Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Do 15 x 70 binos capture more light than a 70mm scope?


WayBig

Recommended Posts

Is this a daft question….

Logically I would think that they capture twice as much as a 70mm scope – which would be the equivalent area to a scope with an aperture of 99mm, if you calculate the combined surface area of both eyepieces.

Is it that simple, or is there anything funky going on that makes this not the case?

Thanks

Link to comment
Share on other sites

The logical answer is: they capture the same light because if they capture twice as a single 70mm, when we close one eye, picture of object must dim to half. And it doesn't.

On the other hand, the truth is that, the brain is more pleased with double pictures of one object, because this is the natural aspect when we look with both eyes. So the pictures of binoculars look like have a little more light. And have a little more 3D feeling.

We know this also, from the use of good quality binoviewers. Pictures of bright objects like planets, moon, globular clusters, are superb.

Link to comment
Share on other sites

Well, that they capture twice the light is hardly going to be a debating point. They obviously do. But the fact that they funnel into one eye each changes everything and, very clearly (as Pleiades and Gaz say) the effect is not at all that of doubling the area of aperture into a single ocular. The result may be more pleasing and there may be a psychological 3D effect but if you want twice the light grasp then go for a scope with twice the area of glass.

I think it inconceivable that the 3D effect is actually any more than psychological because of the geometry of the situation. You have a triangle with a baseline the width of the bins that extends, say to M31, 2.5 million LY. That is going to look more like a line than a triangle!! And can you tell, by looking through bins, that M31 is nearer than M101? No, any 3D effect must be of psychological origin but that is not to say it isn't worth having. Far from it.

Olly

Link to comment
Share on other sites

No, any 3D effect must be of psychological origin but that is not to say it isn't worth having. Far from it.

Olly

Exactly! It is psychological and wonderful. Also something we forgot to mention is that the brain doesn't works like a ccd. It can’t add the light gathering from each eye (or if they look the double time at an object, object doesn’t look brighter).

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.