Shooting images through window pane glass

[solarblast]

For a simple starter, I'm curious what the transparency of pane glass is.

Moreover, we have a domed observatory and one of the two shutters (lower) has a common window pane about 3' on a side. In fact, there are three elements of the shutter area; upper, lower, and a wind screen (below the lower shutter). Typically, we do not use the wind screen. When used it can be attached to the lower shutter, and drawn up from a spool on which the screen is wound. In this format, it has the advantage of keeping air from circulating into the dome, and providing air stability.

It recently was brought to my attention that maybe the wind screen should be in use because of the stability just mentioned. However, that may not be good if the window transparency is say 70-80%. The CCD camera on the telescope is use for astrometry, so b/w is fine. No need for color photography. However, it may be that the glass might flex when the inside and outside temps are different. Possibly dirt on the window may be a factor. I have do idea yet if this would cause trouble.

Comments are welcome any of this?

 

[mishima]

Hi, I don't have any input to your questions but I was curious to see an image of your observatory with the wind screen from the description.

 

[glappkaeft]

The problem with window panes are other optical qualities (the big problem is not transparency but that they aren't flat, not coated, introduce color errors etc.) compared with optics. One could use optical quality glass but that would be very expensive.

Many years ago a guy in Kalix in northern Sweden built an observatory with a removable Mylar "window" so that he could observe when the temperature outside is -40 degrees C or colder. Mylar can have quite decent optical quality (see http://www.jstor.org/discover/10.2307/40680382?uid=3738984&uid=2&uid=4&sid=21102282123167 ).

 

[solarblast]

Thanks. Yes, I recall the mylar approach.

As it turns out, my question is defunct. A circuit card that controls the shutter is more limited than I thought.

I have no photo of the wind screen in the proper position. I am providing one when it was out of the box that contained it.

 

[pmacias]

I can provide some insights into the transparency of pane glass and its potential impact on shooting images through it.

First, the transparency of pane glass can vary depending on the type and quality of the glass. Generally, pane glass has a transparency of around 90%, meaning that 10% of light is reflected or absorbed by the glass. However, this can be affected by factors such as the thickness of the glass, the presence of coatings or impurities, and the angle of incidence of the light.

In terms of shooting images through pane glass, the transparency should not be a major concern as long as the glass is clean and free from scratches or other defects that could affect image quality. However, it is important to note that shooting through any type of glass can introduce some distortion or loss of clarity in the image. This is due to the refraction of light as it passes through the glass, which can cause some blurring or color shifts.

In terms of the wind screen and its potential impact on image stability, it is important to consider the potential for vibrations or movement caused by changes in air pressure or temperature. If the wind screen is not securely attached or if there is a significant temperature difference between the inside and outside of the dome, this could potentially affect the stability of the images being captured. Additionally, dirt or debris on the window could also cause similar issues.

In summary, while the transparency of pane glass may not be a major concern, it is important to ensure that the glass is clean and free from any defects that could impact image quality. Additionally, the use of the wind screen should be carefully considered to minimize any potential for vibrations or movement that could affect image stability. Further experimentation and testing may be needed to determine the best setup for optimal image quality in your specific observatory.