DataAstro - Eyepiece

Simulation of TFoV for selected eyepieces

1) among these examples, identify a target EP that matches/is closest to one of yours;

2) full screen the picture and dim your PC/phone screen such that M42 AND the sky are the most similar to what you see through your matching one. Viewing it on a dimmed screen in a dark room without light will give you the best experience.

3) zoom-in on the picture such that the FOV of the target EP gives the feel you get through your matching one; You can also achieve the zoom-in effect by holding the picture close to one eye, but you will lose focus and keep that distance consistent for the next step will be challenging;

4) keep this zoom-in ratio and move the picture around, you should be able to feel the difference.

A brief introduction

The following pictures are generated based on 1200mm-focal length telescopes. The data of the eyepiece field stop has been justified based on actual measurements by our peers. The contract is adjusted for M42 based on exit pupil.

Tech part: The TFoV is likely to be accurate based on math and eyepiece producers’ data. The contrast is adjusted following #9 post by Ferris (despite that people have proved that contrast does not vary...) while the brightness of the M42 core is kept constant. However, the M42 in the photo used here is brightness-saturated, so it is much brighter than the actual view and cannot be adjusted within the saturated region.

The picture shows the best possible field size of the EPs in theory. Actual view/clarity, however, may degrade significantly near the edge for some EPs. If a 100-degree eyepiece is blurry by 90% FOV, it is not any better than an 82-degree one that is sharp to the edge.

M42

The Moon

The Jupiter

Where we are today

We are working on including more popular objects and eyepieces.

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