[RobG]

Does anyone have experience with both Pentax and Canon cameras using long lenses? I was attempting to photograph an aircraft this evening, and one sequence of images was entirely out of focus despite the viewfinder containing nothing but sky and F18. The DA*300 and K3 seemed incapable of continuous focus over a series of 32 images. Actually, it started in focus, lost focus at frame 7 and only regained focus at frame 26. When the lens is in focus, the quality is awesome, but I'm just getting heartily tired of it hunting and not being able to track something large and moving.

I have been on the verge of buying a DFA 150-450 but the lens is so expensive that I am seriously considering buying a Canon DSLR and a Canon lens instead - perhaps a 7D and a 100-400. I've been consistent with Pentax for a very long time now, and I've bought quite a lot of Pentax cameras and lenses, but for bird and aircraft photography, the DA*300 is driving me a little crazy. Maybe my copy is faulty - sometimes it suddenly goes from in focus to completely out of focus in a way that seems bizarre for hunting, and it takes so long to refocus that I lose a ridiculous amount of opportunities. Is there anyone who has used both Pentax and Canon gear and can speak to the comparison for situations like bird and aircraft photography?

I also lost a lot of photos this evening because the buffer filled and the camera stopped responding to the shutter release despite using high speed SD cards.

[D1N0]

Well Buy one then if you think it will make you happy.

[NZ_Ross]

Canon lens instead - perhaps a 7D and a 100-400

Can you borrow or hire this gear to try out yourself and get an answer?

[biz-engineer]

DA*300 is driving me a little crazy. Maybe my copy is faulty - sometimes it suddenly goes from in focus to completely out of focus in a way that seems bizarre for hunting,

Normally , for photograhying aircraft, Pentax AF works , especially the K3. Using K3 and DA300, I don't remember having had issues with aircraft not in focus. But I don't use AF auto, I use AF select with center point priority.

[Franc]

what were your settings?
with af-c, 9 point, tracking is not that difficult

[RobG]

what were your settings?
with af-c, 9 point, tracking is not that difficult

I tried both 9 point and 27 point and AFC. Given that the aircraft completely filled the viewfinder most of the time (shouldn't have used the teleconverter), the subject should have been obvious. Anyway, the point of my post was to hopefully find someone who has tried both Pentax and Canon lenses.

[Tas]

Does anyone have experience with both Pentax and Canon cameras using long lenses? I was attempting to photograph an aircraft this evening, and one sequence of images was entirely out of focus despite the viewfinder containing nothing but sky and F18. The DA*300 and K3 seemed incapable of continuous focus over a series of 32 images. Actually, it started in focus, lost focus at frame 7 and only regained focus at frame 26. When the lens is in focus, the quality is awesome, but I'm just getting heartily tired of it hunting and not being able to track something large and moving.

I have been on the verge of buying a DFA 150-450 but the lens is so expensive that I am seriously considering buying a Canon DSLR and a Canon lens instead - perhaps a 7D and a 100-400. I've been consistent with Pentax for a very long time now, and I've bought quite a lot of Pentax cameras and lenses, but for bird and aircraft photography, the DA*300 is driving me a little crazy. Maybe my copy is faulty - sometimes it suddenly goes from in focus to completely out of focus in a way that seems bizarre for hunting, and it takes so long to refocus that I lose a ridiculous amount of opportunities. Is there anyone who has used both Pentax and Canon gear and can speak to the comparison for situations like bird and aircraft photography?

I also lost a lot of photos this evening because the buffer filled and the camera stopped responding to the shutter release despite using high speed SD cards.

G'day Rob,

There's a lot of discussions about Pentax AF in the forums, it's likely that other systems will be better in this aspect, but having no experience with them I'm more curious to compare than throw away my investment in K mount. 'Apparently' both Canon and Nikon have faster/more accurate AF for the type of shooting you're discussing in this thread. I can't quantify what that means without trying it, so I hope to take a D500 and long lens to a motorcyle race to understand the difference between the best of another system and a K-1 /150-450 for myself. Maybe you should try this approach too?

If you and I do this then there's the next question: Now that we know how they compare, what do we do with this information? For me, I'm heavily invested in K mount and therefore not inclined to shift, but I do seek to understand what is out there and work on minimising any discrepancies the Pentax system 'may' have. If you are less invested in the K mount system your context is different and may decide to change systems to go with one that suits your requirements better.

So far as the DA*300 goes with AF hunting, yes it does. It can be a real pain. The 150-450 did it big time on my K5 last weekend too, but then that is a seven year old AF system. It was less of an issue on the K-1 BTW. The good thing with the DA*300 of course is manual override. I've captured motorcycle racing with the DA*300 on the K5 but needed to either switch to MF or be prepared to provide manual inputs to ensure focus tracking did what I required. This was the gear I owned so I worked with it.

There must be a reason that so many review sites report Pentax AF is not cutting edge , but I guess the question has to reside with what your preference is photographically and how fast/accuracte AF influences this. When you're talking more deliberate shooting the pendulum for image quality is not unreasonably argued towards Pentax. But; 3rd party support, flash integration and AF is definitely better supported elsewhere. Good luck with whatever you decide, but disregard the badge and find the kit that does what you want it to do.

Tas

[RobG]

Normally , for photograhying aircraft, Pentax AF works , especially the K3. Using K3 and DA300, I don't remember having had issues with aircraft not in focus. But I don't use AF auto, I use AF select with center point priority.

Don't get me wrong - I have lots of good photos of aircraft using the DA*300 and DA55-300. Are you using AFS or AFC? As I mentioned, it's possible that my DA*300 is actually faulty given that it often suddenly goes completely out of focus while trying to achieve a lock.

---------- Post added 18-03-17 at 10:40 PM ----------

Well Buy one then if you think it will make you happy.

I specifically posted in the "Non-Pentax Cameras" forum to avoid this sort of response. Spending over $3K on a FA 150-450 or more like $4K on a Canon DSLR and lens is not a small investment either way. I'm hoping to hear from others who have faced a similar choice in similar circumstances. I'm not whining about "Pentax is rubbish so I'm going to buy brand X".

[pathdoc]

Sounds like either your particular camera or your particular lens or both is having an issue. Upgrade, replace, repair... but don't jump yet until you have eliminated a technical issue specific to your gear.

[RobG]

Can you borrow or hire this gear to try out yourself and get an answer?

I don't know anyone I can borrow it from. A company in Melbourne was offering the DFA 150-450 for hire, and I was indeed considering that, because they also offered it as a try before you buy arrangement,, where the hire price comes off the purchase price. I have tried the DFA 150-450 briefly in Shinjuku inside the Ricoh display centre, but it's nothing like real world testing. Pentax used to hire lenses for use in Tokyo but not anymore. I will try talking to a photographer who posted photos using the Canon combination. He may be agreeable to trying it out...

---------- Post added 18-03-17 at 10:57 PM ----------

There's a lot of discussions about Pentax AF in the forums, it's likely that other systems will be better in this aspect, but having no experience with them I'm more curious to compare than throw away my investment in K mount. 'Apparently' both Canon and Nikon have faster/more accurate AF for the type of shooting you're discussing in this thread. I can't quantify what that means without trying it, so I hope to take a D500 and long lens to a motorcyle race to understand the difference between the best of another system and a K-1 /150-450 for myself. Maybe you should try this approach too?

If I can find a way of doing it, I agree it's worth a try.

If you and I do this then there's the next question: Now that we know how they compare, what do we do with this information? For me, I'm heavily invested in K mount and therefore not inclined to shift, but I do seek to understand what is out there and work on minimising any discrepancies the Pentax system 'may' have. If you are less invested in the K mount system your context is different and may decide to change systems to go with one that suits your requirements better.

Likewise, I'm generally happy with Pentax, certainly for any sort of photography other than birds and aircraft. I have a K3, a K5iis and a bunch of lenses. It's the cost of the DFA 150-450 which makes it worth considering a completely different camera/lens combination.

So far as the DA*300 goes with AF hunting, yes it does. It can be a real pain. The 150-450 did it big time on my K5 last weekend too, but then that is a seven year old AF system. It was less of an issue on the K-1 BTW. The good thing with the DA*300 of course is manual override. I've captured motorcycle racing with the DA*300 on the K5 but needed to either switch to MF or be prepared to provide manual inputs to ensure focus tracking did what I required. This was the gear I owned so I worked with it.

Quick shift is great, except that on my DA*300 it goes so far out of focus that manually bringing it back into focus takes far too long. There's no focus limiter (another plus on the DFA 150-450).

There must be a reason that so many review sites report Pentax AF is not cutting edge , but I guess the question has to reside with what your preference is photographically and how fast/accurate AF influences this. When you're talking more deliberate shooting the pendulum for image quality is not unreasonably argued towards Pentax. But; 3rd party support, flash integration and AF is definitely better supported elsewhere. Good luck with whatever you decide, but disregard the badge and find the kit that does what you want it to do.

Thanks for the well expressed and considered response. I'll have to try to find somewhere in Oz that hires Canon gear to see if I can try the Canon option and see how it behaves.

---------- Post added 18-03-17 at 11:05 PM ----------

Sounds like either your particular camera or your particular lens or both is having an issue. Upgrade, replace, repair... but don't jump yet until you have eliminated a technical issue specific to your gear.

The camera doesn't exhibit the same behaviour with any other lenses, and the DA*300 does the same thing on the K5iis and K3. I'll consider sending the lens for repair, although I don't know how successful that will be. Problems which don't happen 100% of the time are hard to resolve. Anyway, DA*300 aside, this post was more to do with a choice between the DFA 150-450 and buying a completely different DSLR/Lens combination.

[biz-engineer]

Are you using AFS or AFC?

I use AFC

[RobG]

This is the aircraft I was trying to photograph today. Part of the problem was that the amount of time it was in my field of view on each pass was small, and it was moving fast. The display was also very short. So any amount of hunting in the middle of that meant a lot of frustration, but the part which was the most disappointing was the series of 32 images where almost all were OOF.

FA-18F Super Hornet - PentaxForums.com

---------- Post added 18-03-17 at 11:10 PM ----------

I use AFC

Thanks! In airshows I have generally ended up using AFS because AFC just wasn't giving results as often as AFS and repeatedly hitting the shutter release.

[f22]

If you're using a FF lens on an APS-C body, the image circle is larger than the sensor, and cropping your viewfinder image. Also your effective length is 450 mm.

If your object is at infinity, like your plane is likely to be in the sky, then set to manual focus at infinity distance. Why mess with AF under that condition?

One last suggestion, go into the Lens recalibration function and see if your lens is back or front focusing. Typically the hunting from focused to unfocused happens if the lighting around the subject is pretty dark, which in your case (plane in the bright sky) is not.

Could be there is a problem with your copy of the lens, but try these other things first.

[Adam]

I'd recommend trying the new 55-300mm PLM. The resolution will be a bit worse than your DA*, but the AF is so fast that every shot will likely end up being in focus. The PLM motor provides almost instantaneous response. Might be way cheaper than going for a new system or picking up the 150-450mm (though the latter is really good from an IQ perspective, and also focuses faster than the DA*, but not as fast as the 55-300mm).

[biz-engineer]

Thanks! In airshows I have generally ended up using AFS because AFC just wasn't giving results as often as AFS and repeatedly hitting the shutter release.

Yes; that's the case when the camera AFC is set to FPS prio. You have to know also that AFC is not meant to lock on every shot, AFC works best on subject having constant speed on a trajectory where it is tracked.
Example for an aircraft: use AFC, beware of AFC hold setting prevents AF reactivity, keep the subject in the frame (panning if necessary) press AF until AF lock and then press the shutter further. Pressing the shutter all the way just take blurred shots and slows down the system preventing to take high quality shots when in focus. If you have a non defective DA300, and it hunts , it is because when you start AF, the lens defocus is such that the camera does not know when the subject is (when completely blurred, the camera does not know if it should move focus nearer to the camera or farther from the camera), that's why AF goes all the way near and back to far again (that's the problem with all long lenses as the DoF is much thinner vs shorter lens focal length). Use AFC, use 9 points, set AF hold Off, prefocus your DA300 at infinity, your system is ready. On the DA300, prefocus at infinity prevents hunting, especially because the lens does not have a limiter , and because the AF throw is shorter when starting from infinity as opposed to starting from nearest focus position.