Need more reach - what to do?

Shot some plane images today and the longest lens I have is the Sigma 70-200mm HSM. Found I was lacking the reach and cropping images heavily.

I do own the 1.4x Pentax rear converter WR but it doesn't like the Sigma 70-200mm and won't focus when trying to use them combined. It just won't focus, end of.

Debating to get more reach do I, sell the 1.4x WR converter on and buy a good T/C that the Sigma and K1 combo likes or, do keep it and see if anyone wants to swap a longer reach lens in for my spare K3ii body?

What would you do?

The ideal is the 150-450mm, but it's heavy and expensive. Failing that, how about second hand?

I have a 150-450mm available for sale here should you be interested. Some of the jets in my portfolio were taken with the lens.

Al

Vo7ch for both of these, yes heavy and expensive but a superb lens, a lot of my mach loop stuff is with this lens, with the K1

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.

How does the DA*300 work with the K-1? Not sure if it is a viable choice.

Regards
David

Or what about this? link

Regards
David

Yeah after investing in full frame and completely overhauling my gear I'm on a budget now so the 150-450mm is nice but way out of my price range right now.

Bad timing as the Sigma 150-500mm that sold recently through the classifieds/eBay was in the right price bracket for me.

Can I ask why the K3ii is better for airshows than the K1?

So, probably best to sell the 1.4x TC on then as its not going to be compatible with my lenses. Now to look at what they go for?

Bit much for me at the moment

What about the Pentax FA 80-320 or FA-J 75-300 - both can be had for well under £100 and although they don't have the ultra fast aperture, and may not be the sharpest at the furthest reach - they can both deliver some very good results - probably stick to about 270mm as your max and you may be pleasantly surprised :

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

The DA*300mm works perfectly on the K1. It is a FF optical design and as such there is no vignetting when used in FF mode. It is an old design as far as the FF motor is concerned so wont be as snappy as the newer D-FA lenses, but it is a great lens.

Could always go old school with a A* 300mm f4 manual focus though.
https://www.pentaxforums.com/lensreviews/SMC-Pentax-A-Star-300mm-F4-Lens.html

Could be had for something closer to your budget. Or is AF a must for airshows?

Have you thought about the pentax 1.7x afa converter. I used this for a long time with my FA*300 F4.5 and regret selling it to buy the DA 1.4x. I don't know how familiar you are with it but it will give AF over a limited range, basically you set your lens to Manual focus (which I assume the Sigma can do?), pre-focus at an approx distance and the afa converter does the rest. It would convert your 200 to a 340 F4.8. You'd probably have to stop down the lens a bit to get the best sharpness. I've never used it with the sigma but used to use it with a Tokina AT-X 80-200 F2.8 manual focus lens and it worked pretty good on that. Also I know it used to work with old school full frame as it was designed in the film era and worked with my Z1 and Z20, so assume it will function ok on the k1? Perhaps others will chime in if this assumption is wrong.

With my dodgy eyes I need AF!