Exit pupil calculation

[Caldwell 14]

Hi all.

 

If someone couple help me calculate my exit pupils please I would appreciate it, I can't for the life of me work it out. My scope is a Altair Astro Starwave 102 ED R and a set of 68 and 82 degree Explore Scientific eyepieces at 4.7, 6.7, 11, 14 and then 20 and 28 mm. It's the 4.7 and 6.7 and 28 mm I would like to know if someone could help me.

[TerryMcK]

Hi Carl. Goto http://astronomy.tools/calculators/field_of_view/ and put your scope/eyepiece combination in. Choose a solar system object like Jupiter and it will work it out for you. If your exact scope and eyepiece isn't there then just input the focal length/aperture etc.

 

Here's an example

 

[TerryMcK]

6 hours ago, Caldwell 14 said:

Hi all.

 

If someone couple help me calculate my exit pupils please I would appreciate it, I can't for the life of me work it out. My scope is a Altair Astro Starwave 102 ED R and a set of 68 and 82 degree Explore Scientific eyepieces at 4.7, 6.7, 11, 14 and then 20 and 28 mm. It's the 4.7 and 6.7 and 28 mm I would like to know if someone could help me.

 

Hi Carl,

Goto http://astronomy.tools/calculators/field_of_view/ and input your scope/eyepiece combination. Choose a solar system object like Jupiter and it will work it out for you. If your particular scope or eyepiece are not in the pulldowns then simply input the focal length and aperture.

 

Here is an example.

 

[Caldwell 14]

Thank you

[Moonlit]

On 2/28/2023 at 11:27 AM, Caldwell 14 said:

Hi all.

 

If someone couple help me calculate my exit pupils please I would appreciate it, I can't for the life of me work it out. My scope is a Altair Astro Starwave 102 ED R and a set of 68 and 82 degree Explore Scientific eyepieces at 4.7, 6.7, 11, 14 and then 20 and 28 mm. It's the 4.7 and 6.7 and 28 mm I would like to know if someone could help me.

Hi,

 

From the calculators that Terry gave you, I made a Google Sheet spreadsheet where I could jot down the vital statistics of my own telescope and EPs, and have it spit out the exit pupil, magnification and true FoV.

You can easily create one for yourself by creating a new spreadsheet somewhere (I prefer sheets.google.com) after having logged in with your Google account.
The GREEN cell are not necessary, I added them now to explain the formulas used in the cells below:
"Number" means you just punch in a number.
"Formula" means that you input a formula that calculates a number based on other cells.

For instance, it tells me that when I use my 32mm SWA eyepiece in my f/8.3 120mm refractor, the exit pupil is 3.84mm. 
And if I use my 9mm EP with a 2x Barlow (FL=2000mm due to the Barlow) the exit pupil is only 0.54mm:

"A4/F4": Exit pupil(mm) = Aperture(mm) divided by Magnification
"B4/C4": Magnification = Focus length (telescope, mm) divided by Focus length (eyepiece, mm)
"D4/F4": True Field of View (deg) = Apparent FoV of EP (deg) divided by Magnification

 

Edited March 6, 2023 by Moonlit