Was I expecting too much?

[Sidd]

So I have used my new scope Meade Polaris 76mm for a couple of viewing sessions recently and have really enjoyed myself. However, I just nee dot ask about the following few questions really in order to satisfy myself as to whether I am doing everything all right and my scope has limitations or would more time and patience reveal more to me. 

The scope came with two eye pieces 26mm and 6.1mm and a barlow. I shall explain the experience and then ask my questions:

The first night I missed the moon, jupiter and saturn as they went towards the western part of the sky which was not visible from my balcony (6800 feet high in the mountains with clear dark skies- saying this for perspective in relation to my questions) so I went for Andromeda (yes crazy but true- the first thing I viewed with my humble 76mm was andromeda). So once I viewed it and locked it through 26mm I wanted to switch to 6.1mm and when I did that and tweaked ot find it again in 6.1mm I suddenly noticed everything was so dark in there even the stars near the galaxy went dim and dark and totally out of focus - I tried to focus but to no avail. Same results with 26mm and barlow as I could not resolve any detail on it. 

The next night I saw the moon and saturn and to tell you the truth 26mm and 6.1mm and barlow on both worked really well on these brighter objects. So the lens aren't bad but its just that viewing fainter distant objects isn't going to be easy. I also viewed the orion nebula with 26mm with ease, with 6.1mm it was kind of ok but with barrow again I think I needed time and patience. 

Finally- my question is this: Is this what I am always going to view given the humble specs of my scope 76mm/f700 or do you guys think that with a bit of experience and patience and more and more sessions like these my viewing and focusing is going to improve on the same eye pieces and I will be able to resolve the objects better ???

Looking forward ! thanks 

[dweller25]

That all sounds normal to me.

As you have found, it is better to use the 26mm for deep sky objects as they are large and diffuse.

The Moon and and planets will allow higher magnifications as they are brighter.

Enjoy your telescope.

[Nigeyboy]

As David says, this is normal. As magnification increases, the view will become progressively darker. Even in my 150mm reflector (Skywatcher 150-PL), when I crank up to x 200 and look at the moon, the image is a lot darker than when viewing at x 48. M31 and M45 won't fit in my widest field of view with the 150-PL, but most other objects will. Again, as David said these objects are best observed with a wide angle. All the other Messier objects should fit well within your field of view.

Thing to remember here is, as general rule of thumb, max magnification is around 2 x aperture in MM - so 76 x 2 = 152 x. So, with your lowest mm eyepiece of 6.1, and the Barlow you magnification would have been around x 200 - too much for your scope to handle I think. When viewing M31, let your eyes become adjusted to the dark, pop in the 26mm and spend time at the eyepiece. Its amazing what detail can jump out!

Happy viewing!

Nige

 

[Ruud]

With larger magnifications the available amount of light gets spread wider, which is why you get dimmer images. As Nige says, your telescope with its 76mm aperture maxes out at 152x (two times 76).

The planets may be a tiny disappointment, but not all is lost. By no means! With the 26mm eyepiece (at 27x) you should get great views of open and globular clusters, quite a few galaxies and other deeps space objects. And the 26mm together with the Barlow will reveal many of the smaller planetary nebulae.

Use Stellarium to get an idea of what is within your reach. Here is an example of  tonight's sky over Pakistan with 9 as limiting magnitude:

Stellarium is freeware. Get it from stellarium.org

 

[Louis D]

With each doubling in power, surface brightness is quartered (squared rule).  This isn't such a big deal for stars because they are not extended objects, so star clusters end up taking power quite well.  This is why you can really crank up the power to split tight doubles.

Since you went up roughly 4x in power going from 26mm to 6.1mm, surface brightness went down by 16x, which is quite noticeable as you discovered.  To avoid this darkening, just increase your aperture by 4x in diameter to 300mm (12 inches or 1 foot) by buying a larger telescope. 😉

[veteran neophyte]

Sidd, lest you be concerned about the quality of your equipment, I can tell you that I get the exact same results using a 3-6mm Nagler zoom eyepiece (it's a Televue product so you *know* it's good) on my 100mm Takahashi fluorite apochromat refractor (also clearly a high quality piece of equipment.)  It's just the way optics works. 

Edited September 13, 2019 by veteran neophyte
forgot a word

[Sidd]

Thanks a lot everyone for your kind responses. I am much clear about many things now...

Wishing you all clear dark skies.