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Forum: General Talk
07-13-2023, 05:24 AM
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Nice!
Most surplus junk filters can be easily de-glassed (by unscrewing or popping-out the retaining ring) The empty filter ring can then be screwed on to a lens to provide just a bit of protection by reducing the chance of fingerprints, wear-and-tear on the screw threads of the lens, and the chance of denting the lip of the lens.
A tall stack of de-glassed filters could also be used like extension tubes with a reverse-lens macro setup.
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Forum: General Talk
05-31-2023, 07:19 AM
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For my birthday, I got a Tamron XR Di AF 28-300mm F3.5-6.3 Lens Reviews - Tamron Lenses - Pentax Lens Review Database as an all-in-one superzoom for travel and other scenarios where there's no time to swap lenses (or carry a big bag of primes). Preliminary testing found no decentering, very little distortion, and better than expected optical performance for a zoom with a 10.7:1 range. Wide open, this lens might not be as sharp as a good prime, but it seems decently sharp when stopped down.
Kudos to Premier Camera of Japan who advertised the condition of the lens as "Good" and warned it was a "used item" when, in fact, the lens (and box) seem absolutely like new. The lens and included Tamron lens cap, back cap, and hood have no dust, scuffs, or scratches. The only hint that the lens was not fresh from Tamron was the "Precision Camera" tape on the inner bubble wrap bag and the lack of any Tamron paperwork inside the box. Premier Camera also did an excellent job packing the lens.
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Forum: General Talk
05-07-2023, 06:43 AM
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Saturday, I went to a local garage sale that advertised cameras. On the table were 5 high-end lenses for Nikon (f/1.4 primes and f/2.8 zooms) and 3 nice Meike Cine lenses but nothing Pentax. :(
I asked if he had anything for Pentax but he said he used to but then sold it all a long time ago. (He was now in the process of selling all his Nikon stuff to move to Canon RF.) But, he said, he did still have a Pentax wired remote trigger. He quickly dug it out of the bottom of a box of assorted tidbits, handed it to me, and said it as free! :)
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Forum: General Talk
01-18-2023, 04:46 PM
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Samyang 24mm F3.5 ED AS UMC Tilt/Shift Lens - Pentax Lens Review Database (See PF's in-depth review at Rokinon Tilt-Shift 24mm F3.5 Review - Introduction | PentaxForums.com Reviews for an in-depth review)
I’ve been wanting a tilt/shift lens for a long time. A few years ago, Amazon had them in stock, I bought one, and recieved the wrong lens (some sort of Samyang prime for Sony). Other had the same problem because Amazon had mis-labelled a batch of the wrong lenses as a Samyang 24 T/S Amazon barcode. So back it went. Darn!
Recently, Amazon showed a small stock these lenses on their “Amazon UK Imports” so I tried again. Using the free shipping option (3 weeks), the lens arrived in two weeks using a 3rd party (ASENDIA) and the US Postal Service, Although the box was a little damaged after it’s long jounrey through the bowels of the low-cost global shipping system the lens was fine thanks to Samyang’s excellent job of packaging (stiff corrogated cardboard box, well designed foam endcaps, and plenty buffer space for dents and scratches).
Quicky tests showed good sharpness and negligible decentering (only noticeable on astrophotography which is not the point of a slow f/3.5 tilt lens)
I’ll write more thoughts as I study this lens and learn more about how to use the Scheimpflug principle to best advantage.
As of this posting, Amazon still has 5 of these left: amazon.com : Samyang 24 mm F3.5 Tilt Shift Lens for Pentax |
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Forum: General Talk
12-11-2022, 04:12 PM
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The night sky is a very convenient and pretty stringent coma test chart -- bright infinitesimal points of light on a black ground. If that isn't available, a city skyline at night with shots taken so the horizon is on the edge of the frame can also reveal coma and aberrations.
Good luck (and we look forward to your results!)
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Forum: General Talk
11-15-2022, 11:07 AM
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Indeed! I'd love to see an SMU in IR! :)
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Forum: General Talk
11-15-2022, 06:28 AM
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If the filters are any good, you'll see nothing through them! ;)
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Forum: General Talk
06-12-2022, 02:55 PM
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After more than two years of no new (old) lenses entering my life, I got a Tamron 28/2.5 (Tamron Adaptall-2 28mm f/2.5 (02B) - Pentax Lens Review Database) at an "everything must go" garage sale for $10 this morning.
Now I'm wondering: does the "Great 28" compete with the "Nifty 50" in the LBA department?
This is my fifth 28mm prime (M 28/2.8, K 28/3.5 Shift, Vivitar 28/2.5, M42 Vivitar Series 1 28/1.9) not to mention my motley assortment of seven zooms that include 28 in their range.
I'll definitely be testing this lens to see how it does. If it turns out to be "Meh" then at least I'll have a Pentax Adaptall 2 mount I can use for some other Tamron lenses.
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Forum: General Talk
08-23-2021, 02:08 PM
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Thanks for the link. I'd wondered if Kindles were hermetically sealed like some devices Apple. It's good to know this is possible. Based on what I've seen so far, I think my Kindle's battery might be like yours -- it charges OK but then dips 5-10% quickly.
The only remaining "latest acquisition" issue is whether to "acquire" the firmware updates (the device seems to have its fresh-from-the-factory install of version 5.0.1) but the Kindle Touch can run anything up to 5.3.7(Kindle E-Reader Software Updates). My personal experience with upgrades is that 1/3 of them help, 1/3 make useless changes (e.g., rounded icons!), and 1/3 hurt (e.g., slower performance and less room for files). Amazon does not seem to provide any release notes for the ancient firmware versions compatible with the Kindle Touch -- at least Pentax is better than Amazon in explaining what each firmware upgrade brings!
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Forum: General Talk
08-23-2021, 06:34 AM
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Indeed! Originally they wanted $30 on Friday, then it was marked down to $20 on Saturday. The seller was a neighborhood/seen-in-the-local -park acquaintance who offered me a bit more of "going to a good home" discount. Physically, the device is in mint condition but I'll need to use it more to find out if years of sitting in the box have shortened the life of the battery.
I also prefer black-print-on-paper to glowing-pixels-on-glass both at night and in sunlight. Fortunately, this Kindle's E-ink display is much more like diffuse-reflective paper than shiny-luminous screen. The tablet form factor is also easier to carry and hold than something like the 800-page brick that is Dicken's Bleak House.
Now, if only I had time to read all the books I've downloaded!
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Forum: General Talk
08-22-2021, 06:54 AM
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Got a used(never-used) Kindle Touch for $15 at a garage sale. It's an older (4th gen) Kindle with a very pleasant e-Ink display.
I've started downloading various classics off Free eBooks | Project Gutenberg such as Charles Dickens, Wilkie Collins, HG Wells, Jules Verne, Edgar Rice Burroughs. At about 1 MB/book and 2,999 MB of free space, it should have room for more books than I could hope to read in a lifetime.
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Forum: General Talk
01-27-2021, 08:29 AM
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What lenses did you two try on it?
You'll find that the focus limits of a non-infinity M42-PK adapter are a very strong function of focal length. Wider angle lenses might refuse to focus beyond a few inches. In contrast, telephoto lenses will work out to tens or even hundreds of meters. Portrait focal length lenses (say 85 to 135mm) will probably work at portrait distances. Zooms vary but generally work better than you'd expect because so many of them focus beyond infinity to begin with that they still get close to infinity even with the adapter.
As with many things in photography, some combinations of equipment work better than others. That means that any given bit of equipment will suck under some conditions but work well under others.
Try your adapters with some other lenses... you might be pleasantly surprised.
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Forum: General Talk
11-25-2020, 03:05 PM
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Condolences!
At least we can assume they are "digital" and "mirrorless." ;)
Is there any chance you can epoxy a quick-release base or a ballhead to the left cast to use with the tripod mount for your camera? :-)
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Forum: General Talk
11-05-2020, 08:15 AM
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Cool computer!
One hobbyist segment that will be extremely pleased by the Pi 4 are those looking to muck about with machine learning, AI, and more intensive data collection. The Pi 4 is a much more powerful machine than any of it's predecessors (Benchmarking the Raspberry Pi 4. Last year?s release of the Raspberry Pi? | by Gareth Halfacree | Medium). For signal processing and machine learning, the new Pi has 4X the Linpack computing performance and 10X the data bandwidth on the USB bus. It also has 3X the speed on the GPIO side which should enable projects needing more responsive control of things like robotics.
That said, you are probably right that Raspberry Pi is looking to expand sales to non-hobbyists looking for a cheap desktop.
Have fun!
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Forum: General Talk
10-25-2020, 02:30 PM
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Indeed! I've been burned before in ye olden days when an 80 GB hard disk was HUGE and making a back-up either meant buying a second (expensive) hard disk or taking the time to feed 26 DVD-RAM cartridges into my computer to do a full back-up. Needless to say, I neither spent the money on the former nor took the time to do the later often enough and was bit in the back-side!
Once-bitten, twice-shy, I now do have back-ups (two Apple Time Capsules with hourly incremental back-ups + four other hard disks at home or in a safe deposit box at the bank) but I did not like how I was storing my main copy. Nor did I have any good fail-over system. If my main computer goes kablooie or I've fled to an evacuation center, I couldn't access my files easily. With this SSD, a bootable OS install, and the rsync copy of my user account, I'll be able boot from the SSD and be back in business in minutes. (At least that's the theory!)
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Forum: General Talk
10-25-2020, 09:59 AM
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Latest acquisition: a better way to store all my images and data.
We've had some serious forest fires recently reaching with 6 and 9 miles of our house and a somewhat more distant fire that grew 20 miles in less than one day. Although our house has a fire hydrant in the front yard, I doubt it would do much good in the face of a fire that was burning through 70 football fields per minute! Although I do have offsite backups of all my data and cloud storage of a lot of working files, I wanted something local, fast, and very portable if we had to flee at a moments notice. On top of that, I've been unhappy with storing all my images on an external hard-disk which either spins continuously or must be dismounted.
So, enter the Oyen Digital U32 Shadow 4TB SSD. It's a bus-powered USB-3.2 device that comes with cables for USB-C to USB-C and USB-A ports. It's extremely portable (3"x5"x1/2" and no power brick) and very fast (seems to run 10X to 25X the speed of the firewire external hard disk). Currently, I've got copies of all our files on the drive. Once the fire danger is passed (6-12 inches of snow in the next couple of days should significantly reduce the danger), I plan to take the time to install MacOSX on the drive, use rsync to maintain a current copy of my files, and be able to have a bootable device that can get me up and running in the event of a computer failure.
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Forum: General Talk
06-23-2020, 03:13 PM
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LOL!
It's not surprising, though. If us Pentaxians don't want to buy a "normal" Canikony camera, why would be buy a "normal" lens?
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Forum: General Talk
06-07-2020, 03:17 PM
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Holy Guacamole! That's a whole mess of interesting fiddly tidbits. The possibilities look endless.
Perhaps you can rig the motion sensor and/or ultrasonic range sensor to detect things in front of a camera and then use the servo or stepper motor to mash the shutter button. (Extra credit if you make the ultrasonic range sensor more accurate than Pentax AF ;) )
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Forum: General Talk
05-20-2020, 10:10 AM
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It will probably be either: Opticomycetes ebayensis, Vitromycetes ruinosis, or Photomycetes hazinii. ;)
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Forum: General Talk
05-19-2020, 02:26 PM
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Happy Birthday and Congrats on the non-traditional Birthday Pi!
I've got my ZX80 sitting in the basement along with a motley assortment of other old computing kit.
The Raspberry Pi looks frighteningly amazing and the ecosystem of add-on apps and hardware tidbits make it look like it could absorb 5000% of one's free time!
Enjoy!
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Forum: General Talk
05-16-2020, 02:11 PM
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Awesome score!
I love to disassemble old cameras like these just to see what made them work. The optics and mechanisms are amazing to study and understand -- very clever designers! Sometimes the tidbits can be repurposed for frankenlenses. The diffusers inside the LCD display panels are also interesting light modifiers for flashes.
And those little carrying cases are extremely useful. Threaded through waist-pack belt or camera strap, they are excellent for carrying spare batteries, small primes, or snack bars.
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Forum: General Talk
05-14-2020, 06:31 AM
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No doubt! But I'm sure there's some tricky bits -- even when the gas is shut-off, there's residual pressure in the lines. At one point one of the workmen dressed up in a full kevlar suit, helmet, oxygen tank, mask etc. to work in the hole -- probably to remove the old tap and open up the main line to install the new tap.
The welder did not wear any protective gear beyond what an ordinary welder uses. After he was done, it was a little unnerving to see the gas main still smoking from the residual heat of welding on the new tap.
It was quite a production: at least six trucks, two trailers, a backhoe, horizontal directional drill, and a dozen men. Although it took then some time to get started in the morning, they were done and gone by early afternoon.
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Forum: General Talk
05-13-2020, 02:05 PM
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My most recent acquisition involved GAS, but not Gear Acquisition Syndrome.
We had a natural gas leak out under the street in front of our house and in the line to our house so today a bunch of men and their very big toys installed a new one. There was never any danger from the leak (just an odor) although I was shocked that the flag man controlling traffic on our street was smoking and then further shocked to learn that putting in a new line entailed welding a pipe to the main gas line.
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Forum: General Talk
03-31-2020, 06:17 PM
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Died in a snack attack! A vicious case of assault & vinegar! ;)
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Forum: General Talk
03-31-2020, 06:14 PM
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Perhaps you wearing a mask will increase the chance that people actually practice good distancing. :-)
Or you can look at it this way. There's sporadic random gunfire going off in your neighborhood and town. The gun men (and women and children) are all the people who have COVID-19 (including asymptomatic carriers) who are out and about. Anyone who leaves their house has a chance -- maybe a low chance but not zero -- of getting hit by their COVID snot bullets. So, do you go out?
Sure, some fresh air and fresh food would be nice, but is it worth getting shot?
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