Simply divide your telescope’s focal length by your eyepiece focal length to get your magnification. Therefore, a 10mm is twice as powerful as a 20mm.
Is a 20mm eyepiece good?
A 20 mm is useful just as a 13 mm is useful in most any telescope but I’m not sure “all purpose” is a good description. My telescopes range in focal length from under 400 mm to about 2800mm, a 20mm is not a planetary or high power or even mid-power eyepiece in any of them, it’s a low to mid power deep sky eyepiece.
Is 10mm or 25mm better for telescope?
10mm gives you a middle-range magnification for going into more detail. For example, in a telescope with a 750mm focal length, 75X magnification. Or in a telescope with a 1000mm focal length, 100X magnification. So you’ve visited the Moon using the 25mm eyepiece, and seen the alternating dark and light areas.
What is a 10mm telescope lens good for?
10mm – 13.9mm Telescope Eyepieces: These are fine to use across all focal lengths and offer great background darkening capabilities for studying planetary nebula, small galaxies, planetary details and lunar details.
What is a 20mm lens good for telescope?
All telescopes have a fixed focal length, just like lenses on a camera. So a 20mm focal length will give you a wider field of view than say a 300mm. You will also notice that with a 300mm you get a larger image of the subject, be it a person or animal or even the moon.
Is 10mm or 20mm eyepiece better?
This means that a smaller number on an eyepiece gives a higher magnification. A 10mm eyepiece would provide twice as much magnification as a 20mm eyepiece. It also means that the same eyepiece gives different magnifications on different scopes.
Is 20mm or 10mm stronger?
Simply divide your telescope’s focal length by your eyepiece focal length to get your magnification. Therefore, a 10mm is twice as powerful as a 20mm.
What magnification do you need to see planets?
Experienced planetary observers use 20x to 30x per inch of aperture to see the most planetary detail. Double-star observers go higher, up to 50x per inch (which corresponds to a ½-mm exit pupil). Beyond this, telescope magnification power and eye limitations degrade the view.
What magnification do you need to see Jupiter’s Red Spot?
Although you can see the Spot in a 4-inch telescope, a 6-inch telescope will probably be required for his project as you’ll need a magnification of 200x or more.
Which eyepiece is best for viewing planets?
The focal length of the telescope is 900mm, so to achieve the maximum useful magnification, then a 4.5mm eyepiece would be ideal. One of the best parts about planetary viewing or imaging is that since the objects are so bright, you can do it just about anywhere regardless of light pollution.
Is higher mm better for telescope?
Apertures commonly recommended for beginner telescopes range anywhere from 2.8 inches (70 mm) up to 10 inches. In general, the larger a telescope’s aperture, the more impressive any given object will look.
What size telescope eyepiece do I need?
The largest-focal-length eyepiece you can use with your telescope is easy to calculate: multiply the focal ratio (the focal length of your scope divided by its aperture) by 7. For example, your Newtonian scope is f/5: the largest-focal-length eyepiece you should use is 35 mm.
Is a 20mm telescope good?
A 20 mm is useful just as a 13 mm is useful in most any telescope but I’m not sure “all purpose” is a good description. My telescopes range in focal length from under 400 mm to about 2800mm, a 20mm is not a planetary or high power or even mid-power eyepiece in any of them, it’s a low to mid power deep sky eyepiece.
What magnification is good for a telescope?
For most purposes, a telescope’s maximum useful magnification is 50 times its aperture in inches (or twice its aperture in millimeters) . So you’d need a 12-inch-wide scope to get a decent image at 600×. And even then, you’d need to wait for a night when the observing conditions are perfect.
What lens do I need to see Venus?
Tip #3: The best equipment for viewing Venus
Use a telescope of at least 60mm (2.4”) aperture or greater with at least 50x magnification to observe the planet and note any changes over time.
Whats stronger 10mm or 25mm?
The larger one is normally between 20mm and 25mm and is the lower power (lowest magnification). The smaller (higher magnification) is normally around 10mm.The eyepiece with the longer focal length say 25mm (low power) used on a telescope with a 1000mm focal length will produce a magnification of 1000 ÷ 25 = 40x.
What focal length eyepiece do you need?
Usually, you’ll want to start with low power (i.e., long eyepiece focal length, such as 25 mm or 30 mm) to get the object in the field of view of the telescope. Then you might want to try a slightly higher-power (shorter focal length, maybe 18 mm or 15 mm) eyepiece and see if the view looks any better.
What does a Barlow lens do?
A Barlow lens is an optical tube containing lens elements that diverge the light passing through them. Named after English physicist and mathematician Peter Barlow, Barlow lenses add a second lot of magnification to each of your eyepieces while maintaining the existing eye relief.
What is a 20mm eyepiece?
20mm telescope eyepiece excels at low power scanning of open star clusters and viewing of nebulas and larger galaxies. Offers a 52-deg apparent field of view for clear, sharp images of impressively high contrast. Multi-coated for excellent light transmission and bright, clear views.
What do different telescope eyepieces do?
Buying a telescope eyepiece. Your choice of eyepiece will determine the magnification and the size of the field of view that your telescope will deliver.
Can you see Jupiter with a telescope?
Jupiter is the celestial object with the most observable detail similar to the Sun and Moon. You can see Jupiter with any size telescope. Even small scopes can provide observable detail, such as its dark stripes (the North and South Equatorial Belts).
Contents