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Forum: Pentax K-5 11-03-2011, 06:25 PM  
Thump sound on video
Posted By Entropy
Replies: 41
Views: 11,961
An update:

If I remultiplex the video using avidemux2 (set video and audio codecs to "copy" and leave output format as avi) - the resulting video encodes to H.264 perfectly in Handbrake with no audio problems.
Forum: Pentax Camera and Field Accessories 08-12-2011, 09:30 AM  
Car charger for K10d
Posted By Entropy
Replies: 16
Views: 3,336
Not all lighter sockets are switched. My Subaru's is, my old Chrysler LeBaron's wasn't.

Inverters can sometimes be a bit bulky compared to a dedicated DC charger. I got a set of third-party CTA batteries from Cameta Camera that included a charger that ran off of both AC and DC at a very good price.
Forum: Pentax K-5 08-12-2011, 09:27 AM  
Pentax and GPS
Posted By Entropy
Replies: 15
Views: 3,764
Geotagging is a nice reason for non-astro GPS use - but you can use standalone GPS receivers at $50-70 for this. Using such receivers gives you more data (like a complete tracklog) and more control (no accidental geotagging of photos at your house, leading the entire Internet to know exactly where you live).

Web Photo Geotags Can Reveal More Than You Wish - NYTimes.com - this is why automatic geotagging is BAD. It's too easy to screw up and leave it turned on when it shouldn't be.
Forum: Pentax News and Rumors 08-12-2011, 09:21 AM  
Pentax Accessories Price Increase
Posted By Entropy
Replies: 10
Views: 3,896
Definitive proof that Pentax is stupid.

Their response to low accessory sales is to RAISE prices?

Perhaps instead they should be looking into availability. People won't buy accessories they can't find... Half of the accessories listed are nearly impossible to find, and those that are findable are priced 2-3 times that of equivalent third-party accessories.
Forum: Pentax SLR Lens Discussion 06-29-2011, 07:55 AM  
Mirror Lens at DX
Posted By Entropy
Replies: 12
Views: 2,742
DX's price is more expensive than the Bower/Phoenix 500/6.3 lenses from B&H - and it's the same lens almost surely.
Forum: Pentax Camera and Field Accessories 06-29-2011, 07:52 AM  
Pentax and Tablet Computers
Posted By Entropy
Replies: 30
Views: 6,589
Problem is that pk-tether only supports the K10/20. So even if I got a tablet with USB host at best I'd be able to get it to work with the 20 from the terminal. ;)

(I am awful at GUI stuff...)

If you want a tablet with ports you may want to wait for the Toshiba Thrive - it's supposedly got LOTS of ports.
Forum: Pentax Camera and Field Accessories 06-27-2011, 07:50 AM  
Pentax and Tablet Computers
Posted By Entropy
Replies: 30
Views: 6,589
Wrong. There's nothing preventing you from compiling commandline ARM ELF binaries and running them on Android, other than the fact that apparently everything must be statically linked - which results in the binaries being huge. :(

As an example, see Shark for Root, which includes a commandline tcpdump binary and a Java UI to call the binary - https://market.android.com/details?id=lv.n3o.shark&feature=search_result

See also the various people who have compiled bash for Android. Which reminds me, I need to install bash on my Infuse.

I'm fairly certain it's possible to have a non-root commandline app - Shark needs root because tcpdump needs root for promisc mode.

Probably a tethering app would need root for USB bus access. Also not sure if anyone has gotten libusb running on Android.

Graphical apps are a different story - there is no GTK, Qt, or X support in Android. (Actually I think someone may have hacked up an X server - not sure.)
Forum: Pentax Q 06-23-2011, 10:43 AM  
Pentax Q in the Flesh
Posted By Entropy
Replies: 1,308
Views: 178,432
What in the world is Pentax thinking?

Less zoom range in the zoom lens than the Canon G12, with the same aperture
Significantly smaller sensor than the G12
Only slightly smaller than the G12 (body-only), highly unlikely to be smaller with the zoom lens mounted, and the mounted lens will make it "unpocketable".
MSRP $300 more than the G12... And that's without the zoom lens.

It's very disappointing that Pentax wasted their R&D money on this, instead of focusing on filling in the gaps in their SLR lens lineup and K-5 bugfixing.
Forum: Pentax Camera and Field Accessories 06-22-2011, 12:51 PM  
Pentax and Tablet Computers
Posted By Entropy
Replies: 30
Views: 6,589
As I understand it - Iconia A500 has USB host functionality right in the tablet.

The Eee Transformer only has it with the dock.

Many others don't have it at all.

As to tethering - if anything can control the Pentax via tethering, it would be the A500. PK Tether won't do it since it's Windows only. pkremote does run in Linux and could probably be compiled for ARM and run on the A500, however it has no Android user interface (would only work via terminal emulator or ADB) and doesn't appear to have been updated to support anything newer than the K20D.
Forum: Pentax SLR Lens Discussion 06-20-2011, 08:37 AM  
Is there such a thing as a decent superzoom (for Pentax)?
Posted By Entropy
Replies: 22
Views: 3,642
Since the Tamron/Pentax 18-250 are discontinued - the Sigma 18-250 is also an excellent lens.

It is FAR better than any Sigma superzoom I've ever worked with in the past.
Forum: Pentax Camera and Field Accessories 06-17-2011, 06:59 AM  
Spare Battery for K-5
Posted By Entropy
Replies: 18
Views: 3,100
I've always had good results with batteries and chargers bought from Cameta Camera. The ones for my K10/K20 were CTA branded, the new ones for my K-5 are Power2000 branded.

They're all still going strong.

In terms of potential damage or explosion - Obviously ultracheap batts can be dangerous, but ones bought from reputable domestic dealers seem fine. Also, unlike cell phones and laptops, we don't charge our batteries in-device, and that's the most likely time for an explosion. (It can happen on discharge though...) Also, our batteries are less "flat" than cell or laptop batteries, so less chance of a "flexing" battery causing a short.
Forum: Pentax K-5 06-14-2011, 07:54 AM  
Pentax and GPS
Posted By Entropy
Replies: 15
Views: 3,764
If it's in the grip, the antenna element will almost always be covered by your hands or facing downwards. This will degrade accuracy significantly. Plus I don't want to pay $50-100 extra for GPS in my grip, for the same reasons as not wanting to pay for it in the camera. Anything less than $50 and it's going to be an inferior chipset to anything I can buy standalone.

Also, having a GPS receiver always running is going to eat battery. If it's not always running, it will suffer degraded accuracy.

I don't like camera-top attachments either - similar reasons. It makes the camera bulkier, it results in the GPS not performing as well.

My iBlue is nice and small, and it Velcros perfectly to the top of my backpack. (It even came with Velcro!)
Forum: Pentax News and Rumors 06-13-2011, 10:51 AM  
GPS Pentax DSLR's
Posted By Entropy
Replies: 85
Views: 15,607
No, it isn't a fact. It is 100% wrong. https://gps.afspc.af.mil/gpsoc/PerformanceReports.aspx - Note that there isn't any significant north/south asymmetry.

GPS wasn't designed for North American civilian use - it has over time become so heavily used that it's operators are under a mandate to also support that role, but it was originally designed to improve the accuracy of weapons delivery (conventional and nuclear). Air Force bombers don't operate solely in the Northern hemisphere. Navy SLBMs don't either.

The only performance improvement Northern Hemisphere users may see over the South is that no one in the Southern hemisphere has started a system that is the equivalent of WAAS. Really, you're not seeing anything worse than I already do. (My hiking GPS is a Garmin Oregon, which has an STMicro Cartesio chipset - they STILL can't get WAAS working reliably...)
Forum: Pentax K-5 06-13-2011, 10:35 AM  
Pentax and GPS
Posted By Entropy
Replies: 15
Views: 3,764
Because that would add $50-100 to the cost of the camera.

Mobile phones can do it cheaply because it's OK for them to band-aid around a cheap horrible-performing correlator chipset using SUPL and ephemeride preloads.

Try using a mobile phone GPS in a no-service area (no SUPL) and no ephemeride preloads - enjoy your 10 minute+ lock times.

(I am reasonably familiar with the capabilities of some mobile phone GPS units, as at one point I tried to add SUPL and ephemeride preload support to the GPS driver for xdandroid, an Android port for phones originally intended to run Windows Mobile.)

There's also the fact that it ties the upgrade cycle of your camera and GPS together.

GPS L2C goes live? Ooops, gotta buy a new camera too!
Awesome new sensor in the latest body? Gotta pay for the GPS again.

Let's not forget that if the GPS is built into the camera, the antenna will only be optimally oriented in portrait or landscape orientation - not both, while with a standalone logger you can have it ALWAYS pointing upwards.

The only case where integrating a GPS directly with the camera makes sense is for the new astrophotography features of Pentax's new offering, or for the epically lazy who can't even be bothered to spend 30 seconds per photo album loading a tracklog.
Forum: Pentax Camera and Field Accessories 06-13-2011, 07:27 AM  
Hiking Monopod
Posted By Entropy
Replies: 15
Views: 7,344
How essential shock absorption is to a hiking pole is a matter of personal preference - It's more about comfort than durability.

However even poles without shock absorbers (I can lock my Leki to disable the shocks, for example) often have some amount of flex to absorb some shocks. The Sherlock might have similar flex.

The Trekpod is, of course, designed with photo first and hiking second, so may be less flexy than some of the hiking-first poles.

Also, while the flexing of the Sierra is awful at 250mm+, it may be fine for use for wider-angle shots.
Forum: Pentax Camera and Field Accessories 06-13-2011, 07:13 AM  
Third Party GPS units
Posted By Entropy
Replies: 18
Views: 4,851
Any GPS datalogger that can provide logs in a standard format (NMEA or GPX) can work with any camera with a reasonably accurate clock that records "time taken" EXIF data (which includes every Pentax digital camera in existence to my knowledge.)

Camera clock accuracy requirements are dependent on how fast you're moving when geotagging - 2-3 minutes off is fine for hiking, not good at 60 mph. A few seconds off is bad if you're taking pictures from an aircraft. :)

I use an iBlue 747A+ and love it. There are slightly newer iBlue models out now that use the same MTKv2 chipset. I also sometimes just use my Garmin Oregon 300.

The basic workflow is:
Record a GPS track with the logger

Take pictures with the camera

When you get home, download the images from the camera to your PC, and also pull the log from the logger. (Special software is required for the iBlue and other MTKv2 loggers, I use the free and open source BT747 tool - GPS Data Logger Software - BT747 )

Use geotagging software to tag the photos using the log, based on the position the GPS was at at the time the camera says the photo was taken. Most photo management software has this built-in now. I use digiKam as I'm a Linux user, I believe Lightroom and iPhoto support it. There are also free geotagging tools - there's a popular Windows tool, I think it's called Geosetter. BT747 may also have built-in tagging now.
Forum: Pentax K-5 06-08-2011, 10:46 AM  
Image stabilisation - In camera and In lens
Posted By Entropy
Replies: 7
Views: 4,694
Do you mean 18-250?

Anecdotally, in-lens IS supposedly does better at longer focal lengths, and in-body at shorter.

At longer focal lengths, the stabilized viewfinder (and similarly, stabilized AF sensor view of the workd) is highly beneficial for in-lens IS.

On the other hand - in-lens IS can't correct for camera rotation around the lens axis, while in-body IS can.

As others have stated, you can choose one or the other at a given time but not both.

I have noticed one annoyance with in-lens IS when combined with the Pentax K-5's movie mode - Even when the OS switch is "off" the lens element moves when the OS system gets/loses power. End result is that when you touch the AF button (even in MF mode), the image shifts, and then it shifts back after the AF timeout.
Forum: Pentax K-5 06-08-2011, 10:43 AM  
What to do about static sound in videos?
Posted By Entropy
Replies: 32
Views: 5,752
A 1 Hz or so "popping" sound is pretty typical for some players. Handbrake is one example.

I'll try mkvmerge for remuxing to see if Handbrake likes those files.

As to hotshoe-mounted mics - this is what I did for a bit as I already had one for my Canon HF100. However, the camera does have two pretty severe limitations - 32 kHz sample rate and forced AGC.

I'm starting to figure out the workflow for doing it the way the "pros" do it - record audio with a separate device (Zoom H2) and splice/sync that audio into the video.

The nice thing about this approach is that once I get the workflow down pat, I can record surround sound with the H2. :)
Forum: Pentax K-5 06-07-2011, 01:29 PM  
DNG vs. PEF
Posted By Entropy
Replies: 57
Views: 21,936
It doesn't really matter - it's not like if you buy a new camera you'll ever use it to read the old files.

If you're referring to software that processes the images themselves - if dcraw supports it fully, the argument becomes irrelevant (since a fully open-source implementation means the file format will never become unreadable). The K-5 was the first time since I started shooting Pentax that there wasn't full support for the body I purchased at the time I purchased it. (Semi-early K-5 adopter + ufraw has been a little slow in dev cycle lately, however dcraw did support it at that point in time.) Only reason I'm still using DNG is inertia.
Forum: Pentax Camera and Field Accessories 06-07-2011, 01:20 PM  
Hiking Monopod
Posted By Entropy
Replies: 15
Views: 7,344
Unfortunately, the design goals for a good trekking pole and a good monopod are very different.

A good monopod is ROCK SOLID with no flex/vibration when locked up, and is designed to take a constant but fairly low load (the camera's weight - 10-20 pounds at absolute most) without much need to absorb shocks.

A good trekking pole is light weight and needs to absorb shocks via in-pole shock absorbers and a bit of give/flex of the pole material itself, and take a heavy load without collapse, such as a hiker pole-planting as they glide over rocks. I have put the majority of my body weight on my Leki Sierra without any hesitation, and I've subjected it to some pretty significant shocks. (It DOES have a shock absorber after all!). However - as a long-lens monopod, the flex and bounce of the Leki makes it worse than handholding. It might work well for long-shutter wide angle shots, but it's awful for telephoto work, I tried it once with a Tamron 70-300, and I think even once with my Bigma, and the lens just bounced up and down way too much as the pole flexed.

Edit: A cheap-ass $10 Targus monopod is significantly more stable than the Leki Sierra photo pole. However, as a trekking pole, the Sierra is awesome, and in that way alone it's a great photographic accessory in that it helps you and your camera get to where they need to be.
Forum: Pentax News and Rumors 06-06-2011, 08:34 AM  
GPS Pentax DSLR's
Posted By Entropy
Replies: 85
Views: 15,607
GPS stands for Global Positioning System. Key word:

GLOBAL.

The NAVSTAR (original name for GPS) system was designed with a requirement for complete global coverage - a system that only worked "at home" would be useless for the Air Force and Navy.

Global Positioning System - Wikipedia, the free encyclopedia

However, augmentation systems that broadcast GPS correction data (local ionospheric conditions being the primary localized error source, satellite clock error is another but that's not localized) are local in scope.

WAAS only covers North America, and the scope where WAAS actually provides useful corrections (e.g. where iono information is valid) is even more limited than the signal coverage.

However, WAAS is only the difference between having around 10 meter potential error, and 5 meter or so potential error.

Edit: The European equivalent of WAAS is EGNOS. There's a Japanese equivalent too I believe. I don't think any augmentation systems are in use in the southern hemisphere, except for the classic local DGPS approach which few modern receivers support.
Forum: Pentax K-5 06-03-2011, 09:47 AM  
DNG vs. PEF
Posted By Entropy
Replies: 57
Views: 21,936
NEF is Nikon's RAW format.

Not sure what advantages it has over DNG.
Forum: Pentax News and Rumors 06-03-2011, 09:45 AM  
GPS Pentax DSLR's
Posted By Entropy
Replies: 85
Views: 15,607
Not true. No GPS receiver knows which direction it is pointed in, if GPS is the sole sensor source. A GPS receiver can only know in which direction it is moving.

To know which direction you are pointed, a heading sensor is required. In most hiking-oriented GPS units, this is achieved using a magnetic sensor (electronic compass) - electronic compass units usually DO need to be calibrated. (Every one in a handheld hiking GPS I know of has.)

As to the usefulness of heading - it's usually possible with a topo map or aerial imagery to know which direction the camera is pointing in. If there are no distinguishing features in the terrain or aerial imagery, the scenery probably wasn't very interesting to begin with.

I can immediately tell in which direction the camera was pointing for the majority of my geotagged images - the few cases where I can't don't justify $150 extra and the reduction in portability.
Forum: Pentax K-5 06-02-2011, 11:36 AM  
DNG vs. PEF
Posted By Entropy
Replies: 57
Views: 21,936
With older Pentax cameras, PEF was the way to go, as DNG was uncompressed.

With the K-5 (and from the sounds of it, the K-7 too), DNGs are compressed, I switched to DNG on my K-5 because ufraw hadn't been updated yet, and at this point I may as well stick with it.
Forum: Pentax News and Rumors 06-02-2011, 11:24 AM  
GPS Pentax DSLR's
Posted By Entropy
Replies: 85
Views: 15,607
The astrophotography features look really useful.

Nothing else in there warrants the $150+ price premium over MTK2-based dataloggers (under $100) which, unlike this unit, have a chipset with proven performance. (This may have a chipset with proven performance, but the actual chipset used is undocumented.) 50 channels implies it might be a u-Blox 5 in which case it'll be decent, otherwise - who knows?

Recording camera heading is somewhat useful, but I wouldn't find it of enough use to warrant the price premium.

This unit is going to add a protrusion to your camera that will cause it to be prone to damage when in its bag, and it will also suffer accuracy degradation from improper antenna orientation during portrait oriented shots. A standalone logger can be velcroed to the top of a pack/bag so it's always in the optimal orientation.
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