Sigma 100-400mm HSM in Pentax mount?

I suppose It really depends on what you are shooting and how you want to frame the aircraft. The K-3II is a crop body and gives you more megapixels on the subject when compared to the K-1, it also has much faster FPS and a larger buffer. As you have found out lens length is usually everything with aircraft and a 23mp crop body gives you more than a 36mp full frame body which is roughly 15mp in crop mode.

But as I said, it depends on how you want to frame the plane to start with, most airshow shooters tend to do it like this when photographing single aircraft and that was 450mm cropped hard. (BTW I recently sold a 1.4x Pentax TC for £220).


RIAT 2015 by Mike.Pursey, on Flickr

Unfortunately you won't find a teleconverter that will work 100% with Sigma HSM lenses so that is a non starter. I get the feeling a 150-450mm is a bit of a stretch financially so I would look at selling the K3II for either a used Sigma 150-500mm or (ideally) a 50-500mm.

Have to say though the K3II is a lot more suited to airshows than the K1.

There is a new lens roadmap at the bottom of the page, looks like the DA* 11-18 f/2.8 has been put back to at least 2019.

Sample picture look excellent ... looks like Pentax have made an effort this time.

I once purchased a used Sigma 70-200mm f/2.8 off Ebay and when it arrived the pictures were so soft I presumed it had been damaged in some way. Then I realised there was a thin filter on the front (quite an expensive one from what I remember) so before opening an Ebay dispute I tried again with the filter off. It was honestly like night and day so I have never used a filter since and tbh where macro is so detail critical I wouldn't use anything apart from the hood.

Personally I use the old shutter speed vs focal length calculation, anything below I use SR and anything above I switch it off. I do find that at high shutter speeds having SR on gives me less keepers when doing an air show.

Grip sold subject to payment.

Well personally I think you should contact the insurance company and tell them you found one for half the amount that they paid out. Also, seeing as you kept the insured one and it has come back to life I feel you should send back say 65% of the insurance payout ... just for peace of mind

Well done anyway.

I will send you a PM