Personal Blog

Couple of months ago i got the idea of observing the sun using a solar filter. I ordered a cheap solar filter from Israel and  placed it front of the telescope. Note that you have to adjust the filter in front of the the telescope not between the body and the eyepiece because high temperature can be developed inside the telescope's tube. The next step was to point to the sun. Compared with the night sky it is really hard to target the sun, as you can't look (or you shouldn't) directly to the sun. The easiest trick is to align the body of the telescope with the sun to minimize the shadow created as shown in the next two pictures: Aligning the telescope to the sun using its shadow. Finally, we align as perfect we can the telescope. I aligned the telescope without the eyepiece because it was easiest to move it. The final result, note the sunspot on the right. Not perfect aligned and not the best quality, but for the 20$ price tag of the sun filter is ...

The Celestron Travel Scope 70 is a compact and cheap 70mm refractor telescope focused on portability. I ordered this telescope for two reasons: 1) i don't have telescope in my new home and i wanted something small and inexpensive. 2) All the reviews (look here and here ) are commenting on good price/quality ration. After sometime i decided to order it from Amazon. The only bad thing when ordering from Amazon is the arbitrary time of package arriving. Unfortunately, this time Amazon used the iparcel company for the transfer that caused an extra delay of 10 days. The package The package of the Celestron travel scope. Eyepieces and barlow lens of the travel scope. The package includes a telescope tube with a focal length of 400mm and aperture of 70mm, providing a focal ratio of f/5.7. The telescope uses mostly plastic components to keep the cost and weight down, including a plastic focuser and plastic lens shade. The glass lenses seems good quality and provide beau...

When someone buys a new telescope his first question is what i can see with it. The second is what is the highest zoom i can achieve. Although the maximum zoom can be an attractive measurement when buying a new telescope, the buyer should focus on the aperture size: how much light i can gather? This is the main difference from theoretical to practical highest zoom. So, what can you expect to see with this telescope? During the tests i did, the average seeing conditions with medium-low light pollution. These two factors can really improve your experience or.. to destroy it. In my place i would categorize the light pollution in class 5, based on Bortle 's scale . I also tried to improve the lenses by blackening the edges, as i described in earlier post . A quick note here before discussing my personal views on the topic. Planets and stars have different brightness that we call it apparent magnitude . Lower the number is, brighter the stellar object is. The practical limit of...

Recently i was looking to buy a second smaller telescope, ideal for traveling. I concluded on Celestrron Travel scope 70 that has the best value for money. During my research about the quality and the characteristics of the scope, i  came up to a page that was commenting how to improve the quality of the scope . Here are some thoughts about my scope: - The quality of the tube is slightly better, but still it has some issues. - You also have some bolts inside the tube, but not  many as the travelscope. - Collimation is an issue also here. You should use a collimator to fix this. However, in my case i wanted to avoid buying anything new. - Lenses are not blackened (neither in eyepieces) Collimation without tools: Collimation is usually not an important issue in refractor telescopes compared with the reflector, but it can improve the views and the experience of star gazing. You have to disassemble the telescope without caution. Take care the lenses! The easie...

Celestron 70AZ Astromaster .  This post is dedicated to one of my hobbies: astronomy. When i was little kid i was getting inspired from the stars, the planets, and space in general. Later i found my self reading late in night about light speed and time paradoxes. So, last year i said, ok why not looking at the stars using telescopes? Telescopes are not so expensive (small ones) and there is plenty of information on the net to start playing with them. I decided to go with a Celestron 70AZ Astromaster . I selected refractor because it has less maintenance compared with the reflectror (in reflector telescopes, everything must be aligned properly and the mirror loses its reflectiveness by time). After using the telescope for a couple of nights i realized that i should have selected the eq version, as it has better tripod. Moreover, sometimes i 'm missing... light: the telescope is very small for deep space objects, such as nebulas or nearby galaxies. The 90eq was more prop...