to diagonal, or not to diagonal? tis the question!

[bmc]

I recently bought an zwo asi 120 mm, and the other day wS the first opportunity to use it. It was day time and I was attempting to image the sun. I got Helios in my field of view, and in focus on my scope. Then I removed my EP & diagonal, and replaced it with my camera. I don't know if i'm just using the wrong settings on firecapture, but the recorded image was way out of focus. Was this because I inserted the camera directly into my ota? I assumed that the less glass/mirror the image would go through the better. Am I wrong?

[ronin]

The camera will not have been at the focal plane of the scope, so out of focus.

You will have to take the eyepiece out to fit the camera in than refocus if there is sufficent travel on the focuser to get the camera at the focal plane.

If you took the eyepiece out and dropped in the camera I would expect that the focuser would need to be wound in quite a bit.

If you removed the diagonal as well then you would need an extension tube to compansate for the missing diagonal, basically with both removed I doubt that you would ever obtain a focused image on the camera.

Best is leave the diagonal in, swap eyepiece for camera and refocus the scope to get a sharp omage, then get the .avi file.

But unless very very fortunate (about as rare as finding hens teeth in a pile of rocking horse dung) the camera will not be in focus when it replaces the eyepiece.

[Alien 13]

A diagonal adds about 2" to the image train so either the focusser needs to be moved by that amount or you need to fit an extension ring.

Alan