Posts for: Doyle Thomas
Sep 6, 2020 21:19:01 #
twowindsbear wrote:
Speaking of hydrogen. . . can anyone tell me, FOR SURE, how hydrogen is produced commercially? The 2 methods I have in mind are 'cracking' methane (or other hydrocarbon molecules) into carbon & hydrogen, and electrolysis of water. Either of which would require a bit - quite a bit? - of energy. So, how can hydrogen as a fuel to replace gasoline be economically possible?
solar an geo-thermal
Sep 6, 2020 21:13:05 #
CO wrote:
I didn't know that the space between the elements in a lens were filled with Argon gas. Is that only the best lenses? What do cheaper kit lenses have?
nitrogen or air
Sep 4, 2020 16:40:26 #
I recently took a class on vacuum technology. One of the topics was leak detection using helium and the point was made that "everything leaks". He is a noble gas, while common in the universe, it is not common in the atmosphere which could interfere with the detection process. Also the element is the 2nd smallest and can make its way through a small hole.
That got me thinking about cameras and lenses. The best lenses use argon, also a noble gas and a large molecule, to fill the space between the elements. The question is how long can be expected before the gas can become contaminated with atmosphere?
We all know removable lens cameras will build up dust and obtain a film (no pun intended) on the sensor even if you never remove the lens.
That got me thinking about cameras and lenses. The best lenses use argon, also a noble gas and a large molecule, to fill the space between the elements. The question is how long can be expected before the gas can become contaminated with atmosphere?
We all know removable lens cameras will build up dust and obtain a film (no pun intended) on the sensor even if you never remove the lens.
Aug 12, 2020 13:22:56 #
its good
to appricate this resource and be a source as well
to appricate this resource and be a source as well
May 20, 2020 10:43:02 #
http://www.primaryfocusphoto.com/usage-terms/
feel free to use this
feel free to use this
May 8, 2020 12:30:18 #
Feb 19, 2020 16:24:00 #
http://www.primaryfocusphoto.com/chronological-histroy-of-photography/
Feb 7, 2020 21:46:02 #
ckescher wrote:
Thanks Doyle. I appreciate your words of caution. As to your second reply, I do agree. I have seen some photos of the Milky way with a large DOF which had been lit from the side and you could see a person standing there. I think,it may have been in Az. Do you have any suggestion on the type of lens?
the best lens is the one on the camera.
Feb 7, 2020 16:49:06 #
Feb 7, 2020 16:46:16 #
Feb 7, 2020 16:43:07 #
watch out if u do Old Faithful, ppl tend to jump in front when it erupts for Photos, especially Japan ppl.
Jan 10, 2020 07:23:41 #
i attended a lens baby class a few years ago, they are made here in Portland OR. we all got a loaner lens to play with. I did not see any effect that could not be done in PS but as they pointed out, 'your bending light not pixels". mostly a gimmic IMHO but fun.
Dec 31, 2019 21:29:28 #
for months now this pops up when i load Nix. they want me to buy an upgrade with very little added value.
Dec 30, 2019 13:23:16 #
Shore Acers State Park OR for big surf and crashing waves
Dec 6, 2019 23:07:13 #
canned air held upside down