All at sea without goggles

This column has already written about the need to avoid white light while you are observing so that you can preserve your ability to view faint objects in the sky. Once lost, this so-called dark adaption can take several minutes to return as your shrunken pupils expand fully once more to soak in those photons that have spent such a long time beaming their way across the universe to your eyeball. So what to do when you're out there at the telescope and you suddenly realise you've left something vital indoors such as an eyepiece, star chart or cup of coffee? If you've family in there living a normal life, you can't just turn off all the lights. Neither is it safe to walk around with your eyes closed. Thanks therefore to Brian Livesey, from Lancashire, for reminding the SPA Forum of a handy tip suggested by J B Sidgwick in his classic guide Observational Astronomy For Amateurs. Buy a pair of swimming goggles from a sports shop and replace or cover the glass with red cellophane. That should help you to see your way, save your sight . . . and probably give the family a good laugh into the bargain. Category: Intermediate.

Would dew believe it?

Autumn in temperate climes brings one of the amateur astronomer's big problems - dew. As the temperature of telescopes drops, water vapour condenses on the glass surfaces making observing very difficult. Dew shields can delay its formation and you can buy special battery-powered tapes for many telescopes to help prevent it forming but they tend to be expensive. One way round the problem is to take your telescope into a warm room for a while, if possible, and pop your eyepieces into a warm pocket between uses to keep them dry. But another tip to to buy a portable hairdryer that will run from a 12 volt battery. A quick blast from time to time will be enough to warm your optics and clear the dew, allowing you to carry on observing. Category: Intermediate

See the light when observing

You might want to shine a light while you're observing - perhaps to adjust your telescope or check a star chart. But the wrong sort of light can dramatically affect your observing. A normal white torch will be so dazzling that your eyes have no chance of observing faint objects. The answer is to use red light. This allows you to see while having no effect on your eyes' sensitivity to the sky - what astronomers call your dark adaption. Avoiding white light is especially important if you are observing with others - at a star party, for example. Blinding others with white light will not do a lot for your popularity. Category: Beginners

Research that telescope

It is virtually impossible to judge the quality of a telescope just by looking at it. It might have a colourful or shiny tube, but that will tell you nothing about those vital optics. As a general rule, avoid anything in newspaper adverts - they are usually accompanied by exagerated claims for their magnification. The best way to check out a telescope is to find out what others say about it. Use a search engine like Google to look up the make. Be exact as the manufacturer could produce a range of models which might have varying attributes. You will find reviews on a number of websites, for example Cloudynights.com But if you have a local astronomical society near you, so much the better. You will find their members have a range of telescopes and will be able to advise you about them. Best of all, you might even get the chance to look through some of them and find for yourself what they are like. Category: Beginners

Here's your safety net

When you're fumbling around with your telescope at night, it is easy to drop something. If it is something small like a screw, it can be almost impossible to find, especially in the dark! Even more difficult in the long grass. You can help avoid the problem by laying down a groundsheet before you start observing. You can buy simple plastic tarpaulins very cheaply at bargain stores. Just lay one out beneath your telescope tripod and it will make finding anything you drop a lot easier. Category: Basic

Keep your tripod stable

When you are using a telescope, it is just as important to have a stable mounting as it is to have good optics. Otherwise any vibrations will be magnified just as much as whatever you happen to be looking at. If you are stuck with a lightweight tripod, you may be able to improve the situation dramatically by hanging a heavy weight from the mount between its legs. You don't even have to take the weight with you. Fill a bag with small rocks and stones or use a bottle of water to achieve the same effect. Other observers have laid a bag of sand across the tripod's accessory tray between the legs to get a similar result. One I know even used the sand to fill the tripod's aluminium legs - just watch out for leaks! Category: Basic