Originally posted by Jannis I'm thinking about shoting with longer telephoto for a long time. I mean modest wildlife, ZOOS etc... (not safari) I had old FA series 80-200 but sold it. I had also cheapo Tamron 70-300 Macro - but its IQ was very poor on the long end. Then, I have aquired one 50-200 WR and 55-300WR (accidentally) - But, 55-300 was on its long end almost same IQ as at 200mm upscaled - and almost same IQ that is upscaled image from 50-200 on long end - due to that and fact, that 50-200 is smaller and has faster AF, I have kept the DA50-200WR and sold 55-300.
Now, although I´m quite satisfied with my 50-200 when stopped down to f8, I´m looking to improve my telephoto capabilities - so, I have 3 ways (and 3 questions) in my mind:
1) Buy new telephoto lens: If I consider to buy new lens - can anyone compare advantages and disadvantages od DA*200 ($890) and DA*300($1100) (I dont considering DA*60-250, because I have DA*50-135 - so much overlap)
2) What about using new teleconverter($370) with my DA*50-135 - it turns it to 70-189 f/4 - and bonus will be using on my 100 macro to get above 1:1
3) What about upgrading body and cropping? I currently have K-5II and it is really nice camera.But if i get K-3 ( with current rebate it is $920 - but with no extra stuff, no grip, no card... - european prices aren't as good as US deals). This way I get more detailed picture from all my lenses, aren't I? With sufficient resulting power I can get 75-200 from my *50-135? due to incerease in resolution - and maybe more - considering absence of AA filter.
Wich way are you thinking, is best (which has best value/price ratio)?
I cannot considering buying used, becouse I connot find good used deals in EU end buying outside EU tends to be more expensive than new here due to tax and duties.
Thanks for any comment and advices
PS: My gear: K-5II (non s), and my tele lenses are DFA 100 WR, DA*50-135, DA50-200, DA18-135, DA50f/1.8 and old manual Takumar 200/4
PPS
My feeling from your situation.
If you have already a 50-135 and use a lot you 50-200 for your tele need, your easiest update it is to buy nothing, leave the 50-200 home and use the 50-135 for your tele needs. When there need, crop your 50-135.
Here is a 50-135 shoot at f/5.6 (not worse than 50-200 hey !) at 80mm. This is a 100% crop, you can compare it to your hyena or aigle crop. On purpose I didn't do any post processing and removed all the DxO automatic correction. Post processed correctly this is much better.
The crop on K3 give equivalent of 400mm framing:
If you want to see some zoo shoots with it, this is here:
https://www.flickr.com/photos/nicolasbousquet/sets/72157647367764626/ Don't hesite to download/look the full resolution shoots. It much more sharp than your 50-200.
The next logical step if that's not enough is to add the 1.4 TC for very reasonable price.
I suppose also selling that K5-II used and replace it with a K3 would allow for more cropping, a bit like you see here while keeping the current gear. The price and effect would be similar to what of the TC I guess if you take into account the money you would get from selling the K5-II.
Honestly, what you really want from the description other than that is the 60-250. Not a birder very long tele like the 150-450. But a versatile long lense. And because you still use your 50-200 instead of 50-135 (an heresy !!!!! Really) you must be very sensitive to weight.
You fill like 60-250 is very similar to 50-135 but I don't how this would be any worse than a DA*200 or DA*300. That's pure psychology as obviously the 60-250 can do more than theses 2 primes at the expense of a bit lower quality (DA*300) or a bit less light gathering (DA*200). But from practical purpose, this 60-250 DO MORE than the DA*200 and DA*300. It is not much more heavy/bigger than DA*300 and there often very interresting used price for it on the market.
That the 60-250 also cover most of what the 50-135 can do (except f/2.8 really) should not be seen as an issue but additionnal asset. If you don't need the low light gathering of the 50-135, you can sell it to found the 60-250, add a DA50 f/1.8 for almost nothing so you get both better portraits and both better tele reach.
There nothing that will bring as much possibilities as a tele than this 60-250, and on day you can add the 1.4 TC and really have the ultimate reach with very high quality (a 85-350 f/5.6) while keeping something much smaller lighter than a 150-450.
All in all then:
First learn to use you DA50-135, really ! Spend some day at the zoo with it !
Then maybe see if you still miss something.
If it is not much, just a bit more reach/details You can exchange K3 from K5-II or buy the 1.4 TC.
If you still need much longer tele or not, and advise then if 60-250 + TC is really the best compromize. 60-200 f/4 AND 85-350 f/5.6 with great quality.