At 450mm I would say Pentax has the edge but add the 1.4x to get 630mm and the Sigma pulls slightly ahead, also the Pentax AF really begins to hamper things. Trouble with the Sigma is that it's over 3KG and using that handheld at an airshow all day is no fun that's for sure. I recently purchased a Canon 100-400mm MKII to try and that is very impressive although 400mm is really the minimum for airshows these days as they are flying further from the crowdline.

Sort of tempted to buy a Nikon D500 and a 200-500mm to see how that compares but if I do then I'm going to have to start getting rid of something very soon after.

I had a Sigma 70-200mm, 85mm and 24-70mm mount change plus Sigma paid for Pentax to fit a new front to the K-1 all for the price of postage to them. They didn't even ask if I was the original owner (which they normally do for repairs under warranty or firmware upgrades).

I did ask how long they would honour the offer and they said it depended on Sigma Japan.

I would be really worried if the K-1 couldn't keep up with a Herc ... I imagine even my phone could do that.

Second one is great, do wish it could be displayed larger though, it makes a huge difference when viewing photos.

Go on, you know you want to. After all you can't have bought anything for at least 12 hours

Just a quick comparison for you. Pentax K-5IIs vs Canon 7D MKI so both older cameras now but were of the same timeframe.. The Pentax shot is actually a little sharper but it was shot at f/8 whereas the Canon was f/6.7

Nothing in it at the time really

Pentax K-5 II s and Pentax HD D FA 150-450mm f/4.5-5.6 ED DC AW



RIAT 2015 by Mike.Pursey, on Flickr



Canon EOS 7D and Sigma 150-600mm Contemporary


RIAT 2015 by Mike.Pursey, on Flickr

You should post some of your recent B&W portrait shots taken with the K-1/60-250mm on here Peter, they are excellent.

I have only just got rid of the 250-600mm because of the weight so I don't think a 600mm f/4 prime is going to make me want to lug another one around despite how good it may be.

If I'm honest as well, the value of something that old worried me, had something seriously gone wrong with it I could have been looking at a very expensive paperweight.

Says manual focus under the lens item specifics but I would imagine thats a mistake otherwise he would have mentioned it in the listing itself ...... wouldn't he?

Seriously tempted by that ..... a very good price as well.

£45 incl UK Postage.