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Hand-held binoculars for use in light polluted city

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#1 Cheesefries0707

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Posted 08 December 2019 - 04:11 AM

Hi guys,

I am looking to get a decent entry level binoculars to accompany my 8inch Dob.

I live in Singapore which has high light pollution, I was wondering if 8x42 is sufficient ? I do not intend to use a tripod. Also, I do have mild astigmatism so sometimes I wear glasses.

My primary purpose is to stargaze and learn about the constellation. Not sure if looking for DSO is possible in my situation with a binoculars

I am thinking of either the nikon aculon or the celestron nature Dx?

What do you guys think?

Thanks!

#2 Antonio R.G

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Posted 08 December 2019 - 04:48 AM

8x42 can be ok.. but 10x50 or 12x50 will be better because more power will give more contrast image.. 12x50 will be perfect... but you don't want to use tripod.. (but in a comfortable position supporting the elbows is suitable..). Aculon has very good optic for price but eye relief is short, no ideal for eyeglasses wearers. Action EX is ok, excellent comments about this bino here..

#3 Erik Bakker

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Posted 08 December 2019 - 04:49 AM

Welcome to CN!

 

42mm of aperture is more than sufficient, though aperture fever always makes us want more aperture.

 

In a light polluted city, you want an exit pupil in the 3-4mm range, to maximize contrast of DSO's against the light polluted sky. So in the 42mm class, you will see much more with the 10x model. 

Since you mentioned you have astigmatism, you will benefit from the smallest exit pupil possible, so you can use the best part of your eyes.

 

The exit pupil can be calculate by D/M. Where D is the diameter of the binocular in mm and M is the magnification. A 10x42 has an exit pupil of 4.2mm, still a bit large

 

A 10x32 is also worth considering. My 10x32 put up some superb views of M33, M51 and M81/M82 under light polluted conditions, better than a 8x42 side by side. And at an exit pupil of 3.2mm, your astigmatism will become almost invisible AND will bring you wonderful background contrast.

 

Just buy the best quality you can comfortably afford, since that quality will have noticeable impact on the clarity, sharpness and contrast of the views. Which will be even more important in a smaller instrument when using it for low contrast deep sky objects.


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#4 Tony Flanders

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Posted 08 December 2019 - 07:00 AM

I live in Singapore which has high light pollution, I was wondering if 8x42 is sufficient ...

My primary purpose is to stargaze and learn about the constellation. Not sure if looking for DSO is possible in my situation with a binoculars


You are very astute. I am sure that you can in fact see some deep-sky objects through binoculars from Singapore -- indeed, I imagine that you can see at least one (the Pleiades) even with your unaided eyes, though perhaps not easily.

But I strongly suspect that for you, the main value of binoculars will be filling in the constellations by showing the stars that are necessary to complete the constellation patterns, but are too faint to see with your unaided eyes.

You don't need a lot of aperture for that purpose, and high magnification is actually counterproductive because it tends to reduce the true field of view. My favorite constellation-viewing binoculars are my 7x35s, but that specification is rather hard to find these days. I'm sure that something in the 8x40 range will do very well for you.



#5 PEterW

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Posted 08 December 2019 - 07:53 AM

Try to avoid local dazzling lights. Use lens shields and also winged eye cups to help your eyes get as dark adapted as they can. As suggested higher powers should help cut through the light pollution and help see stellar objects and clusters. Nebulous DSO are likely to be harder. If you can get to a place on Singapore which has the lowest light pollution you’ll have more luck... I visited last year and from the Bay Area there was pretty much nothing except the moon and jupiter visible, I wish you luck!

Peter

#6 grif 678

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Posted 08 December 2019 - 09:30 AM

I would try a nice vintage pair of the Sears 7 -15 X  35 zoom binoculars. They would be perfect, and fill both voids. I love mine, at 7 X, you have the wide field you need to be able to see more of the constellation stars in the same field of view, and as you zoom in, the back ground sky seems to get darker, so you not only see things closer, but in more contrast. I have had two pairs of these, and the vintage sears binoculars have a reputation for outstanding optics. There are always several pairs on ebay, and they range from around $35 to $50 dollars. You can look at the pictures and see how good condition they are in. Since being a zoom, these can be used in light polluted skies at the higher powers, and work great in dark skies with the lower powers. These are well built binoculars, and very light, and easy to hold.




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