Is Field of View of 1500mm Sky-Watcher Skymax-127 large enough to observe whole moon?

[Interactive]

I am intending to buy a Sky-Watcher Skymax-127 Maksutov-Cassegrain, primarily to make a number of daytime photographic terrestrial observations ranging from 1-5.5 miles, the most distant of which is of a target at 5.5 miles that is about 5 feet in size. The distant target would have an angular size of about 0.01 degrees. To get an object of an angular size of 0.01 degrees to appear as 100pixels vertically on the APS-C sensor (22.3mm x 14.9 mm) of my Canon EOS 250D camera, I would need a telescope/lens with a focal length of about 2.1m. The Skymax 127 with a focal length of 1500mm is pretty close to the required value and if used in combination with a Barlow lens I would be able to get more than the focal length I require.

The FOV of the Skymax-127 with its 1500mm focal length in combination with the vertical sensor size of 14.9mm gives a field of view that can be derived from the following attached diagram

which gives a FOV of 0.569°.

But I would also like to make some lunar and solar observations with my system and capture images of the complete objects, and the maximum angular size of the Moon at perigee is 0.568°, so in theory the FOV of my system at 0.569 should be sufficient to gather the whole of the Moon at its largest angular size.

But I have seen a video in which someone is using a Celestron SE6, which also has a focal length of 1500mm and when using it with a Canon 60da camera with an ASP-C sensor https://www.dpreview.com/products/canon/slrs/canon_eos60da which has the same size sensor as mine, then the camera does  not seem able to capture a full view of the Moon. The video is at https://www.all-startelescope.com/video/scope-setup/nexstar-6se-dslr . The section where the Canon 60da is used is just before the end of the video and a clipped moon is shown, and then a full sized sensor camera is used to capture the whole Moon.

Does this video not suggest that my camera with its APS-C sensor coupled with the Skymax 127 with its 1500mm focal length would not be able to capture the whole Moon, despite my calculations suggesting that it would?

I understand that a reducer does not work well with a Muksatov-Cassegrain, so if I buy this telescope and use it in conjunction with my Canon250D, am I doomed never to be able to get an image of the complete moon?

Thanks in advance for any suggestions/help etc

Edited August 21, 2020 by Interactive

[vlaiv]

Even if you could do the full moon in single shot - you don't really want to do that.

First thing to note is that while Mak127 might illuminate 28mm diagonal (APS-C) - it will do it with serious vignetting. Rear opening on maksutov scopes is rather small.

Here you can see that port is less than 25mm in diameter.

Second thing is that every scope is sharpest at the optical axis. As soon as you start moving away from optical axis, you start getting aberrations. There are very few telescopes that are well corrected for large imaging circle. Small aberrations can be tolerated form DSO photography because seeing and tracking blur will mask those, but for planetary imaging - you want your scope to be really sharp.

Most people use center of the field for planetary imaging and this is the reason why planetary cameras have small sensors. How do you then create full lunar disk images? By making a mosaic of many panels.

Here is an example image taken with Mak102 which has 1300mm FL and camera that has only 8.9mm diagonal (about 1/3 of APS-C by diagonal, about 1/9 by area):

This image consists of 9 panels stitched together ...

Btw, Mak focal length depends on mirror separation - so each time you refocus - you change effective focal length. Want more focal length - add extenders so that focus position needs to change.

Alternative - get Mak102 if you really need to have whole moon in single shot.

Better alternative - get small and fast planetary camera and learn to do mosaics. I can only see whole disk image being interesting in Ha solar work as features are so dynamic that doing mosaic would not capture same image.

I once did mosaic on solar eclipse with small camera and things did not turn out that well:

I did not have time to capture whole sun and cover it with panels and moon moved relative to sun between panels so now looks a bit elongated

 

 

[Gfamily]

Moon imaged using a 32mm eyepiece and phone camera adapter

It fits