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Forum: Pentax K-3 III 04-05-2021, 07:01 PM  
K-3 Mark III - Comparing SAFOX 13 to previous generations of SAFOX autofocus
Posted By bwDraco
Replies: 13
Views: 3,039
In the spirit of this nearly decade-old thread, here are some AF grid diagrams. The circles are selectable AF points; those that are filled are f/2.8 high-precision points. Small dots are assist AF points which cannot be selected. The two are not to scale; SAFOX 13 covers a wider area of the frame than SAFOX 12. Note that the two assist points left and right of each of the center three points in the center column are also f/2.8 high-precision points. Sorry if this is a bit messy; drawing is not my strong suit. Regardless, this should highlight how similar the new AF system is to the previous generation.



Draco
Forum: Pentax K-3 III 04-05-2021, 07:12 AM  
K-3 Mark III - Autofocus at f/8
Posted By bwDraco
Replies: 4
Views: 1,646
You've got more data to track moving subjects with.

The AF algorithms did see a significant update in SAFOX 12 (K-1), where an arbitrary combination of points can be indicated as in focus rather than no more than two. Assuming that this remains the case for the K-3 Mark III, the extra points will provide a lot more data, increasing the accuracy of predictive focusing.

Pentax engineers did note that they've essentially redone the AF algorithms in SAFOX 13. Among other things, the AF system retains a longer history of tracking data in memory, and can better cope with erratic motion and sudden changes in velocity. We can't say for sure until more users have had experience with the camera, but I would be very surprised if AF.C performance did not improve significantly.

As for AF at f/8, I don't think the size or number of AF points really matters here.

Draco
Forum: Pentax K-3 III 04-04-2021, 02:00 PM  
independant K3 III First impressions / Full Res Video and Sample Pics
Posted By bwDraco
Replies: 23
Views: 3,687
My main concern is how well this camera performs with sports and action. This is basically the primary use case for a high-end APS-C camera and I'm wondering how well the new AF system handles stuff like birds in flight.

Also, Pentax's buffer depth numbers are rather low and I'm not too sure how much the camera will benefit from a fast memory card. With a good UHS-II card (200+ MB/s write), what should I expect when shooting RAW+JPEG at 12 fps?

Draco
Forum: Pentax K-3 III 04-04-2021, 12:55 PM  
K-3 Mark III - Autofocus at f/8
Posted By bwDraco
Replies: 4
Views: 1,646
The manual says the points are disabled. This is the first time Pentax has done this and it's probably a consequence of the wider coverage of the AF array. This isn't unusual for these sorts of high-density AF systems, but given how Canon does it, I wouldn't be surprised if f/8 autofocus would be impacted in the same manner, possibly in a future firmware version.

Draco
Forum: Pentax K-3 III 04-04-2021, 10:59 AM  
K-3 Mark III - Autofocus at f/8
Posted By bwDraco
Replies: 4
Views: 1,646
The K-3 Mark III introduces a greatly-improved autofocus system, SAFOX 13, with a high-density grid and wider frame coverage. But with certain lenses, some or all of the outer points are disabled. Among the lenses affected is the DA 560mm f/5.6, with which only the center grid is available.

But what about autofocus at f/8, e.g. with the DA 1.4x teleconverter attached? Previous Pentax cameras did not disable or limit autofocus functionality in any way with lens/teleconverter combinations slower than f/6.3 (outside of the oddball 1.7x autofocus converter), so I'm wondering if there are limitations with or specific support for autofocus at f/8. Autofocus performance at slower than f/6.3 is, of course, not guaranteed on any Pentax camera thus far, but given that the list of lenses with limited autofocus functionality in the manual (page 117) is subject to change, will we see this with firmware updates (e.g. center point only)?

Draco
Forum: Pentax K-3 III 04-03-2021, 07:41 AM  
K-3 Mark III - Comparing SAFOX 13 to previous generations of SAFOX autofocus
Posted By bwDraco
Replies: 13
Views: 3,039
Thinking more about how Pentax has implemented the new AF system, and looking at this page... I get the impression that the basic design of the secondary image registration (SIR) optics has not changed dramatically, except for optimizations to expand the AF grid to cover more of the frame and improve overall performance. (Pentax engineers note that they did have to redesign the entire mirror box, including by using a larger AF sub-mirror.) The SIR optics are the beam splitters that project the light to the actual AF sensor and is what determines the layout of the AF points. It also still has a "chromatic aberration compensating lens", which is almost certainly the diffractive optical element introduced in SAFOX IXi+. (More information about SIR optics in this Photography Stack Exchange thread.)

The SIR beam-splitter lens is referred to as the "separator lens" in this diagram from the Pentax Japan web page for the original K-3, which also depicts the diffractive optical element:



What is likely to have seen a more significant change is the underlying AF sensor. The sensor behind the SIR optics is what actually detects the phase difference to determine how to adjust focus. Using a higher-resolution sensor would allow each point to be smaller and make focusing more precise. This, in turn, enables a denser AF grid with many more points than before. In conjunction with other improvements, this should significantly improve subject tracking performance. A new focus sensor would also explain improved low-light focusing performance, down to EV -4 with f/2.8 lenses.

The expanded frame coverage of the AF array does come at a cost: page 117 of the manual states that with certain lenses, some or all of the outer columns of AF points may not be usable. While this is not unusual for high-density, wide-area AF systems—on the Canon EOS-1D X Mark III, lenses are divided into as many as 10 groups for the purpose of determining AF functionality—this is the first time we've seen a limitation of this type on a Pentax camera. The lenses affected are primarily consumer-grade zooms and wide-angle optics.

Draco
Forum: Pentax K-3 III 04-03-2021, 06:26 AM  
K-3 Mark III - Comparing SAFOX 13 to previous generations of SAFOX autofocus
Posted By bwDraco
Replies: 13
Views: 3,039
I jumped ship to Olympus over a year ago, but still have all my Pentax glass. I'm really intrigued as to what the K-3 Mark III has to offer. All the specs look very promising to me and it might just be enough to get me to dust off the D FA* 70-200mm f/2.8 lens and invest in the Pentax K system again.

Draco
Forum: Pentax K-3 III 04-02-2021, 10:38 PM  
K-3 Mark III - Comparing SAFOX 13 to previous generations of SAFOX autofocus
Posted By bwDraco
Replies: 13
Views: 3,039
For over a decade, Pentax has only made iterative improvements on the SAFOX AF system. More recent updates added more rows and columns but did not change the layout of the AF array. A closer examination of the SAFOX 13 AF grid reveals both similarities and differences from previous generations of the SAFOX autofocus system.

SAFOX 13 continues to use fundamentally the same layout of rows and columns as that of SAFOX 12. Among the selectable points, the center area is still a 5x5 grid of cross-type points, flanked by two columns of linear points on each side. The number of selectable points in each of these side areas has, however, increased from 4 to 8. The total number of selectable AF points is now 41, up from 33 in SAFOX 12 (K-1 and K-1 Mark II) and 27 in SAFOX 11 (K-3 and K-3 II).

But more significantly, SAFOX 13 adds an additional 60 assist AF points, dramatically increasing AF point density and making each point much smaller. Looking at pages 60 and 61 of the manual, when selecting a particular point to use, you can choose whether or not to use the four adjacent assist AF points. Select mode uses these additional points, while Select (S) does not. It also means that the Spot mode is much more precise than before. The AF grid also covers a much wider portion of the frame. All of these improvements are likely to be the result of both improved optics and a higher-resolution AF sensor.

Despite the similarities to earlier generations of SAFOX, the smaller AF points and higher point density represent a very welcome change. It addresses a common complaint with earlier Pentax cameras that the AF points are too large for precise selection. Combined with the high-resolution metering sensor enabling AI subject recognition, new AF algorithms, and an overhauled drive system which gives the AF system more time to track movement, I can see a dramatic improvement in AF.C tracking performance in the K-3 Mark III.
















You Tube




Questions, thoughts, or comments?

Draco
Forum: Pentax K-3 III 04-02-2021, 09:59 PM  
Advantages of K-3 Mark III over the K-3 II
Posted By bwDraco
Replies: 75
Views: 5,616
Building on this, Canon's newer high-density AF systems come with a very long list of lenses and the groups they fall in. The EOS-1D X Mark III has as many as ten groups of lenses and lens/extender combinations. Hence, there's nothing unusual about losing some of the outer AF points with certain lenses.

Draco
Forum: Pentax News and Rumors 10-27-2020, 07:34 PM  
[New video Oct 27] New information about upcoming APS-C flagship model
Posted By bwDraco
Replies: 1,603
Views: 116,158
The autofocus system and continuous shooting capability are greatly improved and look very impressive, but I'm distinctly concerned about the buffer depth, which points to slower buffer clearing than I'd like to see.

Pentax claims 32 RAWs at 12 fps and 37 RAWs at 7 fps. This comes out to a buffer clearing rate of only about two RAWs per second. UHS-II can definitely do better than that. If we're assuming 35 MB RAWs and a card capable of 280-300 MB/s, it should be possible to write 5-7 RAWs to the card each second. Hopefully, Pentax will sort this out before release, and they have time to improve the firmware to speed up buffer clearing.

Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 03-09-2020, 05:42 PM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710















You Tube



Forum: Canon, Nikon, Sony, and Other Camera Brands 03-06-2020, 11:27 AM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
Olympus OM-D E-M1 Mark III with M.Zuiko 12-100mm f/4 PRO @ 57mm; 1/250s f/5.6 ISO 200. Out-of-camera JPEG. Click through to see the full-resolution image on Flickr.
Forum: Canon, Nikon, Sony, and Other Camera Brands 03-05-2020, 10:39 AM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
So... I ended up taking the plunge yesterday and got the E-M1 Mark III with the M.Zuiko 12-100mm, plus a 64 GB SanDisk Extreme PRO UHS-II card to put in slot 1. (The second SD card slot was populated with an older 64 GB UHS-I card; only slot 1 supports UHS-II speeds.)

First impressions are very, very positive: S-AF is extremely fast, decisive and accurate; a brief C-AF test on some seagulls in flight produced surprisingly high keeper rates; high-ISO performance is above expectations; and the image stabilization is almost supernatural: A 1/3s exposure at 100mm (200mm equiv. 135) came out perfectly sharp. My Panasonic flashgun (originally purchased for my FZ1000) also works as designed, which is expected because Olympus and Panasonic flashguns are pretty much identical to each other. The lens hood on the M.Zuiko 12-100mm positively latches with a button release so it can't accidentally come off. USB Power Delivery support is a huge boon, because it lets me charge (or operate) the camera in the field using the USD PD power banks I already have. And above all, it's amazing how compact and lightweight this setup is.

The only major complaint I have is the steep learning curve: Olympus OM-D cameras are notorious for their complexity and it'll take me a long time to make sense out of all the menus and controls.

In less than 24 hours of ownership, Olympus has managed to seriously impress me. Pentax needs to step up their game and deliver something competitive.

Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 03-02-2020, 12:00 PM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
To be honest, I do intend to shoot birds in flight, but that's not the only—or even the primary—goal of this setup. The thing is that Micro Four Thirds gives long reach with less weight and bulk than APS-C or full-frame systems. And as far as I can tell, the OM-D E-M1 line has autofocus that's more than capable of doing birds in flight.

This is meant more as a general-purpose setup. While wildlife photography is a focus, birds in flight is only part of this, and the overriding concern is reduced size and weight. Indeed, I'm well aware that a smaller sensor means compromises in image resolution and low-light performance, and nothing rules out my going into Sony Alpha or any other camera system (including continued use of the Pentax K system) for situations requiring maximum image quality while continuing to use Micro Four Thirds for everyday photography.

This is why I'm continuing to maintain my Pentax gear, at least until I know what they have in store later this year.


Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 02-29-2020, 01:43 PM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
So... I'll clarify that I'm moving towards nature and wildlife photography. As stated earlier, indoor sports photography is no longer a focus. Reduced size and weight, and high shooting performance, are key. From what I've read, the 20MP Four Thirds sensor is just about as good as the Pentax K-3 II's sensor despite the smaller size, though the pixel count is a bit lower.

Sony looks incredibly tempting to me. Exmor image sensors are the industry standard, and Sony's Real-Time Tracking AF technology is often considered to be the best available in any camera, reflex or mirrorless, but I'm not sure I want to buy into a full-frame system. Besides size and weight, Sony glass tends to be very expensive, more so than Canon and Nikon.

It's still a very hard call to make. Perhaps I'll end up maintaining two mirrorless systems (Micro Four Thirds and Sony Alpha) and selling my Pentax kit? I don't know. For the time being, I still feel M4/3 is the best solution for my needs.

Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 02-27-2020, 06:11 PM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
I've looked into the Nikon D500 myself but ultimately decided not to go in that direction because 1) it's still quite large and 2) the D500 is four years old.

It is true that the sensor and EVF used in the otherwise new E-M1 Mark III are not new and have been around for the last several years as well. However, after a trip to B&H to try it out (it was on display with the M.Zuiko 12-100mm f/4 PRO attached), I came away impressed at the performance and compactness of this setup, being not much larger than the Panasonic FZ1000 I've been using the last couple of years. The autofocus, while not flawless, is exceedingly fast in low light and tracks moving targets much better than expected. While I'm pretty sure the Nikon D500 will outperform the E-M1 Mark III in AF and low-light performance, the D500 + 2.8/70-200 combination is substantially heavier than the E-M1.3 + 2.8/40-150 setup.

To be honest, this isn't an easy call. I'm still strongly leaning towards the mirrorless solution but will be looking at other possibilities as well.

Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 02-26-2020, 04:39 PM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
Truth be told, it is a bit sad for me to take this first major step away from Pentax, but I still have hope that they'll come out with something awesome.

As for adapting lenses, I realize it isn't exactly optimal to adapt modern full-frame glass to M4/3, and I'll need a mount adapter with aperture control to use the D FA* 70-200mm, but I kinda want to be able to use what I already have. Of course, as others have suggested, I'll be looking into getting the M.Zuiko 40-150mm f/2.8 PRO in the future, and possibly even the upcoming M.Zuiko 150-400mm f/4.5 PRO. Indoor sports photography is no longer a focus of mine so sensor size and lens speed aren't as critical as they used to be.

If I'm selling gear, it'll probably be later rather than sooner. I'm not entirely ready to leave the Pentax ecosystem.

@rawr: As far as I can tell, the E-M1 Mark III uses the same sensor as the one in the E-M1X and E-M1 Mark II. Low-light performance and dynamic range are at worst unchanged and at best slightly improved due to the new TruePic IX processor.

Draco
Forum: Canon, Nikon, Sony, and Other Camera Brands 02-26-2020, 06:08 AM  
Going into Micro Four Thirds - I'm getting an Olympus OM-D E-M1 Mark III
Posted By bwDraco
Replies: 120
Views: 7,710
It has been six months since I've started a new full-time job, and after being out of the photography world for a while, I am writing with sadness that I will be buying into another camera system.

While the Pentax K-3 II and D FA* 70-200mm f/2.8 lens has been instrumental to my work in the last year of my tenure as a sports photographer for my college, I have had a number of issues with this and my Pentax gear generally, ranging from AF sub-mirror delamination on my Pentax K-3 II to the gear simply being too large and heavy for me to carry on a daily basis. Ricoh's lack of significant technological progress over the last few years has not helped. After some thoughts about my requirements, I've decided that Micro Four Thirds is the way to go, and I'll be getting an Olympus OM-D E-M1 Mark III, most likely in early April. It will be purchased in a kit with the M.Zuiko 12-100mm f/4 PRO lens.

For the time being, I am not selling any of my Pentax equipment, and may even get an adapter to reuse some of my existing Pentax glass (particularly the D FA* 70-200mm f/2.8). Indeed, I realize there are situations where there's ultimately no substitute for a traditional DSLR, and I have not ruled out getting Pentax's long-awaited APS-C flagship due to be released later this year. Also, Pentax has a line of ultra-compact primes that I have not fully explored...

Your thoughts on this?

Draco
Forum: Pentax Camera and Field Accessories 04-24-2019, 01:53 PM  
Monopods: Goodbye Oben CTM-2500, hello Gitzo GM2562T
Posted By bwDraco
Replies: 10
Views: 1,443
After a day at work, it's pretty clear that Gitzo's Carbon eXact tubes have vastly superior rigidity. The Oben monopod feels like a toy in comparison. Lesson learned: Not all carbon fiber is created equal.



Draco
Forum: Pentax Camera and Field Accessories 04-16-2019, 07:57 PM  
Monopods: Goodbye Oben CTM-2500, hello Gitzo GM2562T
Posted By bwDraco
Replies: 10
Views: 1,443
Forum: Pentax Camera and Field Accessories 04-16-2019, 12:19 PM  
Monopods: Goodbye Oben CTM-2500, hello Gitzo GM2562T
Posted By bwDraco
Replies: 10
Views: 1,443
...and it's here.

Unexpectedly, the monopod does flex a bit at the leg section locks (the floor sample at B&H had the same issue and it appears to be a design limitation of the Gitzo Traveler G-Lock), and the extra section makes it a bit more fiddly to set up, adjust, and take down. It also doesn't extend as long, though it's still is long enough with a few inches to spare.

Even so, it's still sturdy enough to handle my K-3 II and D FA* 2.8/70-200 on an Arca-Swiss ballhead. The carbon fiber itself is clearly vastly superior to the material in the Oben monopod: the lower section on the CTM-2500 would vibrate dramatically when fully extended, but there's absolutely nothing like that on the GM2562T.

The shorter closed length, at just over 14 inches, makes it much easier to carry. It's small enough to easily fit in my wheeled backpack even with the ballhead attached, without having to jump through hoops to get the zipper to close.

All told, it's a Gitzo and I would be very surprised if it doesn't hold up at least as long as my old monopod did.

Draco
Forum: Pentax Camera and Field Accessories 04-15-2019, 03:35 PM  
Monopods: Goodbye Oben CTM-2500, hello Gitzo GM2562T
Posted By bwDraco
Replies: 10
Views: 1,443
B&H didn't have it in stock in the store. They're shipping one out from their warehouse and it'll be here tomorrow.

Draco
Forum: Pentax Camera and Field Accessories 04-14-2019, 03:33 PM  
Monopods: Goodbye Oben CTM-2500, hello Gitzo GM2562T
Posted By bwDraco
Replies: 10
Views: 1,443
After more than five years of heavy use, my Oben CTM-2500 is finally being retired. The rubber foot has been worn down to the point where the retractable metal spike is exposed so it winds up scraping the ground. I generally don't need or want the spike so this is a problem. Also, the top leg lock is giving me trouble, with the rubber grip slipping around the plastic and the anti-rotation piece not preventing leg rotation reliably.

It is being replaced with a Gitzo GM2562T, and I'll be running to B&H tomorrow to get it.

Has anyone else here managed to wear out a monopod?

Draco
Forum: Pentax SLR Lens Discussion 01-31-2019, 07:55 PM  
Pentax FA 35mm f/2 flare resistance and performance on full frame?
Posted By bwDraco
Replies: 45
Views: 4,861
Well... on closer examination of product images, this is not merely a reskinning. In addition to the new grip on the focus ring, the material used for the lens casing appears to have changed.

The old FA 35mm lens used a smooth plastic which IME does not feel particularly durable (don't have the 35mm proper but the D FA 50mm macro uses the same, older, plastic material). The updated version has rough patterning consistent with the more rigid fiber-reinforced plastic used on newer Pentax lenses. This is very likely to be a plus for build quality.

Draco


On another look, the plastic mold lines on the new lens are exactly where they were on the old lens. Is this merely a difference in the paint they're using, or have they really changed the plastic material? In either case, the rigidity of the plastic in most newer lens designs is generally superior in my experience to the plastic used in older lenses (and in the DA 50mm f/1.8, a lens built to a price point).

Switching to a modern FRP would itself be a convincing justification for the increased price over the old lens.
Forum: Pentax SLR Lens Discussion 01-31-2019, 06:55 PM  
Pentax FA 35mm f/2 flare resistance and performance on full frame?
Posted By bwDraco
Replies: 45
Views: 4,861
Well, given the responses here, it's now abundantly clear that the performance of the old FA 35mm is more than good enough to justify the higher ($400) price tag, especially now that it has new coatings and refreshed aesthetics. As dated as the screwdrive AF and aperture ring may seem these days, it's pretty obvious that Ricoh saw no reason to change the mechanical design on the updated lens, and I have no objections to this decision. Noisy as it may be, screwdrive AF is generally fast and reliable on modern Pentax bodies (I have never heard of an in-body AF motor failure on a Pentax camera).

I will definitely be looking into getting this lens at some point in the coming months.

Draco
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