Beginner finder binoculars

phillean · #1 12-09-2007, 09:16 PM

Hi, a newbie here, wanting learn a bit about astronomy, look at the moon, encourage my children.

I am planning to start with good finder binoculars, maybe leading up to a reflector telescope later.

We have a community oval nearby (in Canberra) where star viewing is possible without too much urban light.

I have been reading posts and have absorbed the message about starting with binoculars in the 7 to 10x range. I was thinking of starting with 7x50 or 8x50. Is there any advantage in going to 8X56 or 9x60.

Thanks

phil

Dennis · #2 12-09-2007, 09:36 PM

Hi Phil

Welcome to IIS – it’s a great place to find out about all things astronomical.

Have you looked at the guide in the “Projects & Articles” section of IIS, Binoculars - A Basic Guide for Astronomy?

Cheers

Dennis

DJVege · #3 12-09-2007, 09:40 PM

Hi Phil. Welcome to IIS!

7x50: Magnification of 7. Lens aperture of 50mm. Exit pupil = 7.14mm.
8x50: Mag. 8. Aperture 50. Exit pupil = 6.25mm.
8x56: Mag 8. Aperture 56. Exit pupil = 7mm
9x60: Mag 9. Aperture 60. Exit pupil = 6.66mm

Ah, I'm just showing off my maths.

Really, what you want in a first set of binoculars (well, what I'd want), is the most Field of View and the most magnification and a weight that you can comfortably hold for long periods. I bought 15x70s, and let me tell you, it's difficult to hold these babies still when looking at anything in the sky. If you can, get to a shop so that you can test a few binos out...checking their weight etc...

As for where to buy...I highly recommend www.aoe.com.au. They have some literature on binos (as well as other stuff) that you'd find interesting to read and learn about. Here is the bino read -> http://www.aoe.com.au/binocular_guide.html.

Good luck!

Globular3 (Jeff) · #4 12-09-2007, 10:03 PM

Hello phillean,

Welcome. I think you're on the right track with the 7 x 50 binoculars. They will have great light grasping capacity, provide a wider field of view than higher power ones & also be easier to hold still because of the lower power (as well as probably being less weight to support). You're hand movement will be less exaggerated. Also, it should be easier for the kids to use. It would be good to consider getting fully coated optics to reduce loss from reflection and make sure that they DON'T have rubicon (reddish) coating to reduce glare. This is great for the day time but NOT for astronomy as it will reduce the brightness of objects at night. A final point to consider is being able to attach the binoculars to a simple tripod. They need to have a small screw hole at the front to do this if you want that.

Well all the best and have fun.

phillean · #5 12-09-2007, 10:06 PM

Thanks DJVERGE and Dennis

I have looked at those sources/references and they are useful, though they mean more as I read more posts.

I am likely to buy from AOE. I need to consider children (9 years to 16 years) holding the binoculars so they can't be more than 1.25kg, preferably lighter and must have long eye relief to make it easy at the beginning. It would be good if these binoculars could be used for other purposes. The AOE 8x56 seems like a good compromise at 105 FOV and 24mm eye relief.

Later I plan to get something like the AOE 20x80T (Triplet Lens) to use on my heavy tripod which has an excellent pan and tilt head.

Any comments on the AOE 8x56 ?

phil

phillean · #6 12-09-2007, 10:16 PM

Thanks Globular3

It seems to be a choice between the AOE 7x50 HR and the AOE 8x56. I am not sure which has the best light gathering ability.

The close focus of the 7x50 HR does make them useful for wildlife viewing etc.

phil

iceman (Mike) · #7 13-09-2007, 06:26 AM

Hi Phil,

to IIS!

If the kids plan on holding them, then 7x50 would be best. If it was adult, I'd say 10x50 but the extra magnification may give too much wobbling when held by children.

Starting with binoculars is a great idea. Hopefully it will get the kids hooked!

rmcpb (Rob) · #8 13-09-2007, 08:28 AM

Phil,

Welcome to IIS

I would say go for a set of 7x50s. I used an old set for years before getting my scope and they were great. If the astronomy bug grabs hold then bigger and more astronomical things will come, if not you have a useful set of field binoculars.

Cheers

janoskiss (Steve H) · #9 13-09-2007, 10:32 AM

Yep 7x50 AOE HR or WP would do very well. 7x is a lot nicer to hand hold than 10x but if you have a steady grip 10x50 lets you see a bit more (and has almost the same apparent field of view as the 7x50).

The AOE 8x56 is from the same line as the other budget ones they have, and it is not as well made as the HR and WP models - still good usable bino and good value but bit behind mechanically (eg. flex in EP bracket makes it easy to go out of focus while in use) as well as optically (eg, poor illumination near edge of field, inferior baffling for controlling stray light / reflections).

phillean · #10 13-09-2007, 10:10 PM

Thanks for your help everyone. I will be ordering a pair of 7x50 from AOE.

I am learning some software programs, Winstars 2 is running fine and I have downloaded a several others to try, based on comments in previous posts in this forum.

I also reading about telescopes and if all goes well I will buy one around Christmas, the Celeston Astromaster 130 looks good but something cheaper would be nice too.

Do you think this is a suitable first scope ?

Phil

iceman (Mike) · #11 14-09-2007, 06:05 AM

Hi Phil
What's your budget and how old are the kids? I'm not sure what the celestron astromaster 130 is, but it sounds like a little 5" reflector.

If you read any of the beginners threads the theme is always the same - an 8" dob is the best value for money scope you can get. If the kids are young, a 6" dob might be better.

rmcpb (Rob) · #12 14-09-2007, 08:28 AM

Phil,

I have 10 & 8 year old sons and they can drive the 8" dob like pros. They can't handle the 13" as well but, if its set up on level ground they will give it a run. I worry more about eyepieces bouncing off the mirror with that one rather than their ability to actually use it

Cheers

janoskiss (Steve H) · #13 14-09-2007, 01:29 PM

yep 8" dob is a fantastic scope - unbeatable value and usability. I use mine almost every day

phillean · #14 14-09-2007, 04:37 PM

Thanks Mike, Rob and Steve

My children are in the 10 to 16 years size range and $450 to 550 is about my price limit.

I Had thought of using a tripod mounted scope but I can see after more reading why the Dobsonian 8" is better for beginners - large light gathering, easy to align and access - don't have to be up at the height of the tripod.

Fortunately the community oval near us has concrete cricket pitch in the middle, a nice flat location for setting up a scope and a reasonable distance from lights - the trees in our yard block the sky and the oval is a little higher up above most nearby street lights.

It will be a while before I purchase so I have time to look around. So far the Bintel/Guan Sheng seems to be very popular and in my price range. Are there others I should consider ? I notice that AOE has the Saxon range, any comments on these?

phil

janoskiss (Steve H) · #15 14-09-2007, 05:14 PM

Saxon is only worth considering if you are after a 10" IMO. For an 8" I'd recommend the GSO. And I'd recommend you don't get tempted to up to a 10" because the 8" is a sweet spot on the compromise curve of aperture and portability/mobility.

rmcpb (Rob) · #16 14-09-2007, 07:36 PM

I agree with Steve but get the model with a Crayford focuser, even if it means that you have to save a bit longer. It will be well worth it!!

Fans, etc can be easily added later but the focuser is the best upgrade I have made to my OTA hands down.

phillean · #17 15-09-2007, 10:48 PM

Thanks Rob and Steve

I saw a rack and pinion focuser in action today and later looked up a diagram and explanation for the Crayford system and now understand how the Crayford gives better control.

I plan to share viewing with a friend who has difficulty with short eye relief lenses, I am thinking of obtaining a couple of good quality long eye relief lenses to complement those that come with most telescopes (such as the GSO). Any suggestions?

phil

erick (Eric) · #18 16-09-2007, 01:34 PM

Quote:

Originally Posted by phillean

...obtaining a couple of good quality long eye relief lenses to complement those that come with most telescopes (such as the GSO). Any suggestions?.....

I suggest the Vixen LV range for long eye relief. Do a bit of research on them - there are a number of reviews on the net. And they are mentioned on this site. I have 10mm and 6mm.

stringscope (Ian) · #19 16-09-2007, 02:07 PM

Hi Phillian,

Just in case you have not attended one of our meetings: The Canberra Astronomical Society sells 7X50 bino's at a very reasonable price. Also CAS has a large range of telescopes for hire at very low $ ..... about $5-10/month for members. We also run regular observing sessions where you can get to try out all different types of scopes and equipment which can help you work out what best suits your needs.

Next CAS meeting is this Thursday night 20/9 at Mt Stromlo, Introductory group is 1900-2000 followed by the main meeting to about 2230.

All welcome, feel free to come along.

Cheers,

rmcpb (Rob) · #20 16-09-2007, 06:52 PM

Let's not get into eyepieces before you ge the scope. Accessories are a huge black hole for money and descisions made in haste will be regretted at leisure.

If you really need long eye relief though also look at the Celestron series they are good value for money, not brilliant but good solid workers.