Ok, I'll bite.... For what it's worth. I've not had luck with these calculators matching my observations. I tend to see about 2 magnitudes fainter stars...
19447
Event Horizon
eventhorizon...
Jul 1, 2009 4:24 pm
Well, the copied formatting from the mag cac site did not transfer like it looked when I pasted it in my email, but, the two conditions are: 20" Telescope,...
19448
Robert Houdart
rhoudart
Jul 1, 2009 5:23 pm
Steven, You must be very experienced observer with excellent eyesight at a pristine location. Very few people reach magnitude 20 with a 20" scope. Your numbers...
19449
Nils Olof Carlin
nilsolofcarlin
Jul 1, 2009 6:19 pm
Steven You will find Schaefer's original article at: ...
19450
Event Horizon
eventhorizon...
Jul 1, 2009 6:20 pm
Hi Robert, I have been at this observing thing for a while. With the things I've seen I'd say, given my vision, scopes, nights of exceptional seeing, that I...
19451
Event Horizon
eventhorizon...
Jul 1, 2009 6:40 pm
Thanks, if there are adverse effects by altering the exit pupil for having used high power, though the result comes closer to my observations and puts the...
19452
pensack1
Jul 1, 2009 9:54 pm
By modifying the html for Bogen's Schaefer-derived to correspond to the correct reflectivity of my telescope's mirrors, and also modifying the pupil diameter...
19453
eventhorizon2112@...
eventhorizon...
Jul 1, 2009 10:22 pm
Well, I don't know if I'm NELM of 9.0. It's high for sure as I can still use an eyepiece combo that produces 8.7mm exit pupil and my iris does not...
19454
Nils Olof Carlin
nilsolofcarlin
Jul 2, 2009 8:22 am
Don, While I'm well familiar with Schaefer's 1990 paper, the 1998 article in S&T seems to be missing from my collection, and I don't know the details of ...
19455
Nils Olof Carlin
nilsolofcarlin
Jul 2, 2009 8:30 am
Don, While I'm well familiar with Schaefer's 1990 paper, the 1998 article in S&T seems to be missing from my collection, and I don't know the details of ...
19456
Nils Olof Carlin
nilsolofcarlin
Jul 2, 2009 8:40 am
Sorry about the double messages - the difference was that in the first version, I incorrectly stated that the experience factor was not included in Robert...
19457
bob_hill12000
Jul 2, 2009 2:07 pm
Hi Robert, Steven's experience with his 20 matches mine with my 20. When going after some of the very dim targets that I do, I have seen that I can detect...
19458
Event Horizon
eventhorizon...
Jul 2, 2009 11:20 pm
It's interesting that the visual recovery of Halley was brought up. I too remember reading about that observation and just a few weeks ago I looked up the...
19459
Nils Olof Carlin
nilsolofcarlin
Jul 3, 2009 7:40 am
looking again art Schaerfer's article (it must have been over 10 years since last time I perused it), I find these comments, that might be very relevant ...
19460
Robert Houdart
rhoudart
Jul 3, 2009 10:15 am
Nils Olof, ... In the calculator the NELM deals with that, any value larger than 7.0 is interpreted by the Javascript as a perfect sky plus a sensitivity...
19461
pdebaan
Jul 3, 2009 10:55 pm
Hi all, have a great 4th, Anyone made a Binocular 2 mirrorred Newtonian ? Peter...
19462
Christopher Todd
zaphodhearto...
Jul 4, 2009 12:16 am
Not sure if anyone on this list has made one, but there's a whole Yahoo group devoted to that - binewt. Chris...
19463
pensack1
Jul 4, 2009 1:54 am
Nils, Replies below. Don ... Wasn't that a 1989 article? ... Look at the html code behind this page: http://www.go.ednet.ns.ca/~larry/astro/maglimit.html In IE...
19464
pensack1
Jul 4, 2009 2:04 am
Robert, There is dark adaptation and there is dark adaptation. To wit: in the old days, serious observers doing threshold observations would often cover their...
19465
bigdob@yahoogroups.com
Jul 4, 2009 2:06 am
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the bigdob group. File : /Collimation...
19466
John Mahony
jmmahony
Jul 4, 2009 2:51 am
Yes, although it's hardly big enough to qualify for this group: <http://www.stargazing.net/wvas/BigBinocs/Binocular.htm> -John...
19467
Robert Houdart
rhoudart
Jul 4, 2009 3:52 am
Don, ... In the new calculator you can enter your true pupil diameter instead of relying on the automatically calculated age-dependent value. Other changes...
19468
Nils Olof Carlin
nilsolofcarlin
Jul 4, 2009 9:00 am
... Seems many observers are not aware of this, but you will notice that after looking at a dark branch against the dark sky, moving your gaze shows there is a...
19469
Nils Olof Carlin
nilsolofcarlin
Jul 4, 2009 9:05 am
Don, ... You're right - I copied the wrong year from somewhere I can't recall now. ... While this is possible, I just don't think it's fair to the user to...
19470
pensack1
Jul 4, 2009 4:06 pm
Nils, Regarding the html code, here are some changes to make to adjust for your experience: 1) if (form1.Teletype[0].checked) { var DS=0.21*D; var...
19471
Nils Olof Carlin
nilsolofcarlin
Jul 4, 2009 8:07 pm
Don, thanks a lot for this - it helps to have something substantial to discuss. ... It would be nice to choose from standard valuer or calulate the recipe for ...
19472
pensack1
Jul 5, 2009 4:30 pm
Nils, I think that an experienced observer will always see more through a scope than an inexperienced observer--in all conditions. So experience is important. ...
19473
jpcannavo
Jul 7, 2009 11:29 am
While enjoying the discussion, I had to comment... Glad to see reference to this classic cartoon by Sidney Harris. I first saw it a few decades ago in American...
19474
bpjabber
Jul 7, 2009 5:50 pm
New to the group and while my 10" dob would hardly qualify as big, I regularly attend new moon weekends in Chiefland, FL where there are very dark skies and...
19475
E. Allen Davis
epc398
Jul 7, 2009 7:20 pm
Some of my buddies and I from here in NC are planning to go this year in November....everyone says it is a great event. allen E. Allen Davis ...
