Sigma 150-600mm f5-6.3 Contemporary DG OS HSM Lens - Canon Fit


Link Posted 19/07/2018 - 23:53
McGregNi wrote:
You've got a K3 ..... Do you know how much of a crop you can do with that sensor and not have any significant loss at the output sizes you use? ..... Do you really need 600mm...?

As you know, the time comes along when you just dream of a new lens. Birds in flight and sports now seem to be the way for me. Very relaxing.
Pentax K3 Pentax SMC-FA 50mm 1.4
Pentax Kr Pentax SMC D FA 100mm F2.8 Macro
SMC DAL 18-55mm Pentax SMC DA 18-270mm F3.5-6.3
SMC DAL 55-300mm Pentax DA 15mm HD F4ED AL
SMC Pentax-M 1:2.8 28mm


Link Posted 20/07/2018 - 12:34
i would say for consistant results with those subjects you need to change system completely or as others have said buy a cheaper older model body (be it Canon, Nikon or whatever) to go with the lens.
K3 II and the odd lens or 2

Last Edited by redbusa99 on 20/07/2018 - 12:35


Link Posted 20/07/2018 - 17:06
I have seen it written before that we should firstly choose the lenses we need, or want .... And then buy a camera that they go onto!

That seems to be the way this thread has gone. It's probably an approach more suited to professionals I feel an enthusiast I find it hard to break away from the "DSLR System" approach, where we choose a system (brand) based on a number of general qualities, and then find the lenses that serve us best within that system.

That's why I still wonder whether a 600mm lens is truly a necessity for the OP, given the cropping potential of the K3 sensor. The Sigma 50-500 is fairly easy to find for Pentax isn't it? The cost of the longer zoom has to include the other camera body as well, plus the inconvenience and extra effort to gain experience with a new DSLR system.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver


Link Posted 20/07/2018 - 17:24
I suppose we don't always apply logic to our purchases - sometimes just fancying something is enough.

If it were all about just capturing great images, then 450, 500, 600 isn't going to make much difference. Sometimes lenses won't ever be long enough. One thing is for sure - the longer they get, the heavier and larger they get and the more difficult they become to master.
Best regards, John


Link Posted 20/07/2018 - 23:38
My take on it is, like most areas of photography, you get out of it what you put in. The web is full of fantastic shots from various lenses, but you don't always appreciate the effort they've required from the photographer.

A 600mm on APS-C is a 900mm equivalent - this is a huge lens, even framing birds in flight will be difficult. Shutter speeds would need to be very high and focussing will always be difficult. Either way it won't fit a Pentax body.
PPG Flickr


Link Posted 21/07/2018 - 06:44
I do own and use a 600mm (645 on a genuine Pentax k to 645 adapter) that is adapted on my K3. I also use it for wildlife. So the points that I would like to make are that, so long as the subject does not move that much, you can use it. You need to use a decent tripod, as one hand is for focusing. The first couple of shots, is to check exposure and focusing. It is harder as you are using manual everything. If it moves, forget it. It is only going to be a world of frustration. 600mm at times, is just not long enough. It really depends what you are going to shoot. I have used it on deer in the New Forest, and it is fine as are the sparrows at the bird feeder twenty paces away.

A EOS lens to K mount body adapter, not sure if one even exists. Plus how limited in function it would be will limit you.

AF is going to be a key with moving wildlife. We went whale watching, I took my K3 with a Tamron 70-200 f2.8 attached, and there was more than one time occasion when I wanted to lob the camera in the sea because of it's AF. If it is the camera, or the screw drive lens, I really don't know. I don't want to invest money in Pentax's newer lens offerings to find out at the moment.

To over come this problem of limited long lens selection, I ended up buying a used Canon 7D for wildlife, and I am more than happy. You have a bigger selection of long lens, and and the AF is better than my newer K3. But I still prefer the output of my K3's images.

The way I work now is that if it moves, it is Canon. If it is static, it is Pentax. You don't have change systems.

Hope this helps.

Armed with a K3, some M, A, FA, DA, and star lens. With an eye open for "just one more lens".

My PPG link


Link Posted 21/07/2018 - 08:45
It's a lot cheaper to buy an aviary and some pet birds

Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff



Link Posted 21/07/2018 - 10:02
A Typhoon jet is a bit out of my price bracket though.
No equipment list here but thanks for taking an interest. My Flickr


Link Posted 21/07/2018 - 10:15
Mike-P wrote:
A Typhoon jet is a bit out of my price bracket though.

Time to clear out some of those fancy lenses then 😂😂😂
I'm sure the missus would understand if you told her what you wanted to buy 😲😲😲
I know what i like, If not always why.


Link Posted 21/07/2018 - 15:45
DFA 150-450 plus 1.4 TC gives you 630mm

AKA Welshwizard/PWynneJ
Assorted Pentax/Nikon/Mamiya stuff


Link Posted 23/07/2018 - 14:15
michaelblue wrote:
I have a Sigma 150-500mm in Pentax fit for sale, if you're interested.

there is a simple way round it if you are good with soldering buy this lens and a 150/ 600 and swap mounts over then you will have the 150/600 in pk mount
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