Understanding Magnification?

The other night I looked @ Jupiter through a 3" scope and a 4" scope at nearly identical magnifications. For some reason the image in the 4" scope appeared noticeably larger. Is that possible? Will the same mags in different size scopes produce different image sizes? thank you, Bill

It was definitely similar magnification and not just similar eye pieces right?

Dave is right...
Bill, could you please let us know what scopes were these, their focal lengths and what eyepieces you tried?

A difference in the FOV size could also make you "believe" that one was larger than the other..., but we need more information in order to understand what happened here, since 200x in a 3" scope and in a 20" scope is always 200x, so it should be the same "size"...

Bill,

How did you determine that the power was the same?

Did you use the same eyepiece in two different scopes?

Were the scopes the same focal length?

If you used different eyepieces, you may have been fooled by different apparent field of view.

Give us some details.

While we are waiting for details--some objects may appear larger in a 4 inch scope than a three. You are, after all, getting about 78% more light. Therefore, some faint parts of the object may be showing up that did not show in the smaller scope. This would happen in a globular, and some other nebulae. If you are talking planet, moon, or small bright object, though, no--it does not happen that different scopes yield different sizes for a given object. That, after all is what a magnification number means.

Alex

The 3" was a Televue Pronto (480mm) with a 6mm ortho for 80x. The 4" was an F15 Jaegers with a 17mm plossl for 88x.

I understand all things being equal, larger aperture = more light, which = more detail. However, would the same be true for image size or should 80x in a 3" scope produce the same size image as a 30" scope?

I've got to try this again.

Thank you all for your input. This was definitely a case of pilot error. I should have paid closer attention to carefully matching the mags.

I went out tonight with a 6" F8 and the Pronto. It quickly became apparent that the same magnification would yield the same size image regardless of aperture.
P.S. I did catch the transit. Great stuff! thanks again, Bill