Eyeball foggingPosted By Dmitri Kulginov |
What, your eyeballs fog?!
Dmitri
Dmitri
Posts Made By: Dmitri Kulginov
June 22, 2005 07:44 PM
Forum:
Eyepieces
June 22, 2005 09:14 PM
Forum:
Eyepieces
Eyeball foggingPosted By Dmitri Kulginov |
Well, the eye is surrounded by a layer of air with elevated humidity. Due to this fact, the dew point temperature near the eye is higher than in the ambient air. This manifests itself in dewing of the eyepiece in a proximity of the eye.
If you rise the temperature of the glass, by a heater or by holding the eyepiece in a warm pocket, you might place its temperature above the dewpoint of the ambient air, but it might still be below the dew point in the eye's own "atmosphere". If you warm the glass yet more, the dew point will shift yet higher and the dew will not fall even near the eyeball.
This hopefully makes it clear that it you make the eyepiece warm enough, the dew will not appear on it no matter what.
Dmitri
If you rise the temperature of the glass, by a heater or by holding the eyepiece in a warm pocket, you might place its temperature above the dewpoint of the ambient air, but it might still be below the dew point in the eye's own "atmosphere". If you warm the glass yet more, the dew point will shift yet higher and the dew will not fall even near the eyeball.
This hopefully makes it clear that it you make the eyepiece warm enough, the dew will not appear on it no matter what.
Dmitri
June 25, 2005 09:17 PM
Forum:
Equipment Talk
Wavefront error questionPosted By Dmitri Kulginov |
An objective should focus all light within an Airy disc because this image can be magnified by the eyepiece to any extent. An eyepiece should only focus light within a couple of minutes of arc because this is not magnified further, and the eye cannot resolve smaller detail. Hence, an eyepiece doesn't need to be diffraction limited. Optimally, it should cancel objective's aberrations like coma and field curvature.
Dmitri
Dmitri
July 12, 2005 05:15 PM
Forum:
Deep Sky Observing
Stock 2Posted By Dmitri Kulginov |
Stick man cluster
Dmitri
Dmitri
July 15, 2005 03:54 PM
Forum:
Deep Sky Observing
M51 Supernova Visual observationPosted By Dmitri Kulginov |
Michael,
Thanks for a great report!
Dmitri
Thanks for a great report!
Dmitri
July 22, 2005 02:55 PM
Forum:
Deep Sky Observing
Nagler 31mm on a C11 for DSO ?Posted By Dmitri Kulginov |
http://www.astromart.com/articles/article.asp?article_id=276
is about Nagler 31 in C14, but C11 shouldn't be too much different.
Dmitri
is about Nagler 31 in C14, but C11 shouldn't be too much different.
Dmitri
July 26, 2005 07:01 PM
Forum:
Film Astrophotography - Imaging and Processing
WIDE FIELD shot of M51Posted By Dmitri Kulginov |
Awesome, Peter. Puts things in a cosmological perspective. Thanks for sharing.
Dmitri
Dmitri
July 29, 2005 03:53 PM
Forum:
CCD Imaging and Processing/Solar System
Light Cup first Lunar photoPosted By Dmitri Kulginov |
I think 4" is too little for the Moon, and it shows in the image.
Dmitri
Dmitri
July 30, 2005 11:17 AM
Forum:
CCD Imaging and Processing/Deep Sky
Veil last night in colorPosted By Dmitri Kulginov |
There are more stars inside the loop.
Dmitri
Dmitri
August 1, 2005 07:18 AM
Forum:
Deep Sky Observing
An interesting experiment and some SSO'sPosted By Dmitri Kulginov |
Inge,
You can always darken the skies by magnification, but sometimes you have to have goto for that
Vega, Arcturus and Altair would be sufficient for alignment. I observed some 20 double stars in Bootes alone on the 11th of July, and I could only see three or four stars when I started.
Dmitri
You can always darken the skies by magnification, but sometimes you have to have goto for that
Vega, Arcturus and Altair would be sufficient for alignment. I observed some 20 double stars in Bootes alone on the 11th of July, and I could only see three or four stars when I started.Dmitri
Funding Member
