80 replies to this topic

[NathanL]

Thermal goggles, the better ones you can adjust how bright the display is. Adjust down to a light glow and you can pick up the heat off a tripod leg and other equipment. Adjust up and it's like looking at a q-beam that can shine through walls. Price is a drawback obviously.

Edited by NathanL, 06 April 2023 - 05:20 AM.

[russell23]

Actually what matters is that no one is discussing the brightness of their skies, the telescope they're using, the objects they're observing. Red is measuring things and discussing the sensitivity of his eyes in terms of mpsas. 

 

Without a frame of reference, this discussion is mostly apples and oranges..

 

That was the purpose of my post, let's get some context. Does anyone want to share this information?

 

 

 

Jon

Jon,

 

I don't have that information.   I'm not spending my time hunting down faint PGC galaxies with a 20 inch dob.  I spend about 90% of my deep sky observing time looking at objects well within the light grasp of my scope.  When I study those objects I do spend time hunting for the faintest detectable details.  The remaining 10% of the time I spend searching for fainter stuff closer to the scopes limit.   

 

The problem is you're never going to get sufficient data here to reliably answer these questions.  An individual's eyes are a huge variable.  What percentage of observers are measuring the brightness of their sky every night.  I don't even know what you need to do that because it doesn't matter to me.  I go out.  I observe.  The skies are what they are.   Sometimes I only get 15 minutes of observing before clouds roll.  Typically on work nights and cold winter nights I observe for 90 - 120 minutes.  On weekends and during the summer I will observe for 3 1/2 - 5 hours.

 

There are so many variables just in all that. 

 

What I consistently (without exception) find regardless of any of the other stuff you are asking for is that I cannot see well enough to read a chart without straining or even find a black cap dropped in the grass when using my red light.  When I use an amber light I can see well enough to quickly find the dropped cap or the reference stars for the target on the chart.  If I use the red light I spend more time trying to find what I'm looking for on the ground or chart, have eye strain, and it more negatively impact my night vision.

 

And the thing is - whether I observe for 30 minutes or 5 hours it is exactly the same.  I provided my last little experiment simply to provide some numbers for how much difference in impact I was seeing - which seems to be about 50% more recovery time with the red vs. the amber.

 

It boils down to this - everyone should use what works for them.  There is a non-negligible number of people on this thread that have said they prefer amber.  And JimK earlier provided the most homogenous test results which demonstrated under the same conditions observers had multiple different preferences.

[JimK]

Actually what matters is that no one is discussing the brightness of their skies, the telescope they're using, the objects they're observing. ...  Does anyone want to share this information? ...

I already did exactly that, earlier in this thread.  But as Dave [russell23] already mentioned, it doesn't really matter.

 

Some observers look at "eye candy" only, some look at the same objects repeatedly, some search for objects so they can complete an observing program or goal (all objects on a chart, or brighter than some magnitude, etc.), some observe targets of interest from an article they read or a particular topic, some just point their telescopes and enjoy what they see, some observe alone, others in groups.  Observers need to find use what works for them to enjoy this hobby.  However, when at a site with others, each observer *should* be considerate with regard to light management.

 

I have attended a bunch of large star parties, I have observed in small groups, and alone.  My techniques change depending on the situation: I absolutely need a light blocker when with others (i.e., a homemade Dethloff Eyepiece Shade, which I have mentioned on CN) * , and when alone I may use a blue laser pointer, depending on the ambient background light.  When looking for the faintest objects, I may use an eyepatch on my observing eye for a few minutes before viewing, and take notes using a voice recorder.  It all depends.

 

I'm not keen on discussions of the minutiae of dark adaptation, but I suppose some others are, and will continue to dwell on very fine points so as to extract every photon of information from our skies.  But trying to not bleach one's retina with bright light, be it green or amber or  deep red, seems prudent to facilitate those moments of "ooh" and "ahhh" that make this an enjoyable hobby.  As one CN member often says, "If you're not having fun, then you're doing it wrong."

 

* EDIT:  And I bring a pair of deep red glasses/goggles to use when someone has to leave early, minimizing the damage to my night vision from their vehicle.

 

Edit2: PS - I have seen some posts that complain about the red lines in Rukl's 1st ed of his book of Moon features being invisible using red light, yet I personally find that a non-issue because Luna is so bright that I observe with white (porch, etc.) lights on to both read the charts and not have to fumble after viewing the bright Moon.  So when observing Luna, and other bright sky objects (e.g., Jupiter, Venus, Saturn, Mars) I don't bother with red/amber or even dim lighting so I can use my colorful cones as needed.

Edited by JimK, 06 April 2023 - 01:05 PM.

[Freezout]

Edit2: PS - I have seen some posts that complain about the red lines in Rukl's 1st ed of his book of Moon features being invisible using red light, yet I personally find that a non-issue because Luna is so bright that I observe with white (porch, etc.) lights on to both read the charts and not have to fumble after viewing the bright Moon. So when observing Luna, and other bright sky objects (e.g., Jupiter, Venus, Saturn, Mars) I don't bother with red/amber or even dim lighting so I can use my colorful cones as needed.

Funny, I was a couple of days ago observing the Moon with Ruckl atlas, and had the same issue with my red light. I didn’t notice this red figures issue previously because I most of the time use normal lights when making a Moon session. That time I don’t know why, by automatism probably I used my red light and was annoyed by the red invisibility, not thinking once that I was making my life complex for nothing !

[ButterFly]

Actually what matters is that no one is discussing the brightness of their skies, the telescope they're using, the objects they're observing. Red is measuring things and discussing the sensitivity of his eyes in terms of mpsas.

Without a frame of reference, this discussion is mostly apples and oranges..

That was the purpose of my post, let's get some context. Does anyone want to share this information?

What I find interesting is how much dimmer my tablet reads with the SQM than Red's charts. I'm reading my tablet when it measures 22.0 mpsas and darker from approximately my viewing distance. It has a deep red film made by Sirius Optical so that shifts the numbers a little. I suspect that there's a fundamental difference that explains this.

Jon

That is all better than a faith based approach. The photochemistry of the eye is fairly consistent, but perception and conception contribute above the sensation.

Testing one's own eye and brain system under actual observing conditions will be better for one's own personal neurological response to sensed light (and unsensed afterimages). Others' experiences can inform our choices of what to try next. Whether it does better or worse, or one can't tell, it's the person's own binary response that matters in the field.

Try it all out for yourself. End of the night testing is a better guard against strong negative responses ruining the rest of the night. Again, try it all out for yourself.

[Zygmo]

 Keep it diffused and dim is the main thing, using any color.