[VoiceOfReason]

Here are a few handheld examples from the 150-500:

Other than the moon crop they're kinda big...

http://www.scottyspot.com/fullsize/008.jpg

http://www.scottyspot.com/fullsize/025.jpg

http://www.scottyspot.com/fullsize/028.jpg

http://www.scottyspot.com/fullsize/062.jpg

At least I have a decent bandwidth allowance.....

I bet I could have done better with a tripod and remote because especially on the 500mm end it's jittery. Mine is the older HSM and no OS version too.

[VisualDarkness]

I got the Da*300/4 too and since I got it the 150-500 sadly finds itself at home most of the time due to the ease, size and WR combined with the sheer optical qualities of the 300. That lens is a small monster and it doesn't take anything away from the 150-500 as it's half the price and has longer reach. I actually haven't used my Kenko on the 300 but as it worked great on the Sigma I expect no less.

[VisualDarkness]

That's quite understandable, and that's why I tried to qualify my reply with "for me" statements. I like shooting birds, which require heavy cropping, no matter which lens you use. I was disappointed in the 100% crops, as I was with 100% crops from my 55-300. My current lenses, the A*300 and DA*300 with 1.5X Kenko TC meet my expectations.

I understand your opinion and reasoning and yeah, I agree with you in case of the cropping. Though the Sigma is often half the price of the 300 used and I didn't count in the teleconverter which can cost a bit too. Judging by the budget of the OP I would say that the Sigma is a great choice.

[gooseta]

I usually shoot at 400mm, and I don't plan on using a TC. I still have my Tamron 200-500 for sony, which is a beauty, for sale. It hasn't shifted yet but if it does I should have another £500-600 to spend, when including that budget increase what would you recommend? I can pick up an FA*300mm for around £600. I don't want the DA*300mm as I don't see any iq difference between it and the FA*.

[gooseta]

i am seriously considering the 150-500 if anyone has any objections.

[VoiceOfReason]

I say go for it!

[VisualDarkness]

Do you have a steady tripod and something good to carry the lens plus camera in/with? I can carry the setup hanging in the lens tripod mount with my Black Rapid strap without any problem.

[Saxplayer1004]

The optech sling strap works very well for me. Have one of the loops on the tripod ring and the other on the body and it holds it quite well. I'd definitely say go for it. Even though mine doesn't get used all that often, when I do use it, it is almost essential

[gooseta]

I will be using a black rapid, I don't usually use a tripod for my airshows as I find I prefer the maneuverability of handheld.

[gooseta]

anyone have any thoughts on the sigm a120-400? Would this be better for use at 400mm?

[VisualDarkness]

Probably not as sharp, most zoom lenses loose sharpness in the long end.

[gooseta]

ok, any other suggestions at £1k?

[VoiceOfReason]

I'd go for the 150-500, but get a new one since it has OS in the lens, and from what I hear that means getting usable handheld shots at 1/30 of a second by some people at 500mm! Just make sure to turn off SR when using that.

[gooseta]

I'd go for the 150-500, but get a new one since it has OS in the lens, and from what I hear that means getting usable handheld shots at 1/30 of a second by some people at 500mm! Just make sure to turn off SR when using that.

I heard os isn't as effective as sr. Also, are there better more expensive options?

[VoiceOfReason]

OS is less effective at shorter lengths, but better at longer lengths. SR really isn't that good at 300-500mm from my experience. You could always go with the newest Bigma, or, better yet, if you REALLY want awsomeness (and are prepared to pay through the nose) the FA*250-600 f/5.6, which is my dream lens. Still, the 150-500 gets pretty good reviews.