Re: [Utah-astronomy] The sun 3-30-2013
Back when I did a lot of solar viewing and photography with an 8" I used to cover my head and the end of the scope with a blanket. Often it got pretty hot. -- Joe ------------------------------ On Sun, Mar 31, 2013 1:58 PM MDT erikhansen@thebluezone.net wrote:
I was not referring to air temp but rather being shielded from the suns glare, although a big umbrella with a hole in it was nice on hot days. With a brimmed hat I was always bumping the eyepiece. Of course, the drawback is you need a sturdy mount.
Erik, the problem with the binoviewer in daylight isn't one of comfort.
Yesterday was on the cool side and quite pleasureable. I wear a brimmed had when observing the sun, and have been known to set up in the shadow of a building when the geometry works out.
The difficulty with a binoviewer in daylight is that the pupils of your eyes are as small as they ever get. Combine that with long eye relief of a low-power eyepiece and a small exit pupil from high power (thanks to the relay Barlows) and a small objective aperture, and you have two very small "sweet spots" that you have to align perfectly in order to use the binoviewer.
The net result is a pair of very small virtual images floating far from the eyepieces, that have to align perfectly with a pair of small eyeball openings. Inter-occular spacing must be dead-on, and your head placement must be dead-on. A shift of only a millimeter or two means you lose one or both sides of the image.
Can you hold your head still within a millimeter for 10 to 30 seconds? I find it VERY difficult if not impossible, outdoors perched on a chair.
A sun shade won't affect this problem much, if any. Your pupils will still be very small and most folks don't have the body control of a Hindu yoga master.
Using large aperture will help. That will increase the size of the final exit pupil, so even if the observer's pupils are completey contracted, there is more "wiggle room" for head positioning. That's why at SPOC, I'd rather use a binoviewer on the Andy scope for public viewing, than on a PST or double-stack. And a double-stack image is inherently dimmer than the PST in the first place. In a binoviewer it would be even dimmer.
Unless your solar imaging system provides a large exit pupil, binoviewers are much easier to use at night, when your entrance pupil is open 5 to 7mm. Head placement is not as critical, by a long shot.
On Sun, Mar 31, 2013 at 9:01 AM, <erikhansen@thebluezone.net> wrote:
I've always found a big sun shield to be essential for pleasurable sun viewing.
Here's the pic of the PST/binoviewer setup, on my small GEM:
http://i260.photobucket.com/albums/ii24/JethroTull1958/ATM/PSTampbinoviewer0...
It was pretty neat seeing the sun in H-a with both eyes, a first for
me.
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
Tried a hood also, very uncomfortable and you don't want to share it with the public. I do think I got more glare protection with an umbrella compared to a hat, the bigger the shadow the better the glare reduction. The umbrella made it easier for inexperienced users also.
Back when I did a lot of solar viewing and photography with an 8" I used to cover my head and the end of the scope with a blanket. Often it got pretty hot. -- Joe
------------------------------ On Sun, Mar 31, 2013 1:58 PM MDT erikhansen@thebluezone.net wrote:
I was not referring to air temp but rather being shielded from the suns glare, although a big umbrella with a hole in it was nice on hot days. With a brimmed hat I was always bumping the eyepiece. Of course, the drawback is you need a sturdy mount.
Erik, the problem with the binoviewer in daylight isn't one of comfort.
Yesterday was on the cool side and quite pleasureable. I wear a brimmed had when observing the sun, and have been known to set up in the shadow of a building when the geometry works out.
The difficulty with a binoviewer in daylight is that the pupils of your eyes are as small as they ever get. Combine that with long eye relief of a low-power eyepiece and a small exit pupil from high power (thanks to the relay Barlows) and a small objective aperture, and you have two very small "sweet spots" that you have to align perfectly in order to use the binoviewer.
The net result is a pair of very small virtual images floating far from the eyepieces, that have to align perfectly with a pair of small eyeball openings. Inter-occular spacing must be dead-on, and your head placement must be dead-on. A shift of only a millimeter or two means you lose one or both sides of the image.
Can you hold your head still within a millimeter for 10 to 30 seconds? I find it VERY difficult if not impossible, outdoors perched on a chair.
A sun shade won't affect this problem much, if any. Your pupils will still be very small and most folks don't have the body control of a Hindu yoga master.
Using large aperture will help. That will increase the size of the final exit pupil, so even if the observer's pupils are completey contracted, there is more "wiggle room" for head positioning. That's why at SPOC, I'd rather use a binoviewer on the Andy scope for public viewing, than on a PST or double-stack. And a double-stack image is inherently dimmer than the PST in the first place. In a binoviewer it would be even dimmer.
Unless your solar imaging system provides a large exit pupil, binoviewers are much easier to use at night, when your entrance pupil is open 5 to 7mm. Head placement is not as critical, by a long shot.
On Sun, Mar 31, 2013 at 9:01 AM, <erikhansen@thebluezone.net> wrote:
I've always found a big sun shield to be essential for pleasurable sun viewing.
Here's the pic of the PST/binoviewer setup, on my small GEM:
http://i260.photobucket.com/albums/ii24/JethroTull1958/ATM/PSTampbinoviewer0...
It was pretty neat seeing the sun in H-a with both eyes, a first for
me.
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
On 31 Mar 2013, at 14:47, Joe Bauman wrote:
Back when I did a lot of solar viewing and photography with an 8" I used to cover my head and the end of the scope with a blanket. Often it got pretty hot. -- Joe
I got a little fancier. I had a cloth "tube" made of black cloth with elastic on the ends. I'd push my head in one end and put the other end over the eyepiece. Worked great and I figured I could always also use it should I ever get a job as an executioner. :) patrick
Come to think of it, we are made of meat and you hate meat. You’d make a good executioner. Dave On Mar 31, 2013, at 4:42 PM, Patrick Wiggins <paw@wirelessbeehive.com> wrote:
On 31 Mar 2013, at 14:47, Joe Bauman wrote:
Back when I did a lot of solar viewing and photography with an 8" I used to cover my head and the end of the scope with a blanket. Often it got pretty hot. -- Joe
I got a little fancier. I had a cloth "tube" made of black cloth with elastic on the ends. I'd push my head in one end and put the other end over the eyepiece. Worked great and I figured I could always also use it should I ever get a job as an executioner. :)
patrick _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
You guys understand that glare reduction and shading the observer has nothing to do with the difficulties of using a binoviewer in daylight, right?
Sure it does. If you are covered by a cloth so people can't see you using a binoviewer, then people can't point out that your pupils are too small to make it easy. Dan -- Sent from my iPhone. Please pardon any mispelings or errors. On Mar 31, 2013, at 5:38 PM, Chuck Hards <chuck.hards@gmail.com> wrote:
You guys understand that glare reduction and shading the observer has nothing to do with the difficulties of using a binoviewer in daylight, right? _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
Ah, the old "You can't see me 'cause I have my eyes closed" argument. On Mar 31, 2013 5:51 PM, "Daniel Holmes" <danielh@holmesonics.com> wrote:
Sure it does. If you are covered by a cloth so people can't see you using a binoviewer, then people can't point out that your pupils are too small to make it easy.
Dan
-- Sent from my iPhone. Please pardon any mispelings or errors.
On Mar 31, 2013, at 5:38 PM, Chuck Hards <chuck.hards@gmail.com> wrote:
You guys understand that glare reduction and shading the observer has nothing to do with the difficulties of using a binoviewer in daylight, right? _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Send messages to the list to Utah-Astronomy@mailman.xmission.com
The Utah-Astronomy mailing list is not affiliated with any astronomy club.
To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
participants (6)
-
Chuck Hards -
Daniel Holmes -
Dave Gary -
erikhansen＠thebluezone.net -
Joe Bauman -
Patrick Wiggins