SPC880N

[iamzoso60]

I have now got a SPC880N web cam, flashed with the 900 software, which I have tried with my Skymak 127, but was wondering if anyone knows what sort of mag or eyepiece equivalent I am getting?

[Doc]

I think I read somewhere it was equivilant to a 6mm eyepiece.

[northernlad]

I agree with Doc - it's the equivalent to a 6mm eyepiece.

[themos]

Forget magnification, it's a concept that does not apply to imaging. What you are asking is what is the size of the field captured by the sensor and which eyepiece will give you that field of view. The 6mm answer is good but it obviously does not apply to Nagler-type 6mm eyepieces which have a much larger FOV than a 6mm Plossl or Orthoscopic.

The approximate formula, as far as I can make out is

(eyepiece focal length in mm) = (size of sensor in mm)*180/ (pi * (eyepiece FOV in degrees) )

The sensor size is 4.60*3.97mm, a Plossl has about 50 degrees FOV so the formula gives 5.3x4.5 mm of focal length for the two dimensions as the eyepiece equivalent.

If you use Nagler eyepieces, then the focal lengths that would give you the same FOV would be 3.2x2.8mm, as they have an eyepiece FOV of 82 degrees.

[TheThing]

I think the idea is which EP would the webcam give the equivalent FOV as. 6mm is sometimes suggested, but it varies between 6mm and 10mm, depending on the webcam.