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Forum: Pentax Forums Giveaways
09-01-2018, 10:00 PM
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Forum: General Talk
08-30-2018, 08:03 PM
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A priest and a businessman went out for a round of golf.
On the first hole, the businessman sliced the ball far into the rough. "%$*@ it, I missed" was his response. The priest rolled his eyes to heaven and remained quiet.
The businessman did no better at the subsequent holes, and as his frustration increased, so did the volume of his profanity. By the 17th hole the priest could restrain himself no longer, and he told the businessman that his language was offensive to the priest and to his God.
The poor businessman took one last, futile attempt to keep his ball in play on the last hole. As he was about to give one last blasphemous cry of despair, the storm clouds rapidly gathered, the sky darkened and thunder began rolling in the heavens.
Suddenly, a gap parted in the clouds and a lightning bolt arced down to earth, striking the priest on the top of his tonsured head and killing him stone dead.
An enormous booming "%$*@ it, I missed" was heard for hundreds of miles.
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Forum: Sold Items
08-30-2018, 07:31 PM
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I have the Vivitar Series 1 version of this lens by Kiron, and it's one of my very favorite lenses. Incredibly sharp, flat field and great colors. Best of luck selling it.
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Forum: General Talk
08-29-2018, 11:10 PM
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Reminds me of when a particularly annoying 19 year old next door told me that my kids were too noisy while playing in my yard, since he was working on a major project for his very important new job. When he asked what I did for work, I told him that I pushed drugs for a living, and when things didn't work out the way I planned, people got cut up in all kinds of interesting ways.
I retired from surgery over 5 years ago, but "retired" to a full-time post in IT :)
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Forum: Pentax KP
08-29-2018, 10:44 PM
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I tried it out for the first time seriously last weekend as a focus aid with a new long lens (the 160-450) that I was trying out for autofocus accuracy vs manual, while I was shooting some birds down at the reserve. It worked very well - and it showed me that I have a little more tweaking to do with the autofocus point on the KP for this lens.
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Forum: Pentax Forums Giveaways
08-29-2018, 10:17 PM
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There certainly is. Of course, when it was film cameras I always lusted after the 120 and 126 large formats, but I could never afford them back then. There is always something bigger...
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Forum: Pentax Forums Giveaways
08-29-2018, 09:26 PM
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Keep it and use it. I haven't had a Pentax full frame since my film cameras were retired to mostly decorative use, and a succession of digital bodies took over.
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Forum: Do-It-Yourself
08-01-2018, 07:51 PM
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Yes, that's what I believe too. I'm more used to getting a relatively heavy gantry or spindle mounting moving from stationary, getting it into place and stopping or reversing without a lot of jerking and vibration. That causes overshoot and puts a lot of stress on the tool (and the machine) due to the inertia/momentum. Gentle acceleration to a plateau speed and gentle deceleration back down is a lot smoother and less stress on everything (just like your car example). The camera is a lot lighter, and distances here are small in numbers of steps, but it's still a big jump from zero to full speed in one microstep, and if the motor's load is too heavy, it may miss steps and move too little, as well as stressing the motor. The other nice thing about AccelStepper is that it holds the home position in a variable, and that makes it easy to move repeatedly to absolute numbers of micro-steps from home and to finally return to home.
Make sure you get the current limit right for the motor you're using. It's usually quoted on the specs for the motor. Steppers are pretty voltage insensitive over a fairly wide range, but limiting the current matters, especially if micro-stepping. Those TB6560s make setting the current really easy, compared with twiddling minute pots on some of the small controllers while trying to measure voltages on test points you can barely see (I'm also in the trifocal years).
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Forum: Do-It-Yourself
07-31-2018, 09:10 PM
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That's a nice little project. You might want to look into micro-stepping a little further, as the movement is smoother and more controllable - especially if you use stepper control software that ramps up and down to accelerate/decelerate gently, like the Arduino AccelStepper library does. I don't know which stepper driver you're using, but most are compatible, so there is no extra cost. Your movement per micro-step is then pitch / steps per rev x micro-stepping rate = (4mm/200) x 1/16, or 1.25 microns per step for a 1/16 micro-stepping rate.
What are you using for stacking software? I've never tried macro-stacking, but I have done quite a bit of playing with these motors and Arduino or STM32 for other projects (CNC and 3D printing, mostly, and a "barn-door" for playing astro-photos).
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Forum: Sold Items
07-25-2018, 09:01 PM
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Forum: Sold Items
07-24-2018, 07:15 AM
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Forum: Sold Items
07-15-2018, 03:59 PM
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Payment sent.
These were also sold under the Lester Dine name for dental macro-photography back when some dentists used film cameras. Lester Dine also re-packaged the excellent Kiron 105 mm f2.8 macro (also sold as Vivitar Series 1) which these attach to via the filter ring screw-thread. I have the Vivitar Series 1 version for Pentax. These two pictures were taken with that lens and one of these flashes.
Kevin
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Forum: Sold Items
07-15-2018, 02:49 PM
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I have several of these under another manufacturer's name. PM sent to buy this one.
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Forum: Site Suggestions and Help
03-27-2010, 04:38 PM
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I haven't been posting for a few months due to a host of other commitments, but I have logged on periodically as a reader and still donate. Somehow this time my auto-logon did not work either and until I tried to see who else hated these popups did not realize that I was on as a guest!
A general e-mail message to the members (like the e-mails I get for other new features) to inform them these only occur if not logged on might help avoid a lot of ruffled feathers - we don't look at the homepage welcome message for guests.
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Forum: Weekly Photo Challenges
08-25-2009, 10:53 PM
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Thanks, photolady for looking into the bird ID. I looked them up afterwards (we only have the White-faced ibis here on the Western side) to see more once I saw your post.
Very nice pictures all.
I love that first landscape, Jeff.
Here are a few more from my back yard from today. Goldfinches attacking the thistle seed sock:
I've sat for ages trying to catch the darned humming birds. Predictably, when set up in MF to shoot the finches, this one appears - no time for accurate focusing, no flash attached - then he's off again :)
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Forum: Sold Items
08-25-2009, 09:08 PM
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Item was held for the buyer at his request - payment now received and dispatch pending.
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Forum: Weekly Photo Challenges
08-23-2009, 08:49 PM
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Thanks for hosting again, Dave.
It seems to be a week for birds so far!
Dave, your blue jays up there are prettier than our version (Western scrub jay) that are down below (frightening off the hummers I was still trying to catch). Nice hip cat(fish)!
Tpeace (Tom) - you succeeded with the hummers!
Scott - you've found a nice blue heron there!
Maxwell1295 - beautiful shot of a beautiful couple!
Photolady - not sure which birds you have there!
xs400 - like #1 particularly!
One of the three Western scrub jays who "own" my back yard and cuss at me when I walk out there:)
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Forum: Weekly Photo Challenges
08-09-2009, 10:56 AM
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Thanks for hosting, Rense. Nice pictures with the Tak, too. That food looks good!
Andras - nice to see you back. Nice cold wine there, too.
Dave - those are interesting pelicans, didn't know they were up that far!
Eccs19 - nice timing :p
I've been wandering round the local creek for a couple of years since I last saw a green heron without seeing them, and suddenly last time there were two!
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Forum: Weekly Photo Challenges
08-08-2009, 10:30 PM
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Light Horseman - I like that 1st long exposure particularly.
Frank and Dave - both good full moon pictures!
Jan - that library looks like a very interesting piece of architecture, allowing natural light to pass right through to the area beneath.
Rense - I only hope that is a trick of juxtaposition; that bird looks way too healthy!
xjjohnno - nice first pics with the Bigma. You have such gorgeous wild birds to aim it at, too.
Steve - that looks like an interesting fort, even if a reproduction.
Here are just a few from early sunrise, with orange glow lighting everything, and soon after. All with the Sigma 150-500 HSM.
Acorn Woodpecker
Acorn woodpecker adult (below) and juvenile (above)
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Forum: Sold Items
08-08-2009, 05:25 PM
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Your pictures are beautiful!
I have the same lens and it is probably the last lens I would ever sell unless starving and homeless :).
If you are a nature/bird photographer this lens is hard to beat, and it works wonderfully with the Tamron 1.4x Pz-AF or the Kenko 1.5x converters with minimal loss in IQ, as you show so well here.
Best of luck with the sale!
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Forum: Sold Items
08-06-2009, 03:53 PM
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PentaxForums.com Marketplace Listing
Item for Sale
Sigma 150-500mm F5-6.3 APO DG HSM lens
Asking Price
$850 (firm)
Item Description
I have my "Big Sigma" for sale. It is a very nice lens to use, but I really do not use it enough to keep. It is a very good wildlife lens. Its weight and balance make it surprisingly stable handheld, using the K20d's SR.
Overall, it is in excellent condition with all paperwork and the original lens hood, box, soft case, and a UV filter is included. Lenses are clean, obviously free from fungus,etc. It has a slight wear spot on the tripod ring (shown in the photograph) but otherwise the finish is very clean. It does not need any correction to autofocus on my K20D.
This model has the HSM contacts and HSM works well with the K20D, unlike the Bigma.
A few photographs from this lens:
at 370mm (handheld)
at 500mm (car window clamp)
at 500 mm (handheld)
Are you the original owner of the item being sold?
No
Are you selling or trading this item?
Selling
Item Condition
Used
Excellent
Item Location
Chico, CA
Shipping Charge
Inclusive (USA mainland only).
Shipping Services
USPS Priority
Shipping Destinations
United States
Accepted Payment Types
PayPal Check/Money Order
Additional Details
B&H are currently selling new at $999.
With the size and value of this item, I am not shipping outside the USA.
Personal checks need to clear through the bank before dispatch.
Please send me a private message if interested in the item!
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Forum: Weekly Photo Challenges
08-04-2009, 11:29 PM
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That looks like a fun festival, Dave. The Ukrainian costumes in particular are very photogenic!
Here are a few bird pictures (most of my birding is in winter, but can't resist a few if I can catch them).
Male California Quail
And his mate
And a Lesser Goldfinch eating the Star thistles
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Forum: Weekly Photo Challenges
08-04-2009, 03:24 PM
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Thanks for hosting this week, AOski.
Still very hot here, so a few macros from the back yard. (All with the Kiron/Vivitar 105/2.5 on K20D)
Crop from #1
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Forum: Weekly Photo Challenges
08-04-2009, 12:38 PM
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Young deer, soon after sunrise.
K20D/DA*300 at 1/500 f4.5
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