Eyepiece comparision tool

[Dave1]

One tool I find really useful in comparing eyepieces and there FOV. Is this one https://astronomy.tools/calculators/field_of_view/ . It allows you to select the object you are planning to observe. You can then iselect your telescope from a drop down list. If your telescope isn't included on the drop down menu list, then you can enter the details as a custom. You can then put in the details of the eyepiece. It allows you to compare the FOV of many different eyepieces. Taking out some of the guess work.

Thought I'd share.

 

[John]

Thats a very useful tool Dave

Thanks also to First Light Optics for making it available

Here is the original post from them:

 

[Ricochet]

There's also a link to it under the "Resources" button at the top of the forum (or in the hamburger menu on phones/tablets).

[Dave1]

Right obviously I didn't spot those things, and thought I'd share to try and help others...

[Alien 13]

I do like the fact that we can add data for new scopes/lenses/cameras and eyepieces.

Alan

[John]

2 hours ago, Dave1 said:

Right obviously I didn't spot those things, and thought I'd share to try and help others...

Thats good - the more they get promoted, the more folks will find them

[ronin]

I just take the object size then work out the magnification required to get that field of view in whatever eyepieces I expect to use. Sort of:

M42 is a degree, in the BST's that means 60x magnification, and in the Bresser to get 60x means a 10mm eyepiece. So the 12mm BST should squeeze it all in with a small amount to spare. So I drop the 18mm in to be safe and have the 12mm to hand. Determination takes a few seconds when and if I manage to convince brain cell 1 and brain cell 2 to work together, there isn't a 3. What do people do when outside and no PC to hand?

The arithmatic I find easy and I can be using anything from a 350mm FL scope to a 1500mm FL scope, and 4 options between.

[Dave1]

Personally, I only use this tool to compare eyepieces before I purchase them, I really don't need this tool outside with me whilst observing, or any maths to figure out which eyepiece I should use. I will simply find the object I will to view with a very low powered eyepiece, and then swap out for the eyepiece I deem most appropriate.