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Forum: Pentax Camera and Field Accessories 11-07-2018, 04:54 PM  
Just bought into the Arca-Swiss QR system
Posted By bwDraco
Replies: 7
Views: 660
So... I've posted an image of the Mandarin Duck on my Instagram account.

It hasn't gone through my full post-processing routine; I had only processed the RAW on my phone quickly using Snapseed. Regardless, I almost cried when I saw it and had to work my way through a big crowd in order to even get in position and set up my tripod.

Draco
Forum: Pentax Camera and Field Accessories 11-03-2018, 07:28 AM  
Just bought into the Arca-Swiss QR system
Posted By bwDraco
Replies: 7
Views: 660
Surprise: I actually got a Manfrotto MT055CXPRO3 for my birthday coming up soon. I'm bringing it to Central Park today along with the Monoball Z1+ sp to see if I can capture that elusive Mandarin Duck that's been making the rounds on social media...

Draco
Forum: Pentax Camera and Field Accessories 10-23-2018, 04:17 PM  
Just bought into the Arca-Swiss QR system
Posted By bwDraco
Replies: 7
Views: 660
Arca-Swiss heads have a few different Quickset options, including a twist lock and a lever lock. The lever lock is not guaranteed to be compatible with anything other than Arca-Swiss's own plates because it's designed to open and close to specific widths, and plates with different widths will not fit correctly. The twist lock does not suffer from that problem because it's continuously variable, but it's also slower to operate.

I have the twist-lock version of the Monoball Z1+ sp and haven't had any issues with the third-party (SpiderPro) plate thus far. I also have a genuine Arca-Swiss 40mm universal-fit plate; though I haven't tried it, I have no reason to believe that there would be any issues.

Draco
Forum: Pentax Camera and Field Accessories 10-23-2018, 09:00 AM  
Just bought into the Arca-Swiss QR system
Posted By bwDraco
Replies: 7
Views: 660
After over a year of being on the fence, I've finally bought into the Arca-Swiss quick-release system. I've acquired an Arca-Swiss Monoball Z1+ sp and a couple of plates, including a SpiderPro lens collar plate for use on my D FA* 70-200mm lens. I'm using this on my Oben CTM-2500 monopod, but will eventually get a better monopod as well as a proper tripod, (edit: see post #6) not to mention more lenses. Alas, my budget is limited and I don't have that much money to acquire all that gear at once.

The free motion allowed by a ball head takes some time to get used to, but the advantage of the Arca-Swiss head is that doesn't tip over as easily under load because it uses a spheroid ball whose tension increases as you move it away from the center position, addressing a problem I've constantly had with the tilt head it replaced.

The hard part, however, is properly deciding what heads and plates to buy. The Arca-Swiss QR system is very confusing to a newcomer, and I talked with the B&H sales associate for a long time before buying, discussing how supposedly "Arca-compatible" plates and mounts can be incompatible with other manufacturer's due to proprietary extensions and modifications, such as pins or other protrusions in the head and/or plate and inconsistent plate widths.

One last thing: B&H only lists the Monoball Z1 sp but the new Z1+ sp has the same SKU, so don't be alarmed if you can't find the new Z1+ model on their website.

Any hints on using this or suggestions on future expansion? Your thoughts on the Arca-Swiss system and its compatibility issues?

Draco
Forum: Pentax K-3 08-16-2018, 04:15 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
It's been sent to Precision for repair. I've made it very clear on the letter inside the package that the AF sub-mirror is delaminating and must be replaced, not merely cleaned.

The camera is out of warranty. My first job of the next season is September 1, so I'm paying for an expedited repair. Furthermore, I've shipped it out via Priority Mail Express for guaranteed overnight delivery, something I don't usually do.

Draco
Forum: Pentax K-3 08-15-2018, 07:50 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
Late reply, but I have inspected the AF sub-mirror again and the spots have reappeared, exactly where they were before I tried to "clean" them". The camera has seen very little use over the last few months. At this point, I am absolutely convinced that this is delamination and not contamination.

Ricoh seriously needs to know about this.

Draco
Forum: Product Suggestions and Feedback 06-17-2018, 11:11 AM  
Mirror cling clang when play, or enter the menu from live view
Posted By bwDraco
Replies: 3
Views: 734
The problem is that it takes energy to keep the shutter open and the sensor active. (On the K-3 family, as far as I can tell, keeping the mirror up alone does not require extra energy.) As such, the camera simply closes the shutter and lowers the mirror when in the menus. This behavior is by design, but at least the K-3 would automatically resume live view when you exit the menu. (The K-5 did not and you had to press the live view button again to do the same.)

Draco
Forum: Pentax K-3 05-22-2018, 10:59 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
Bubbles could just be voids between the surface and substrate. I can't really tell the difference between contamination and delamination at this point.

Draco
Forum: Pentax K-3 05-22-2018, 07:35 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
Now this is interesting. I put a cotton swab on it and the spots disappear. However, merely putting pressure on the mirror is enough to remove the spot, and I see no indication of streaking when I gently wipe it.

Hence, this does not rule out delamination as pressure can cause sub-surface bubbles to disappear, but it does suggest it could just be oil or other contamination.

Autofocus consistency has improved dramatically since this operation. I'll be monitoring this closely to see if this issue reappears.

Draco
Forum: Pentax K-3 05-21-2018, 02:53 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
Possibly. As far as I can tell, Precision only performed a CLA on the camera and its AF system; the AF sub-mirror may not have deteriorated to that point or they may not have recognized the true nature of the problem. The inconsistency reappeared a few months after the service.

Draco
Forum: Pentax K-3 05-21-2018, 12:45 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
The sensor was last wet-cleaned more than a year ago, and I have never cleaned the mirror with anything other than a blower bulb.

Liquid ingress seems possible, but that wouldn't really explain the spots in the middle of the AF sub-mirror, and the main mirror shows no evidence of similar contamination or damage.

Draco

---------- Post added 05-21-18 at 04:19 PM ----------

On my K-5, it looks like this:



Most of the spots in this case are dust, but notice the same discoloration around the edges.

Draco
Forum: Pentax K-3 05-21-2018, 11:04 AM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
I think I did post photos. Are you able to access Imgur?

Draco
Forum: Pentax K-3 05-21-2018, 08:22 AM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
On my camera, some of the spots bleed into the edge, so I'm pretty sure it's delamination.

I suspect the OP of that post merely pushed out the bubbles during "cleaning".



Draco
Forum: Pentax K-3 05-20-2018, 11:03 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
Found this thread reporting the same issue: autofocus inaccuracy, green spots on the mirror? - PentaxForums.com

If anyone else has autofocus sub-mirror delamination, please tell us about it. We might have a serious design flaw on our hands.

Draco

---------- Post added 05-21-18 at 02:07 AM ----------

Another thread reporting this problem: pentax mirror spots - PentaxForums.com
Forum: Pentax K-3 05-20-2018, 09:26 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
I took a closer look at my old K-5 and I found similar delamination of the AF sub-mirror. This points to a design flaw that Ricoh may not be aware of and needs further investigation.

Everyone, try gently lifting up the reflex mirror on your camera(s) slightly and examine the small mirror beneath it for delamination. Be careful not to touch the surface of the mirror; touch only the lower edge and consider using gloves. We need to find out if there's a hitherto unnoticed design flaw in the mirror assembly and if so, tell Ricoh about it.

I just sent a Tweet to Ricoh Imaging US regarding AF sub-mirror delamination; hopefully, this will get more attention about this problem.

Draco
Forum: Pentax K-3 05-20-2018, 08:41 PM  
AF sub-mirror delamination causing inconsistent focusing – anyone else affected?
Posted By bwDraco
Replies: 45
Views: 3,769
My Pentax K-3 II has been suffering from occasional focusing problems where the camera may lock focus far off target at times even in good light on a high-contrast subject. The error is typically front-focus but can sometimes be back-focus, and cannot be addressed by AF fine adjustment because of its inconsistent nature. The behavior also appears to be somewhat dependent on color temperature. All of my lenses are affected.

I tried cleaning the AF sensor with a blower bulb and while it appears to have improved, it did not completely address the problem. Should I try again, or send in the camera?

Has anyone else sent in their cameras to Precision for this issue, and did they address it effectively? If I'm to send mine in, should I send in the lenses as well? The camera is out of warranty, but that's not an issue for me.

Draco


It turns out the problem is delamination of the AF sub-mirror. How this is even possible is beyond me, but it looks like this will have to be sent to Precision.




Anyone else experienced this issue? Here's the note I'd send with the camera:


Draco
Forum: Visitors' Center 04-23-2018, 08:16 PM  
Pentax K-3 II with weather proof-sealed body
Posted By bwDraco
Replies: 19
Views: 1,834
The K-3 II is technically discontinued but remains available from major dealers, including B&H and Adorama. While it is highly resistant to water and dust ingress, it is not completely impervious to the elements. I've personally dealt with a malfunction on my K-3 II (with no lasting damage) after continuous exposure to heavy rain for more than an hour during a soccer assignment more than two years ago.

Draco
Forum: Pentax Full Frame 02-22-2018, 02:59 AM  
K-1 Mark II: Accelerator unit frees up processing power for autofocus?
Posted By bwDraco
Replies: 31
Views: 3,767
@MJKoski, this isn't medium format we're talking about. Although it's best for landscape and studio photography, the K-1 Mark II is meant to be a multipurpose camera that can handle a bit of action as well.

Draco

---------- Post added 02-22-18 at 05:08 AM ----------



Per Ricoh Imaging, the accelerator unit performs image processing before the data gets to the main PRIME IV engine:

Draco
Forum: Pentax Full Frame 02-22-2018, 01:26 AM  
K-1 Mark II: Accelerator unit frees up processing power for autofocus?
Posted By bwDraco
Replies: 31
Views: 3,767
The idea I had in mind was the image processing requires a certain amount of processor resources. For predictable performance, specific amounts of processing power are reserved for this purpose. Because this is now done by a separate accelerator unit, fewer resources can be reserved for image processing and noise reduction, which means that the AF system can use more of the processor than before. Is this technically possible?

Draco
Forum: Pentax Full Frame 02-21-2018, 11:02 PM  
K-1 Mark II: Accelerator unit frees up processing power for autofocus?
Posted By bwDraco
Replies: 31
Views: 3,767
An interesting idea came up while I was thinking about the changes in the K-1 Mark II.

The press release states that the noise reduction is handled by the accelerator unit first seen in the K-70. This enables a significant improvement in noise handling under extreme low-light conditions. It also states that the K-1 Mark II has updated AF algorithms.

However, most of the hardware is exactly the same. The continuous shooting speed is still only 4.4 fps in full-frame mode, which AFAICT is limited by the image sensor's readout speed and not the processor. But why can't the old K-1 get the same AF improvements?

It dawned upon me that by offloading image processing, including noise reduction, to the accelerator unit, more processing power is available for the autofocus system. This enables the use of more complex predictive tracking algorithms, which would result in enhanced AF performance.

Any official word on this?

Draco
Forum: Pentax News and Rumors 02-04-2018, 02:18 PM  
K3ii replacement
Posted By bwDraco
Replies: 2,451
Views: 159,148
Here's what I'd like to see in a K-3 II successor:
  • Faster, higher-density AF array. As a sports photographer, I often have trouble getting precise focus on distant subjects, and as subjects move closer to the camera, I need to be able to accurately track them. The K-3 II often has trouble tracking fast-moving subjects in poorly-lit indoor arenas, even with a fast lens like the D FA* 70-200mm. A faster and denser AF array that can keep up in low light would make a huge difference.

  • Faster continuous shooting. 8.3 fps sometimes just isn't enough, and it slows down dramatically when using continuous AF. Having more images to choose from means I have a better chance of getting at least one keeper from within an image sequence.

  • Faster memory card slots. I do RAW+JPEG even with sports photography, and I need the buffer to clear quickly after each sequence in order to review them. The K-3 II tops out at about 40 MB/s writing to memory cards, limited by the SDR50 data rate, yet the generic media reader I have in front of me can do SDR104. While the K-1 has SDR104 slots, there's still room for improvement. Upgrading the slots to UHS-II (or even the upcoming UHS-III) would help dramatically.

  • Hybrid viewfinder system. I've thrown this idea around before: a transparent high-resolution color OLED display could be used in place of a transparent LCD (like the one used in the K-1) to provide a color viewfinder overlay and serve as an eye-level EVF in Live View. This would create new possibilities for the viewfinder, including focus peaking, dynamic grid lines, and more. Although this would add complexity, it should be technically feasible and would be a massive selling point.

Draco
Forum: Pentax SLR Lens Discussion 12-19-2017, 05:06 PM  
New gear: Pentax 16-85mm, flash diffuser, and circular polarizer
Posted By bwDraco
Replies: 4
Views: 754
The AF issues on the 18-135mm are actually due to loose lens elements: if I tilt the lens up or down, the focus will shift, and it may not focus to infinity at certain focal lengths after being tilted down. The AF motor itself is perfectly fine.

Draco
Forum: Pentax SLR Lens Discussion 12-18-2017, 06:29 PM  
New gear: Pentax 16-85mm, flash diffuser, and circular polarizer
Posted By bwDraco
Replies: 4
Views: 754
So... it's been a while since I last posted here, but I got some new gear today at B&H.

First and foremost is the Pentax DA 16-85mm lens (and the obligatory B+W clear filter). I purchased this lens to replace my venerable (and failing) DA 18-135mm, which is showing some really bad decentering and has unreliable AF. Unfortunately, there are some issues with AF consistency in low light (which I suspect is a camera body problem) and it took a -8 adjustment to get accurate focusing in good light (tested at both ends of the zoom range). I almost wanted to return the lens, but to be honest, a slow zoom in low light isn't always going to focus accurately. Otherwise, the image quality is head and shoulders above that of the old DA 18-135mm, with far more consistent corner-to-corner sharpness across the zoom range, and the 16mm wide angle is a boon. There's a bit of chromatic aberration at the 16mm end, but it's not severe by any means and is easily corrected for in post.

Second is a flash diffuser, the Gary Fong Lightsphere Collapsible with Speed Mount. I sometimes need to take group photos in my line of work, but direct flash looks really bad and bounce is usually not an option. The difference with the diffuser is striking from the very first image I took with it. Attachment onto my Metz 58 AF-2 flashgun is fast and easy, and it stays very secure. Flash metering remains accurate on my K-3 II, with no major adjustments needed.

Third is a 72mm B+W Käsemann circular polarizer—the new HTC version, in the slim XS-Pro mount. I haven't used a circular polarizer before, but have read about them several times and decided that it was about time to get one. I have not had a chance to try it just yet.

I'd like to see your thoughts, and any tips with the new gear are appreciated.

Draco


Edit: I just realized that the hood on my 18-135mm is cracked. This thing has definitely taken a beating, so if there was a time for me to get the 16-85mm, it would be now.
Forum: Repairs and Warranty Service 11-28-2017, 04:30 PM  
Help! K1 hot shoe came off (warning: k1 gore)
Posted By bwDraco
Replies: 55
Views: 3,358
As far as I can tell, the hot shoe is attached to metal on the K-3 II, so this is probably a design weakness of the K-1. I'm a bit surprised that the hot shoe could tear off like this.

Draco
Forum: Pentax DSLR Discussion 10-15-2017, 07:38 AM  
Sticky: About those WR body weather seals...User responsibility and best practice
Posted By bwDraco
Replies: 49
Views: 12,551
🤣🤣🤣🤣🤣

Jokes aside, I did wind up with something resembling demonic possession a couple of years back when I covered a soccer game in heavy rain. Back then, I was using the DA 18-135mm, which is far from ideal for soccer, but that was because I had no other suitable lenses on hand. The camera's SR system wound up going haywire, causing the sensor to shake continuously. At one point, the camera refused to turn on, but I let it air out after the game and all was good.

I haven't had any water-related issues since.

Draco
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