Everyone is entitled to his own opinion, but not his own facts. Founded by Mark Kleiman (1951-2019)
Inaugural picture
Got a new 70-300mm lens today for my Sony a6000 camera. I just pointed it at the moon and snapped on manual: 1/500 sec, ISO640, f16….
Maybe I should have gotten an even more pricey lens…
Author: Harold Pollack
Harold Pollack is Helen Ross Professor of Social Service Administration at the University of Chicago. He has served on three expert committees of the National Academies of Science. His recent research appears in such journals as Addiction, Journal of the American Medical Association, and American Journal of Public Health. He writes regularly on HIV prevention, crime and drug policy, health reform, and disability policy for American Prospect, tnr.com, and other news outlets. His essay, "Lessons from an Emergency Room Nightmare" was selected for the collection The Best American Medical Writing, 2009. He recently participated, with zero critical acclaim, in the University of Chicago's annual Latke-Hamentaschen debate.
View all posts by Harold Pollack
11 thoughts on “Inaugural picture”
No need to use f/16 when you are focussing at infinity. Even your largest aperture would still give you enormous DOF even though you would be using a long telephoto. f/16 on your camera is not an ideal aperture – you are getting significant diffraction there, so the image will not be as sharp. Sharpest aperture will be about f/5 – f/6 – ish, which will also boost your shutter speed a lot for sharper image. 🙂
When in doubt, bracket!
Better yet, here is an app that will tell you what your DOF is for your camera, lens focal length, aperture, and focus distance 🙂 : http://www.dofmaster.com/dofjs.html
Yes.
You could also use the wider aperture to lower your ISO and maybe reduce noise. Three stops – f/5.6 – would let you shoot at 1/1000 and ISO 160.
And as aajax says, bracket. It would take a few seconds to try some other exposures.
Good advice. 🙂
Exposure looks pretty good in photo, above. Not sure how much of viewfinder is taken up by moon at 300mm on a A6000, but if one used spot metering on the moon itself, I'm thinking that exposure would be pretty darned close at zero exposure compensation. I've never done astrophotography, but I would guess that without a tracking tripod, the moon would move quite a bit every second, so that very fast shutter speeds would be of great benefit?
I don't know. A very rough, and possibly wildly inaccurate calculation suggests it moves about three feet in 1/1000 of a second. I doubt that's going to get much blur. Maybe the camera steadiness will help.
OK. Let's see: Moon orbits Earth at ~ 2200 mph. Meanwhile, Earth is rotating at ~ 1000 mph at equator. I have no clue whatsoever how these two orbital rotations relate to one another as vectors. So, yup – about 4.9 feet per 1/1000 second worst case, so at 239,000 miles… I think you are right, and I was wrong. 🙂
Very cool!
Thanks everyone! Great advice.
The crowds in this photo are even more sparse than the inaugural pictures posted by the NPS. Did you doctor it to further deny Trump the glory that is rightfully his?
Back when my family had a summer place far from light pollution, down near a shore on a peninsula that was very sparsely populated in the off-season, I kept a nice telescope, and I was very familiar with the night skies, read the Celestial Events column at the end of Natural History each month, etc. There were four guaranteed crowd pleasers, over a May or October weekend: 1) the four Gallilean moons of Jupiter, 2) the rings of Saturn, 3) showing the star in the bend of the Big Dipper's handle to be a binary, and perhaps the most oooohs and ahhs of all, 4) a full moon, up nice and tight, with all that glorious topography.
No need to use f/16 when you are focussing at infinity. Even your largest aperture would still give you enormous DOF even though you would be using a long telephoto. f/16 on your camera is not an ideal aperture – you are getting significant diffraction there, so the image will not be as sharp. Sharpest aperture will be about f/5 – f/6 – ish, which will also boost your shutter speed a lot for sharper image. 🙂
When in doubt, bracket!
Better yet, here is an app that will tell you what your DOF is for your camera, lens focal length, aperture, and focus distance 🙂 :
http://www.dofmaster.com/dofjs.html
Yes.
You could also use the wider aperture to lower your ISO and maybe reduce noise. Three stops – f/5.6 – would let you shoot at 1/1000 and ISO 160.
And as aajax says, bracket. It would take a few seconds to try some other exposures.
Good advice. 🙂
Exposure looks pretty good in photo, above. Not sure how much of viewfinder is taken up by moon at 300mm on a A6000, but if one used spot metering on the moon itself, I'm thinking that exposure would be pretty darned close at zero exposure compensation. I've never done astrophotography, but I would guess that without a tracking tripod, the moon would move quite a bit every second, so that very fast shutter speeds would be of great benefit?
I don't know. A very rough, and possibly wildly inaccurate calculation suggests it moves about three feet in 1/1000 of a second. I doubt that's going to get much blur. Maybe the camera steadiness will help.
OK. Let's see: Moon orbits Earth at ~ 2200 mph. Meanwhile, Earth is rotating at ~ 1000 mph at equator. I have no clue whatsoever how these two orbital rotations relate to one another as vectors. So, yup – about 4.9 feet per 1/1000 second worst case, so at 239,000 miles… I think you are right, and I was wrong. 🙂
Very cool!
Thanks everyone! Great advice.
The crowds in this photo are even more sparse than the inaugural pictures posted by the NPS. Did you doctor it to further deny Trump the glory that is rightfully his?
Back when my family had a summer place far from light pollution, down near a shore on a peninsula that was very sparsely populated in the off-season, I kept a nice telescope, and I was very familiar with the night skies, read the Celestial Events column at the end of Natural History each month, etc. There were four guaranteed crowd pleasers, over a May or October weekend: 1) the four Gallilean moons of Jupiter, 2) the rings of Saturn, 3) showing the star in the bend of the Big Dipper's handle to be a binary, and perhaps the most oooohs and ahhs of all, 4) a full moon, up nice and tight, with all that glorious topography.