Mike P after much thought & even considering both lenses, I've decided to go with the 150-450.
If my images end up anywhere like yours I'll be happy.

Thanks for the recommendation.

Excellent images Mike and am impressed with the last one which had a converter on too.
Yes, I'd be more than happy if I can read the writing on the aircraft.
I have found I get a far higher % of sharp images with the Pentax lenses than the Sigma even though it has produced some that I'm really pleased with.

Yep that's sharp alright! Excellent set of images.
I thought my Sigma 50-500 was good until I started using the Pentax 560mm - the image is outstanding. But I was making people duck last week when I was using it!
I'd rather not use a tripod for aviation as find it restricting but it's ok with sports I find.

Thanks for that. Yes I saw their prices were higher than SRS. Maybe I'll try that.
Having seen Mike P's images, the quality is certainly very good on the 150-450. The 2kg weight is an issue though if hand held.

Thanks for that Mike.
Yes, I would've thought the 150-450 would be an ideal range for aviation but do you find the weight an issue?
I know someone posted before on another thread that he found some images he'd taken at 450mm disappointing because they weren't sharp.

Am in Plymouth so getting to SRS is a bit of a trek. I've thought about hiring them although it seems they don't hire out the 150-450.

Maybe I should keep my fingers crossed that Pentax will soon bring out a 400mm lens.

I don't have a decent Pentax dealer near me so buy my kit from SRS.
Am going through my shots taken at Yeovilton using the Pentax 560mm and Sigma 50-500mm. 300mm images would be small 🤔

Hi, I don't wish to repeat what has been posted before but any advice would be welcome. I use a K-3.

I've read previous posts regarding the 300mm or the 150-450 and am in the same quandary myself at the moment. I've recently bought a 560mm and been very impressed with the excellent image quality & now thinking of adding one of the others for sports, aviation & wildlife. The 560 while great is just a bit too big & heavy for aviation for me.

I'm told that the image quality of the 300mm would be better than the 150-450 & it's lighter too which helps, but obviously being able to go up to 450mm would be better for the subjects I shoot. Yet am concerned about the extra weight when trying to use hand held and also if there is a reduction in image quality - provided I can hold it steady!

Many thanks

I like them. Very good

Jon,

Thanks for that. I'd better just defend the magazine a bit by adding they did still recommend the K-7 & maybe as you said the sample photos they displayed weren't taken in a suitable mode.

They suggested they would look ok after using Photoshop but I must admit I'm not keen on doing it that way but would rather be happy with the image initially.

I like the idea of it being more compact too.

Thanks for the advice.

Gordon