Birding lens

I have had some good results with the SMC DA 300mm with the 1.4 teleconverter with my K5. I have also had some reasonable results with the 400-600 reflex zoom. Hope that helps

Michael

The Sigma 150-500mm would certainly be your cheapest option/ only option to get to 500mm. Lots of people rave about the DA*300mm which they say works well with the 1.4 teleconverter.
I have the Sigma 150-500mm bought new and used on the K-7, K5 and now the KP. I had to send it to Sigma UK and they updated the firmware FOC so the lens would work with the KP, I can't say if it would work with the K3III. Sigma UK were very helpful, I'm sure they would tell of its compatibility.
To be honest I hardly ever use the 150-500mm and probably ought to sell it to someone who would use it. If you decide to go Sima direction I'd happily talk about selling the lens.
Nigel

Stay on Brand -these lenses are stunning on a cropped sensor and the DA * lenses are fantastic even with the Pentax 1.4 teleconverter

1. On a cropped sensor the DA* 200mm effectively becomes a 300mm
• With the TC mounted it becomes a 420mm


2. On a cropped sensor the DA* 300mm effectively becomes a 450mm
• With the TC mounted it becomes a 630mm

• This lens is without equal in it’s price bracket
I have used equivalent Nikon, Canon and Sony on BIF

The Sony is the nearest to the DA* 300mm and the DA* 300 is a very useful close-up lens for insects and other small subjects (good examples in my portfolio)


3. On a cropped sensor the Pentax HD D FA 150-450mm becomes an equivalent of 225mm- 675mm

I don’t find it useful to mount 1.4xTC with the 150-450mm

Any big Canon L series lenses!!

Sorry.... couldn't stop me idiot gene there!

I have gpt some good images with Sigma 150-500 in my K5ii.

Being honest.... coz the buggers are unpredictable, get the fastest lens you can!

i am not a birder but you cant go wrong with a sigma ex dg 100-300 f4 with or with out a pentax 1.4 aw tele
result are superb

I use the Pentax 150-450 for birds in flight, but, with such a heavy long lens, I also use a monopod. I "suffer" from a condition called "essential tremor" (don't know why it's called "essential"), so I need every liittle thing that'll help stabilize the thing. Shake reduction is'nt worth much on such long focal length

Another vote for the DA*300mm f4 + 1.4 teleconverter (can't comment on the other lenses as I don't have them). The reason I chose this route when wanting a lens for birds was hearing a talk by a semi-pro bird photographer. He had spent years using huge, heavy, long tele f2.8 lenses with film. Having made the change to digital and realising that he wasn't getting any younger, he found that 300mm + a TC gave him all he needed in reach while the high ISO cabability of digital let him get the shutter speeds he needed from an f4 rather than breaking his back with an f2.8. My back has been grateful for his advice! And as Daronl says, it's also very good for butterflies and other little things as you're far enough away not to disturb them.

The DA*300mm can be a bit slow to focus at times but is otherwise very, very good. It also works wth the F 1.7x autofocus adapter which gives gives a bit more reach but AF is then handled by the adapter, which requires different focussing technique.

It's worth noting that neither the DA*300mm nor the DA150-450mm have aperture rings so you wouldn't be able to control the aperture when on the LX.

Steve

The OP's K5 can't control the aperture of a PLM lens, it will be wide open all the time.

Yes if you're taking it on a hike, not if you're on a gentle wander round a nature reserve and definitely not if you're spending an hour or so in a hide .

Steve