Eyepiece Projection

[great_bear]

Quick (simple) question: With "eyepiece projection" astrophotography, do you photograph through a camera lens as well, or is it just scope+eyepiece+cameraback ?

[Bizibilder]

You need the camera lens. As far as I remember from my physics, many years ago, the light rays from an eyepiece come out "parallel" so you need the camera lens to re-focus it onto the sensor (or film as it was in my day!!). I think.

[Macavity]

Hmmm... I thought it WAS: scope+eyepiece+cameraback.

<sorry> But, since I rarely remember them...

Tele Vue Optics: Imaging Methods

With a multiplicity of threads, m'Baader Hyperions lend

themselves rather well to this idea. An almost "infinite"

range of magnifications is easily available...

[MikeD]

Scope, EP, sensor.

No camra lens.

Mike.

[great_bear]

You need the camera lens. As far as I remember from my physics, many years ago, the light rays from an eyepiece come out "parallel" so you need the camera lens to re-focus it onto the sensor (or film as it was in my day!!). I think.

Not according to the Tele Vue link just posted.

Yes, the rays are parallel for visual use when focused for visual use, but I figured that this would not be the case when imaging - i.e. that one could re-focus somehow in order that the camera lens is not required.

The clue was in the name - eyepiece projection.

Yet initially my thinking was as yours - at least until I pondered further (then I gave up and wrote the original question )

Maybe the poor results I have heard people mention with regard to eyepiece projection is because they have also assumed you need the camera lens when you do not.

[Bizibilder]

Makes sense to me too now that I've seen the link. You learn something new every day!