[Blythman]

Having persevered for about 8 years shooting wildlife with Pentax cameras, I finally bought a D500 about 4 years ago. I use it exclusively for wildlife, and Pentax for everything else.

It would be so much easier reverting back to a single system, especially when I already have the Pentax DFA 70-200, DA 300, DFA 150-450 and DA 560

So, of those who have experience of both cameras ..... is the K-3 III a game changer? Does it get very close to the D500 in terms of autofocus? Or does it still trail behind?

[redpit]

My simple answer is yes, the K-3iii is a game changer and the most integrated DSLR Pentax has created so far. It is very close to the D500 in AF performance and beats it in other sectors. With this collection of lenses you have it is a pitty not taking advantage of the K-3iii. What Pentax camera are you shooting with now?

[Fogel70]

If you can rent a K3 III to try it out for yourself it would be best. It is not just about the speed of the camera, but also the lenses.
Some older Pentax lenses have quite slow AF, so it can vary a lot depending on what setup you want to use the most.

[Blythman]

My simple answer is yes, the K-3iii is a game changer and the most integrated DSLR Pentax has created so far. It is very close to the D500 in AF performance and beats it in other sectors. With this collection of lenses you have it is a pitty not taking advantage of the K-3iii. What Pentax camera are you shooting with now?

I've 2 Mk 1 K-1's and a K-3, though that is rarely used

---------- Post added 06-17-22 at 11:55 AM ----------

If you can rent a K3 III to try it out for yourself it would be best. It is not just about the speed of the camera, but also the lenses.
Some older Pentax lenses have quite slow AF, so it can vary a lot depending on what setup you want to use the most.

I might just do that

[ThorSanchez]

If you can rent a K3 III to try it out for yourself it would be best. It is not just about the speed of the camera, but also the lenses.
Some older Pentax lenses have quite slow AF, so it can vary a lot depending on what setup you want to use the most.

I concur that the Mark III is miles ahead of prior Pentax cameras in terms of autofocus performance and a number of other areas. It's a great camera, especially paired with the 55-300 PLM.


But I don't have any of the long lenses the OP talks about, so I'd probably rent a K-3 Mark III and test them out, compare to the D500, before going all-in.

[The Squirrel Mafia]

The D500 is still the king of autofocus & buffer size in all APS-C DSLR cameras. The K-3III has very good AF performance, though, & like already stated, in certain circumstances the K-3III can actually do better than the D500. It also has IBIS, something that the D500 lacks. It comes in handy for those low light tripod free static shots. The K-3III is definitely a lot better than any other APS-C DSLR from anyone. Here's the thing. You need fast focusing lenses like the DA 55-300mm PLM, DA* 16-50mm f/2.8 PLM & similar to really get the best AF performance out of the K-3III. Screw drives & older SDM & DC lenses can only go so fast.

The one lacking thing in the K-3III is the buffer size. If you're into bursting a long sequence, the D500 can go on forever, while the K-3III goes on for about 30 shots or so & then it slows down. I personally don't burst forever, but there are many D500 owners that do. Maybe Ricoh will give the K-3IV a larger buffer in about 8 years from now. Hahha!

But yeah! The K-3III is the king of autofocus in all Pentax bodies ever released so far. Maybe the K-1III will be better, but that's a whole other FF game there.

[Larrymc]

Having persevered for about 8 years shooting wildlife with Pentax cameras, I finally bought a D500 about 4 years ago. I use it exclusively for wildlife, and Pentax for everything else.

It would be so much easier reverting back to a single system, especially when I already have the Pentax DFA 70-200, DA 300, DFA 150-450 and DA 560

So, of those who have experience of both cameras ..... is the K-3 III a game changer? Does it get very close to the D500 in terms of autofocus? Or does it still trail behind?

Yes sell it! Rental will not do the Mk III justice as it will take several weeks for you to take in all the nuances of the system. The only way you will appreciate the Mk III is to shoot with it for a while. It is a very exceptional camera!

[Oldbayrunner]

My take is outside of being able to use your Pentax Lens you wouldn't gain much by switching, especially since you own two K1's. The D500 even though older technology in many ways is equal to or better than the capabilities of the K3 lll... I don't personally see the K3 lll strong points making up much difference to go spend the extra $$$. The main gain would be having all of your gear one system, for what that's worth.

[gatorguy]

I concur that the Mark III is miles ahead of prior Pentax cameras in terms of autofocus performance and a number of other areas. It's a great camera, especially paired with the 55-300 PLM.


But I don't have any of the long lenses the OP talks about, so I'd probably rent a K-3 Mark III and test them out, compare to the D500, before going all-in.

I have and use all the lenses the OP mentioned other than the 560, and each of them is very fast to focus, working wonderfully with the K3III. On the 150-450 specifically focus speed benefits from using the limiter, which I'm sure the OP is already aware of.

[c.a.m]

So, of those who have experience of both cameras ..... is the K-3 III a game changer? Does it get very close to the D500 in terms of autofocus? Or does it still trail behind?

I know you're looking for direct comparisons. Sorry, I've never used a D500, but I have enjoyed my K-3 Mark III for the past year.

I've followed online reviews of the K-3 Mark III fairly closely. The only 'review' that I know that compared AF between the two cameras was an early DPReview video:

You Tube

You Tube

.

Concerning AF performance, the reviewer noted that the D500 "consistently had a higher hit rate," but no statistics were given and the 'test' was somewhat random and not comprehensive. The K-3 Mark III received favourable comments, though.

Unfortunately, there are few credible comparisons of the two cameras, if any. Even the anecdotal accounts from users (who may have used both systems) tend to omit important information such as lens models, shooting conditions, subjects, etc. It's difficult to design and conduct meaningful tests to compare AF performance.

- Craig

[gatorguy]

I know you're looking for direct comparisons. Sorry, I've never used a D500, but I have enjoyed my K-3 Mark III for the past year.

I've followed online reviews of the K-3 Mark III fairly closely. The only 'review' that I know that compared AF between the two cameras was an early DPReview video: https://www.youtube.com/watch?v=UpDDp3QEF34.

Concerning AF performance, the reviewer noted that the D500 "consistently had a higher hit rate," but no statistics were given and the 'test' was somewhat random and not comprehensive. The K-3 Mark III received favourable comments, though.

Unfortunately, there are few credible comparisons of the two cameras, if any. Even the anecdotal accounts from users (who may have used both systems) tend to omit important information such as lens models, shooting conditions, subjects, etc. It's difficult to design and conduct meaningful tests to compare AF performance.

- Craig

I can say for a fact that firmware updates since that DPR review have improved AF performance even more. Higher resolution, greater dynamic range, faster bursts, better viewfinder, IBIS, and all in a far more compact body have put more separation between the Pentax K3III and discontinued D500.

Just do it. One system sharing lenses is far easier to manage.

[jumbleview]

D 500? Of course you can. But selling Pentax K3iii considered to be a treason and will be punished accordingly. Be aware.

[eric1965]

Having used the bigger brother (D4-D5) of the Nikon D500 focus acquisition is very fast with AF-S Nikkor glass, even some older AF-D glass. What Nikon F lenses are you using on the D500?
Pentax K3mk3 as the Nikon D500 have a very performant AF module and I am of the opinion the limiting factor is the AF speed of the lenses used on the respective body as further refinements of the camera firmware and user knowledge, experience.

Both cameras have a learning curve regarding the utilization of the AF system and for me it boils down regarding ergonomics, habits of the photographer, available lens selection and after sale service.
Nikon D500 is apparently out of production. Selling the D500 could be interesting as there is still demand for this body and once stocks are depleted. It is like the Pentax KP now that the camera is out of production people starts to appreciate the merits of this body, second hand prices are basically the last list prices of a new camera...
Initially they were a lot of complains regarding the K3mk3 when the camera was released and most issues have been ironed out by firmware updates and the user understanding how the AF works.
My experience regarding Nikon AF modules: Most of the digital Nikon bodies I had needed a supplemental calibration at the service centre as even the AF fine tune did not work as intended.
Nikon service centre in my country is horrendous. I had to ship my cameras to the UK or the Netherlands for proper calibration, servicing of my various Nikon bodies.
Regarding Ricoh/Pentax service: As I bought several new and used bodies, lenses most of them were fine. My used K3mk2 was out of focus calibration and I readjusted so far so good through the "service menu" and patience. Both of my DA SDM lenses (16-50, 50-135 f/2.8) were serviced recently in France for replacement of the SDM motor in less than 14 days.
Try to rent a K3mk3 or just purchase one and in the unlikely event you are not happy you can still return the camera after 14 days (online purchase European law). I suppose you have something similar in the US.

[ThorSanchez]

Most of the digital Nikon bodies I had needed a supplemental calibration at the service centre as even the AF fine tune did not work as intended.
Nikon service centre in my country is horrendous. I had to ship my cameras to the UK or the Netherlands for proper calibration, servicing of my various Nikon bodies.
Regarding Ricoh/Pentax service: As I bought several new and used bodies, lenses most of them were fine.

As much as I like my Pentax cameras, service in the US is certainly not one of Ricoh's strong suits. There is one official service center in the entire country, Precision Camera in Connecticut. No matter where you live in the US, California, Alaska, Florida, wherever... you have to ship your stuff to Connecticut for repair.

I do not know how this compares to other brands.

[Mikesul]

Sony and maybe Nikon use Precision. With Sony and maybe Nikon if you qualify as a pro and pay a fee you will get somewhat enhanced service.