Eddies Observing Tips

At our last meeting, Eddie Carpenter presented some observing tips.

Many members asked if these could be written up and put on the website, so here they are.

I have added my own recollections and interpretations on Eddie’s suggestions – Callum.

1. Black cloth over head and eyepiece

A black cloth over your head and eyepiece will help block out any extraneous light, and help you ‘focus’ on the object you are observing.

2. Paint EVERYTHING matt black or use cloth (flocking material) inside tube. For an open tube, use a shroud

You can improve contrast by painting everything that can be seen through the eyepiece matt black – the tube, spider, inside of eyepieces, eyepiece lens edges, diagonal edges.

3. Dark adaption

You will notice a big difference in the sensitivity of your eyes the longer you are in the dark. Even 5 minutes, but around 20 to 30 minutes are need to become fully adapted. You will loose dark adaption immediately should you look at bright white light (its a chemical reaction in your eye). Some people like to put a patch over their observing eye if they need to go into a lit area to maintain their dark adaption.

4. Cool down telescope

If you keep your telescope outdoors in a shed or observatory, it will be ready to use pretty much straight away when seeting up outside. But if you take your telescope out from warm indoors, it will take some time to cool down and give a steady image. Newtonians and SCTs are most affected, and the bigger the scope the longer time is needed for it to cool down completely.

5. Dew shield

A shield at the front of your telescope will help mitigate agains dew forming. Refractors and SCT are particularly prone. There is no need to spend lots of money on one – just black painted card or foam camping mat can be quite effective.

6. Stop down

If you have a larger telescope you may find when viewing planets or the moon you will get a better view if you stop down the telescope, but using an aperture mask over the front. This can be simply made from card. The reason for this, is that you are looking through a smaller column of atmosphere, which may be less turbulent.

7. Coloured glass or plastic

Coloured filters that screw into your eyepiece are fiddly and easy to drop or lose. Instead if you want to try coloured filters, try photographic filters. There are a range of square plastic filters (Cokin), with various colours you can try. These are used just in front of the eye-lens of the eyepiece, and can be easily flicked in or out of view to see what effect the filter has.

8. Averted vision

You may be able to see fainter things if you use what is called averted vision. Here you look slightly away from the object you are trying to look at and so bring more of your more light sensitive rods into play.

9. Keep looking – allow for air currents

When observing planets, spend some time viewing the object and on occasions you’ll notice momentarily you get a very sharp view when the air steadies for a short time.

10. Tap telescope

Faint objects may become clearer or more obvious if you tap your telescope or make it move slightly.

11. Expensive filters – e.g. OIII

Although the expensive filters like light pollution filters might have limited usefulness, the OIII filter is particularly recommended and will have a huge effect when trying to view objects like the Veil Nebula or the North America Nebula.

12. LARGE wheel to control focussing

A fine focus can be more easily achieved if you fit larger focus wheels to your focuser – perhaps up to 2” diameter. You can make a larger wheel just push-fit over the existing focus knob.