Better than 55-300mm?

My "dilema"...
I'd like to get a lens on the tele side (300mm+).
I currently have the 55-300mm which is a great versatile lens but just doesn't satisfy me enough on the tele end.

I need some advice on the options I contemplate, and if my views are correct. Basically, an assessment of my assessment

If I make a sacrifice on gear (might include the 55-300mm) I think I can afford the following options (used):
1. 70-200mm F2.8 + 1.7/2x TC
2. 300mm F2.8 Adaptall2 + 1.7x tc
3. SMC-A* 300mm F4
4.One of Sigmas large zooms:
135-400mm, 50-500/150-500/170/500mm
Less pricey alternatives
5. Tokina/Sigma 400mm F5.6
6. CZJ 300 F4 M42
7. Pentacon F5.6 M42

Numer 1 would give me a great lens for medium tele, but longer tele only with a TC, which decreases quality and F stops. Should still give great results. But this might be the priciest option.
I like this option because it also leaves room to grow without redoing the gear.

Number 2 might be gotten a bit cheaper than 1, provides a very fast 300mm, but a "semi" AF >400mm lens. It'd be ok for stationary subjects, harder on moving ones. Loss of intermediate AF zoom (I have some primes might not sell).

Number 3, great lens, A version for ease. But is it better than the 55-300mm? Not sure. This would be cheaper still, especially if I don't go for one in pristine condition.
F and FA versions too expensive as they are uncommon.

Number 4, with the flexible and far reaching zoom, it would be a good alternative although not very portable. Quality would be about the same as 55-300mm, but only for the later versions, which I might not afford...

Number 5. There are MF and AF versions, both affordable, keeping the 55-300mm if its the MF version. Quality wise I'm not sure they'd be woth it...

Number 6 and 7 I can make it, but is it worth it for the IQ they have? Not high on my list...

It would be nice to get some feedback from users of one or more of these alternatives.

I use a 70-200 Sigma with 1.4X TC and am very pleased with it on my Pentax. IQ will not be an issue with a matching TC. I also use a 70-200VR with its matching 1.7x TC on another system and it also is very good.

The system is versatile.

I do want a 300mm f/2.8 but that is not for my Pentax kit.

Regards

Do you use to shoot wildlife or sports?

Mostly sport, but I prefer the flexibility of the 70-200 lenses. The 300mm will be for same.

Not too much wildlife about over here.

What are your subjects.

Regards

I have used a few of those lenses (and still have a couple myself) but personally I would push the boat out a bit, go here and haggle with him on the Sigma 100-300mm f4 and 1.4x teleconverter. A perfect match, the lens is superb on it's own and pretty damned good with the 1.4x. This lens would be one of the very last to go from my kit.

I know its a cracking lens, but that is a bit too rich for me Mike...
Even what I propose is not for immediate purchase.

In that case I would say the Sigma 70-200mm and matched 1.4x teleconverter is better IQ wise than the 55-300mm (infact even the 70-200mm and matched 2x is better) plus you get the bonus of f2.8 if used on it's own. Only thing I would say is don't buy the newer HSM or macro versions but start looking for the older APO EX lens.

Any experiences with the tele-zooms from sigma? I know in the shorter end, I'd be getting a worst lens, but they have good reach.

Scott used the 70-500mm to very good effect when he was here. I have the 50-500mm which is not bad at all wide open at 500mm on my K10D but I should imagine they would be a lot better on a newer body as you can push the ISO further. I used it at our local airshow last year and it performed very well considering the changeable weather. I think Oggy has the 150-500mm which he also rates and that has HSM as well. The 50-500mm is actually ok at the shorter end.

I have an old Sigma 400 f5.6 manual focus and it's very soft.

Yes, there are apparently 3 version of that Sigma and only one is good. Dunno if its good enough though.

I can't advise at all on the other lenses, but FWIW I've just got the Sigma 150-500 HSM . Having a whale of a time with it. Image quality is decent, but not exceptional. Definately lacks contrast - but that is correctable in GIMP/digiKam. I even put a Kenko 1.5X TC on it and the manual focus was really quite simple and precise (though it loses the red spot when in-focus for some reason and focus tends to drift). It does have some noticable CA at 500mm but again that is correctable with decent RAW converters.

Really looking forward to using it in bright light with less contrasty targets as I think it'll shine there.

C

Sitav is selling 100-300 + TC here.

I do indeed get on well with the 150-500. The only reservation I have is not wide open at 500mm, so it likes a bit of light.

Chris
"(though it loses the red spot when in-focus for some reason and focus tends to drift). "

Did you know the red spot indicates what is being focused on. It's the Green hexagon that goes steady when the focusing is correct according to the camera.

Sorry - I was truncating for brevity. Yes I know the hex shows being in focus, but the chosen focus point should flicker red as well. The full symptoms are:

Without the TC and Manual focus enabled: red focus position flickers on then off (as I'm used to) and green hex is shown.
With TC and Manual focus enabled: red focus spot never flickers on and off when in focus and green hex not shown.

C