Penny for your thoughts please...

Hi All,

I'm heading off to Axalp in October for Swiss Air Demonstration in the mountains (Examples here ).....

..I'll have my Pentax KM and DA 55-300mm with me but am wondering if I should splash out on something like the Sigma 150-500mm to give me a little more. I wonder if anybody on here has been ?

Now its going to be hard to to find the cash but I could perhaps look at selling some of my older SMC lenses to go towards the fund, primaraly my 300mm F4. I've never used it with my KM but as somebody who doesn't like parting with things would I be a fool to consider getting rid of it ?

I also have a Pentax 400-600mm Reflex Mirror - I never really got to grips with this and its been unused for a good few years. Reading the thread Tamron Mirror lens it would seem its not worth really considering taking this with me as results might be patchy at best especially with little experience of it.

I guess I might just end up sticking with my DA and enjoy the trip regardless !

Sorry for the ramblings !

The K 300mm f4 will be worth good money if you do decide to let it go - they don't come up very often. Personally I'd hang onto it unless you really need the money.

Not been but from a quick peek at those examples you can borrow my 50-500mm if I can come too

Would the 55-300mm work with a tele-converter?

Not very well, and especially not for an air show with fast jets.

Thanks for the quick replies...

Ooops...yes this was another thought I forget to throw in. I was reading with interest another thread regarding teleconvertors. I guess that would probably be the easiest/least expensive way of getting a few more mm but would it be really worth it ?

Mike-P....mmm.....if you can pursuade my partner to stand aside your welcome. It would probably cost me far more than a new lens to calm her down though !

I have a 150-500 and I always have to pull it back to 400-450 and set to ~f7.2 to get sharpness back that is lost completely at f6.3@500mm.
I'd stick with the 55-300 as that is much sharper at 300 than the Siggy.

Secondly the magnification difference between 300 and 500 isn't something to write home about - it's a bit 'yeah so what'.

C

Have a look at my gallery. The two triplanes, the parachutist and the bird are taken with the Sigma 150-500. It is sharp at 500mm but not wide open (good from about F8-F9) and the HSM is the fastest focus I have on my Pentax body.

There is a newer and probably better version available now and it will knock the 55-300 into a cocked hat for aviation photography.

The Bigma 50-500mm may be a better bet if you can find one. For some reason, Sigma never seem to better their first offerings with some of their lenses. The 70-200mm f/2.8 is another example. The Mk1 has the edge. I have seen similar comments with the later x-500mm models stating minor issues. The HSM is a step forward though if the AF speed is improved.

Rogers pic's are great having good light. I couldn't live with F8 or less though in lower light.

Regards

Good point Gary, and one I forgot. The big Sigmas do like lots of light.

To be fair, at an airshow there is usually plenty of light!

I was surprised by how far I could stop down and still stay at 1/2000 for fast jets.

Yeah right.

Now that made me laugh...

K.

I have seen fantastic shots, on another forum, taken at airshows with the 55-300 & a K7, the sharpness of those shots was one of the main reasons I went out and bought the lens.

Someone did a comparison with the 55-300 and all different teleconvertors. Clear winner was the Pentax 1.7x - but then all the others were 2x so maybe a Kenko 1.5x or Tamron 1.4x might be better !

As it stands at the moment Pentax cameras do not have the AF speed to keep up with the very fast jets. Yes you will get maybe 10 out of a hundred that are worth keeping but continuous focus is just not up to the job most of the time and you can count yourself lucky to get that "special" shot when shooting aircraft.

Now put a teleconverter on a f5.6 lens and imagine how much slower the AF is going to be.

Been there, tried that .. when I had the 55-300mm.

The only decent size quality zoom that will take a teleconverter and still have workable AF for aircraft is the Sigma 100-300mm f4 imo.