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Editorial Note:  With a partial solar eclipse being visible in select parts of North America today it is a good time to re-cap one of our older posts about how to project and image of the sun onto cardboard using a telescope or binoculars. Sadly given that we are still in a Nor’Easter here in the Philadelphia region we will probably not be able to enjoy the eclipse.  So be sure to view it for us if you are able:

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With the just passed annular eclipse out in the Western part of the USA a couple of weekends ago and the upcoming transition of Venus you might be inclined to buy  a fancy solar filter for that telescope.

Well there might be a problem with that. See everyone else had the same idea as you, and that means the manufacturers of such filters are pretty much out of stock! It can even be hard to find just the filter material! What to do?

Well, there is another way of viewing the sun without the use of a filter. It can be tricky and it can be dangerous if proper care is not taken.  That method is called projection astronomy. This is where you use the telescope & eyepiece to actually project the image you would normally see with your eye onto a board or other bright surface.

What do you need? You need a telescope with an eyepiece (preferably lower-medium powered), a sunny day, and something to project the image onto.

We came up with this kind of last minute, so we just used a flat box on a clipboard. It had problems with the box seams, but the surface was very bright (brighter than the average piece of printer paper) and so would give a decent image.

Crude, but effective.

Next up, we need a telescope. We used an Orion StarBlast 6 , mostly because that is what we had around the store.

Telescope is in action.

Note that the picture above shows the telescope in action. When setting it up and aiming it you should LEAVE THE DUST COVER ON.  This is the best thing for your safety.

Aiming your telescope at the sun is pretty easy, just try to get your tube to make the smallest shadow possible.  When you think you are on target, remove the dust cover and see if there is any light coming through the eyepiece. DO NOT look into the eyepiece, ALSO DO NOT LOOK DOWN THE AT THE EYEPIECE. View it from the side. We are not responsible for your losing your eyesight!!!

Now a further  safety warning: Try to avoid getting any body parts in the path of the light coming out of the eyepiece. Hold the board on the edge, work around the telescope, not over it, etc.

So now that you are lined up with the sun, you can see what kind of image you have. Place the projection board about a foot or so away from the eyepiece. Move it closer or further away to try and get it into focus. DO NOT bring it closer than 6 inches from the eyepiece, the light is a little too concentrated there and some types of paper might burn.

Some adjusting will be needed. It is best to move the screen rather than the telescope. If you must adjust the focuser, put the dust cover over the front of the telescope.

So what kind of view so you get? Well, here is a shot of the screen that is a little closer than the last photo:

This didn’t show up too well in the photo, but if you look closely, you can see some sunspots projected on to the board to the right and right/down of the center.

 

How well will projection astronomy work on the transit of Venus? We don’t know for certain. The sun will be very low in the sky and there may be more distortion or discoloration as a result. But if you have the time and the telescope, this isn’t exactly an expensive experiment! Just remember to be careful! Pointing a telescope at the sun always has risks – just use common sense and keep out of the path of the projected sunlight and you should  be fine!

www.spectrum-scientifics.com

 

So we’ve carried little indoor helicopter toys, such as this Mini-Flyer Soccer Ball. They are great fun at a low price. But now the same company that makes the Mini-Flyers has added the new Sky Runner, an indoor/outdoor quadracopter.

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So in our previous entry we talked about what not to do when cleaning sensitive optics such as telescope lenses and binoculars. Now it is time for a better explanation of how to properly clean those optical lenses. Note that everything mentioned here can be applied to binocular lenses, telescope lenses, and even camera lenses.

Before we discuss specific cleaning methods let me state the first rule of lens cleaning, similar to Hypocratic Oath:

DO NO HARM!

If your lenses are not dirty, don’t clean them for the sake of cleaning them.  If a tiny smudge is on your lens but isn’t showing any effect on viewing, just let it be. All too many lenses have been damaged or destroyed by unneeded cleaning.  So consider carefully before starting the cleaning process.

We are going to discuss two methods of cleaning optics: using a cleaner and lens tissue and using a Lens Cleaning Pen. Let’s start with the latter.

Method 1: Lens Cleaning Pen

Lens cleaning pens are sold under a variety of names but they mostly have the same features: A soft dusting brush and a flat cleaning end. The first thing you will do is brush the lens gently with the brush end.

Lenscleaning1

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So say you have a nice pair of binoculars or a good refracting telescope (or spotting scope). One day you are about to use it and you discover some kind of smear 102on the front lens.  Perhaps it was a droplet of water from the day you were viewing and a small rainstorm brewed up? Doesn’t matter, you need to clean that lens or otherwise your view will be very diminished. So you grab a tissue from the bathroom and some window cleaner and….

STOP

OK, let’s talk about glass and the things we put on it to see better. Glass is a fairly hard material but it can be scratched, but a greater concern for your nice binoculars is the coatings on the lenses. You might notice that purple/green/blue coloring in the reflection if you look at the lenses at an angle. These coating are very important to the binocular/telescope’s optical quality and you cannot just use anything to clean them.

Why?

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More fun products came through our doors today at Spectrum Scientifics. The most notable was the new inflatable dinosaurs! Starting with the King itself, the Inflatable T-Rex!

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Rawr!

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So after showing the Metal Earth 1965 Ford Mustang, the Tiger Moth Biplane and the Stag Beetle on Thursday it is now time for the remaining new Metal Erth Models. The first up is the Metal Earth Drum Set

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Metal Earth Models are great little models you build from laser-cut sheets of steel! We’ve been selling them for several years and now have added a few more great entries from the product line.  Let’s look at 3 of the new ones. We’ll start with the Ford 1965 Mustang Coupe!

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