Simple lunar/solar kit

[WilliamAstro]

So I am thinking about achieving equipment for photographing the full disk of the moon and sun. "How are you gonna photograph the sun safely?" I will buy a solar wedge to photograph the sun safely in addition to my kit. I just want a cheap but good coated telescope that has the required focal length to photograph the entire disk of the moon and sun. The camera I will be using is Canon 550D or 600D to buy. Here is an example of what I like to expect.

Thanks and clear skies!

[Louis D]

You can't use a solar wedge with a Celestron Nexstar 127 SLT.  They can only be used with refractors.  You'll need to use a full aperture solar filter such as Baader Solar Film unless you either already have a refractor not listed in your signature line or are planning on buying one.

The 127 Mak should take fine images of the moon.  Given the 1500mm focal length and crop factor of your camera, the full moon (or sun with filter) should just fit on the sensor in one go at prime focus to avoid stitching images together.

[WilliamAstro]

8 hours ago, Louis D said:

You can't use a solar wedge with a Celestron Nexstar 127 SLT.  They can only be used with refractors.  You'll need to use a full aperture solar filter such as Baader Solar Film unless you either already have a refractor not listed in your signature line or are planning on buying one.

The 127 Mak should take fine images of the moon.  Given the 1500mm focal length and crop factor of your camera, the full moon (or sun with filter) should just fit on the sensor in one go at prime focus to avoid stitching images together.

I mean that I would like to acquire a refractor to photograph the full disk of the moon/sun (with wedge)

Edited March 12, 2022 by WilliamAstro

[Louis D]

You could go cheap with an achromat refractor and image with a green filter like a 56 green possibly combined with a 12 yellow to filter out the unfocused blue and red light.  You could then switch to grayscale in post to replicate the green channel to the red and blue channels.

Notice below for an achromat (the dotted green line) that if you restrict it to the spectrum range between 500nm and 600nm (hard to see due to the transparent background around the edges, but they're the 2nd and 4th horizontal lines from the bottom), you can get pretty tight focus.  That's roughly the color range from teal to orange.  Now notice that if you combine a 12 yellow filter with a 56 green filter, you'll do a pretty good job of selecting the 500nm to 600nm range.  Since the sun and moon are so bright anyway, you can afford to lose roughly half the light intensity within that range.  This would not be a good approach for dim, full spectrum objects.  You might not even need to stack the 12 yellow depending on the particular characteristics of the 56 green filter.