INTANE OPTICS BLOG

Time: November 21,2008

Location:Yinna Mountain,Meizhou, GuangDong, China

Photographer: Wei Huang

Refractor：Intane Triplet 80mm F7 APO Refractor with Vixen 0.67x field reducer

Mount: Vixen Sphinx SXW

Camera: Canon 450D Baader IR Filter Modified, Cooling Modified

Guide: Mizar GT68(D=68mm,f=600mm)+ Vixen GA4+ Mizar Or6

Exposure: ISO800 composite of 16X8min ,4X2min,4X12sw

Processing: Deepskystacker, Photoshop CS

Weather : Clearness, Transparency fine.

Naked eye limiting magnitude: 6

m42

Most first-time telescope users know little or nothing about the night sky, and you certainly do not need a course in astronomy to enjoy your telescope to the fullest. Begin with the objects easiest to find: the Moon, Jupiter, Saturn, Venus, Mars.

All of these are bright objects even in the midst of a big-city environment and can be located by using star maps in popular monthly magazines such as Astronomy or Sky & Telescope. For more advanced celestial listings, use Meade Star Charts or Meade Epoch 2000sk sky software. With only a little study, you will quickly be star-hopping from one object to another.

Some types of objects (e.g., nebulae and galaxies) are best observed in a dark-sky environment, although even many of these are clearly observable through small telescopes in the city. The Moon and planets, by contrast, can be studied about equally well from the city or country. The basic rule is that while observations made outside the city generally reveal more detail, particularly in deep space, there are still a great many objects within the grasp of a small telescope in urban areas.

Location:Shenzhen Convention & Exhibition Center, China

Time:September 6-9,2008 Four days

Exhibition Time:September 6-9 9:00 AM - 5:00 PM

Exhibition NO.: 9439#

Exhibition Products:

• Reflective & Refractive Collimator
• Apochromatic Lenses
• High-fidelity, Short Focal Length ,Wide Angle Projection Lenses
• Laser Application Lenses
• Lenses for Digital Wavefront Measuring Interferometers
• Telescope & Accessories
• High Precision spherical & aspherical optical lenses & mirrrors.

Dear Alice,

We have finally find some time for testing the telescope today.

We test the telescopes next to the WO Megrez from Fred.

First impressions from Fred are: The telescope is looking beautiful and has a nice design (this is only the mechanical he looked at)

Then we have test it on several objects like streetlights and traffic signs and some white buildings the first impression of the optics are good.

We also have looked at the magnification of both scopes that look equal.

But we have to try it on the moon, so we get a better impression.

Well we’re working on it and when we have a clear night we will test the telescopes next to each other.

There is one thing you should no, the Megrez from Fred is handpict by WO.

So his telescope is very good.

But this is what Fred said to me about the optics of the Intane Telescope

André, it looks you have a good Apo here.

When we are testing the scope at night ( hope we have soon a clear one) then first we make a small report and then later on we can work it out for a review.

I hope that you are satisfied by this message.

Best Regards

André

SwanOptics

http://www.hkastroforum.net/viewtopic.php?t=11952

USEFUL MAGNIFICATION RANGES FOR VISUAL OBSERVING
IN ASTRONOMICAL TELESCOPES

LOW POWER (3.6 to 9.9x per inch of aperture)(7mm to 2.6mm exit pupil):
Useful for finding objects and for observing ones of large angular size like open clusters, large faint nebulae, or some larger galaxies. For lunar work in modest apertures, it is generally somewhat on the low side, but can show the crescent moon with background starfields well. This is also the range where Nebula filters tend to perform the best. Some of the wider double stars can also be best appreciated in this power range.

MEDIUM POWER (10x to 18.9x per inch of aperture)(2.5mm to 1.3mm exit pupil):
Useful for observing somewhat smaller deep-sky objects such as galaxies, some diffuse nebulae, smaller open clusters, and moderate to large planetary nebulae. Also useful in apertures 6 inches and larger for getting at least partial resolution on the brightest globular star clusters. Often used in moderate to large apertures for detecting very small galaxies which may be invisible at low powers and for revealing details in some galaxies like dark lanes, mottling, and star-like nucleii. Very useful for wide area views of the moon, or for showing the moon systems and some of the larger features of the planets.

HIGH POWER (19x to 31.9x per inch of aperture)(1.3mm to 0.8mm exit pupil): A very useful power range for observing fine planetary and lunar detail. This is the range where the full theoretical resolving power of the telescope is becoming visible. Also useful in moderate to large apertures for getting better star resolution in tight globular clusters or for viewing detail in the smaller planetary nebulae, as well as resolving tight double stars. This power range is sometimes compromised in apertures larger than 5 inches by seeing effects (ie: disturbances in the Earth’s atmosphere which can blur fine detail).

VERY HIGH POWER (32x to 46.9x per inch of aperture)(0.8mm to 0.5mm exit pupil): Useful for study of certain specific planetary details, and resolving very tight double stars near or just above the resolution limit of the instrument. Also useful in larger telescopes for resolving the cores of some very tight globular clusters or for detecting the finer detail and faint central stars in the smaller planetary nebulae. Quite useful for telescope collimation tests or rough star-testing. This power range is not as frequently usable with larger apertures due to seeing disturbances. For planetary viewing, eye defects like motes and floaters (along with the somewhat lower overall light level), begin to become visible and slightly annoying in the upper half of this range.

EXTREME POWER (47x to 75x per inch)(0.5mm to 0.3mm exit pupil). Mainly used for resolution of double stars at the resolution limit of the instrument, or for detecting elongation of unresolved doubles. Powers up to 60x per inch are sometimes usable in rather small instruments for making gross planetary detail easier for beginners to see (ie: Jupiter’s main belts or the Cassini Division in Saturn’s rings). This power range is not often used in apertures above 6 inches due to seeing limitations, and requires very good optical quality in the instrument. Even when conditions are good, lunar and planetary views using this power range can sometimes seem less pleasing overall than at somewhat lower powers due to the lower light intensity and increasing interference from eye defects like floaters. However, this range can be somewhat useful for certain *specific* targets or details which require extreme scale. Examples include (for large apertures) seeing Encke’s Division in Saturn’s rings, the central star in M57, detail in some brighter planetary nebulae, or for resolving a few small specific lunar details. Powers from 75x to 90x per inch are occasionally used for very close double star elongation, micrometer measurements, or for optical testing, but otherwise, powers well beyond 75x per inch can often be nearly useless, especially in inexpensive “department store” telescopes.

EMPTY MAGNIFICATION (100x per inch and above). Nearly useless powers, mainly used as a marketing ploy by unscrupulous telescope retailers or manufacturers to sell small over-powered telescopes to beginners.

Clear skies to you.

——————–
David W. Knisely