Fame at Last! - I'm in the Manchester Evening News!

*** Warning - A Work in Progress ****

Everything in this blog is still a work in progress as I try to backtrack to last Autumn when I started to take my journey into Astrophotography and Astronomy more seriously.  I'll be backdating some of the posts so that they appear in the correct chronological order and sequence.

The aim of this blog is to put some more detailed information about what I do and how I do it as I climb the steep learning curve that us astrophotography.  Hope fully some of the information here will be useful to others as they start their journey too.  I'll be including links to other internet-based resources which I've found useful or interesting.

So please bear with me whilst I write the posts and upload the photos and I'll remove this message once the site is fit to be viewed :) Once that is done it will be updated as I do each new set of shots.

Thanks for reading.

Martyn (GeekTeacher Astro)

Shooting For The Moon

Recently I've had a few people asking about the camera settings for photographing the moon in a single shot. As cameras have different features, I can only tell you what I use and what works for me on my Nikon D500 DSLR, but it will give you something to aim at - here goes:

1. Use a tripod if at all possible
2. Use a shutter release cable if possible, if not use the self-timer set to at least 3 seconds
3. Also set the shutter delay to 3 seconds if possible
4. Put the camera in full manual mode
5. Turn off autofocus and image stabilisation on the lens
6. Choose single point or centre-weighted metering
7. Set the ISO to 100
8. Set the aperture to f/11 (Looney 11 rule)
9. Use 'Live View' on the back of the camera to zoom in on a crater or the edge of the moon to get the best focus position
10. Focus manually by turning the lens focus ring back and forth until the image is sharp
11. Adjust the shutter speed until the exposure looks right starting at about 1/125th second
12. Press the shutter release button to take the shot.

It is possible to use autofocus with the moon, but it's sheer brightness and clouds can cause it to try to refocus, so I usually avoid it. The best moon shots are usually taken either side of the full moon, or in the waxing and waning gibbous and crescent phases, when a bit of shadow and the sun's position help to bring out the surface details. Photos taken of the full moon tend to look very flat with the direct sunlight hitting the surface.

Hope that helps.

Waxing Gibbous Moon, Again! (4/5/20)

Here's a shot of last night's waxing gibbous moon, but with a difference. I've tried using PIPP to convert a short video of the moon into separate TIF files which can then be stacked in AutoStakkert3, but without much success.  I seem to get much better results from single shots only processed in Photoshop. This image is a stack of eight separate shots blended together using only Photoshop.   However I must admit that this one looks a tad sharper than the single shot shown below it, although it has gained a bit of a purple tinge, which I can remove if necessary.

Below is just one of the single shots used to make the above image:

The stacking process I used in Photoshop was as follows:

1. Choose File>Scripts>Load Files into Stack
2. Click Browse and select all the files you want to stack together
3. Tick the 'Attempt to Automatically Align Source Images' checkbox and then OK
4. Then in Photoshop, select all the layers
5. Choose the 'Lighten' blend mode.
6. Process further if required and then save.

Craters on the Moon

Today I used Wikipedia to compile a list of crater photos in order to learn some more of their names.

A Closer View

Last night was a bit of an experiment. I had planned to do some Deep Sky imaging (galaxies, nebulae and star clusters) but because the clouds rolled in, I ended up only doing a few moon shots. I wanted to try using my QHY5P-IIC guide scope camera on my Skywatcher 200P telescope for getting some closer views of the moon. This camera also has a use as a planetary camera. I got all this stuff in a secondhand bundle with my mount last October and haven't used it until now. Little did I know how difficult it was going to be.

First of all I didn't bother with tracking as I couldn't see Polaris to do my polar alignment. Instead I just moved my equatorial (tracking) mount manually as a tripod. At such high magnifications it was so hard to even find the moon as I wasn't sure about where the focus was or even if I had the right number of extension tubes necessary to be able to focus this camera on my telescope.



I captured these images in SharpCap which also has to be used to focus the camera as, a bit like a webcam, it has no screen. Focusing caused the scope to wobble and so I had to turn the wheel a bit and then wait while it settled before making another small adjustment - very hit and miss.

 

But in the end I managed to get these two videos of the moon moving past my scope. Focusing probably could have been sharper and I didn't bother to alter any image quality or colour settings in SharpCap, which is something I'll look into next time.

Y.A.M.S.

Y.A.M.S. stands for Yet Another Moon Shot.  I often take shots of the moon when other plans have gone by the wayside. It's always a good fallback. Tonight I had planned to do a full evening of Deep Sky Object (DSO) shots because this afternoon the weather looked to be set fair for a while. But things don't always go to plan, do they?

The moon appeared early in the afternoon as a very faint object in the sunny blue sky, so I really had to ramp up the contrast and brightness to get anything worth looking at. I suspect you will either love or hate this image of the daytime moon.

Afternoon Moon (2/5/20)

After it had gone dark I started taking a few shots with my big telescope (which I am still getting used to) and the guide camera which can also be used as a planetary camera. I was pleased to have some success with this as the guide camera produces much closer images than my normal cameras do. I waited for Polaris to appear out of the clouds that had rolled in so that I could polar align my mount and get on with tonight's main business.

I waited, and waited and ... waited, but the clouds didn't lift. So I just kept taking a few more moon shots in the hope that it would lift eventually. By 11pm it had got colder and damper and there was dew beginning to form on the grass, so I decided that would be it for the night.  Of course, after I had packed everything away, the sky started to clear again, but by then I'd had enough and I decided that I just process what I'd got and call it a night.  Here's the first of them and more will follow tomorrow.

Waxing Gibbous Moon (2/5/20)

Tonight's Moon (1/5/20)

Tonight's waxing gibbous moon with various processing methods applied. Can you see any real difference - which do you prefer?

I wondered that if I cropped the shots into two halves, would the detail be clearer in each section?

I also thought it might be a good idea to dig out this old moon map I made a few months ago:

What is a Light-Year?

The distances to our nearest stars, galaxies and nebulae are huge - astronomical even!  If we used our normal units of measurement such as kilometres or miles, the number of digits would be huge too. So to make the numbers easier to handle, the concept of the light-year is used.

In 1838, the German astronomer Friedrich Wilhelm Bessel was the first to use the light-year as a unit of measurement in astronomy. He measured the distance to the binary star 61 Cygni as 10.3 light-years.

The light-year is not a unit of time although it sounds like it might be - it's a unit of length or distance, just like kilometres and miles. As defined by the International Astronomical Union, a light-year is:

'the distance that light travels in a vacuum in one year'

The light-year measures about 9.46 trillion kilometres or 5.88 trillion miles.  If these numbers were written using our normal units of length, that would be 946,000,000,000,000 kilometres or 588,000,000,000,000 miles.

I think you can see now why we use light-years rather than kilometres or miles! But even though the term is still very much in use, another larger unit the parsec (which is equal to 3.26 light-years) is actually much more popular in the scientific community.

Here are some approximate distances to some of the better-known night sky objects:

Deep Sky Objects:

• Andromeda Galaxy - 2.537 million light-years 
• Orion Nebula - 1,344 light-years 
• Betelgeuse - 642.5 light-years 
• Polaris - 433 light-years
• Capella - 42.92 light-years
• Arcturus - 36.66 light-years 
• Vega - 25.05 light-years 
• Sirius - 8.61 light-years 

Our Solar System:

• Sun - 150 million kilometres (93,000,000 miles) 
• Mercury - 77 million kilometres (48 million miles ) 
• Venus - 40 million kilometres (25 million miles) 
• Moon - 384,400 km (238,900 miles)
• Mars - 225 million kilometres (140 million miles)
• Jupiter -  778 million kilometres (484 million miles)
• Saturn - 1.44 billion km (894 million miles)
Uranus - 2.75 billion km (1.71 billion miles)
• Neptune - 4.5 billion kilometres (2.8 billion miles)

Note: all the distances to the planets in our solar system are approximate averages as they vary with orbits. The picture above does not show these distances to scale, although the relative planet sizes are correct.