Certainly is a difference.
For another comparison this is my latest shot using 150-500 OS @440mm;
Taken 5 days ago so not quite full, you can see some Earthshine on the rim.

LOL, I was waiting for you to say DA*50-135, your Sigma is certainly delivering the goods.

Davex.

At it`s current price you will not get anywhere near 500mm with any other option, where are you based? if anywhere near Chester am happy to let you have a play with mine.

In test`s I have tried the lens OS is a good as my K5 SR.
I know some folks may shout at this, but TBH I frequently leave them both on, does not seem to make any difference, have not found any observable evidence that they may cancel each other out, as alleged by others.



Davex.

Do a forum search, you will find lots of very happy owners, including me.
At the current prices it is a steal.

Davex.

A cracking set, the 4th one is particularly good.

Davex

Agree with Andrew, very strong portrait well posed.
Also quite like the one before it, the shadow from the nose adds interest, although am sure some critics might argue differently.
Good smooth backgrounds in all of these, none of them intrude, apart from perhaps the first one.
What lens did you use?

Davex.

I think Sigma do a 500mm f4 in K mount, arm + leg gets the lens, then you need both kidneys to get the tripod and head to use the thing.

Davex.

TBH do not like the 1.7x af
Tried one for a few months, never realy got on with it,I am aware of it`s perceived desirability in Pentax world, but as i say not for me.

I have a 1.5x (cannot remember all the letters) that works well with SDM and screwdrive, it even works with my 18-135 WR.
Will pair that with the 300mm when I decide what to go for, atm I do not need weatherproofing so the F* is favourite, however will know next week if I am going to spend some time in a tropical rainforrest, if so then the DA* will probably be required.

Davex.

Anybody able to offer a direct comparison of above?
Am aware of the differeces in weight and weathersealing, but how do the different focus mechanisms compare?


Davex.

My brother used to service ejector seats for the R.A.F. It`s only when you see video of one in action that you truly understand just how powerfull they are. A real shame, whatever the reasion it seems like such a tragic waste, hopefully the enquiry will prevent a future occurance.

Davex.