300mm lenses

Good evening everybody!
I've been recently trying to buy a decent 300mm lens for my K20D. Ordered Sigma 100-300/4, tried it very briefly and decided it's not good enough for the weight and the money. Unfortunately, I didn't have much time to play with it so maybe I was wrong. Anyway.
Got A* 300/4 - it's definitely soft (!), full of chromatic aberrations and purple fringing. So, here is the first question: is it just a bad copy or inherent problems of the old design? I just might be spoiled by the modern Pentax primes.
Tokina 300/2.8 seems to be an outstanding lens, but I don't think it is available in Pentax mount. Sigma 300/2.8 might be another excellent choice, but it's much more expensive. Then, my choice is between second hand MF Tamron 300/2.8, same in AF (for some reason Photodo gives it much lower scores) and the new Pentax 300/4. I know very well the difference in weight, SDM, coating and so on. Talking just about the image quality, can anybody comment on these three? Or advise me on another choice?
Thank you in advance.
Maxim

P.S. I'll post my pictures with A* 300/4 later.

SMC Pentax-DA 55-300mm.

Inexpensive but excellent.

Good for the money, but I'm afraid if sigma 100-300/4 was not good enough in terms of image quality, this one surely will not be better, although it will be better in _quality for the price_ terms.

Ah, but how do you know that if you haven't tried it?

How do you know I haven't tried it?

Sorry to bring it up again, but it looks likely that my A*300 f2.8 may be looking for a good home. I have heard no more from the prospective purchaser. I can assure you that this beast is sharp.

Richard S

That's how I know you haven't tried it, because you told us.

It must be my "not the best" use of English that gave you wrong hint .

And may I ask you how much would you ask for the 300/2.8 A*? Also, after this disappointment with A* 300/4 I am a bit cautious. It gives an impression of a classic soft portrait lens: soft image superimposed over a sharp one. Shooting squirrels in the backyard I can see every hair, but a colored halo around as well, kind of a dreamy look. Shooting tree brunches against cloudy sky gives me green silouettes behind the focus plane, purple in the front, and plain purple fringing around the edges in the plane itself. I guess, since the underlying image is sharp, there is no damage to the lens but rather the old design with less-than-perfect optical correction. Overall, I have to say, to my very big surprise and disappointment, it's worse than Sigma 400/5.6 APO Macro I've gotten from ebay for $150 6 years ago. I used to use the Sigma all the time on istD, for kids, animals, birds flying by (!) on the beach and it was definitely better. I got tired of 5.6 though.
So, can you post some pictures taken with 300/2.8? I am new to this forum, I don't know if there is an option of sending personal emails, but I've provided one with my registration, so if you don't want to make anybody read our personal communication here, we can switch to regular e-mail...

Max, have you eliminated possible AF problems with your "soft" lens by trying manual focus bracketing (repeated attempts with small manual adjustments of focus), or trying AF Adjustment if K20D? (Preferably using a tripod).

I can't offer any specific advice on 300mm F4 or F2.8 lenses. Such long lenses of that speed are out of my league and in my dreams only!

I have the DA*300mm and it's beautiful. Sharp from wide open. Highly recommended.

I used to have the old Tamron AD2 300mm f/2.8, and while it was a great lens, and was very sharp once stopped down a bit (and if I got it in focus), it did suffer from aberations, purple fringing etc. The DA* does not.

Some pics here. Note the bird pics are handheld (something I wouldn't have been able to do with the old Tamron) and shown at 100% and cropped down, so pixel for pixel. Great detail, just a lovely lens.

Did I mention I like it?

Dan

A* 300/4 is a manual focus lens to begin with. Yes, I do have problems focusing but since I shoot 3D objects even if I miss a perfect focus on the squirrel's eyes I can still identify the perfect focus plane on the body and pixel-peek the fur. And it is less then perfect, as I've said.

Daniel, thank you so much!
Now, a stupid question: how do you upload these beautiful pictures?
Thanks,
Maxim

See https://www.pentaxuser.com/forum/topic/How-to-Post-Images-6624

Sorry I didn't have my brain plugged in regarding my comments on AF.

Maxnovikov, Will send PM later today. Off to work now

Richard S