn't justify it.

These are from a short walk down by a river in the village next to ours. It was fairly frosty but the light wasn't bad overall. I was surprised by the variety of birds i saw, and i enjoyed the walk.
K5iis + tamron 70-200mm f2.8
All fairly heavy crops

Are there any 1.7 that are worth looking at or does iq just drop too much ?

Hi Mike, i knew you had one and really rated it highly, but on closer examination the one i was looking at is an older version than the os version. Sigma 50-500 F4-6.3 APO RF is the one i had seen and the fella seemed to be up for some sort of trade against the tamron 70-200mm.
From what little i could find out about this version leads me to want to avoid it.
Pity as the reach and Iq from the os hsm one seems pretty damn impressive.
Derek

Or would the 50-500mm ex be a better option. I don't shoot wide open, usually about f8.

Is there a 1.7 tc that's worth looking at or does the iq suffer ?