Binocular recommendation for astronomy, hand-hold and anti-dew?

[mbaddah]

I currently own a pair of AOE 7x50 and Orion Mini Giant 8x56 binoculars. I love the Orion bino's but have a problem with dew forming on the optics in dewwy condition (the AOE's are nitrogen purged and haven't experienced any dew yet).

I would love to hear people's recommendation for a pair of binoculars for astronomy which can be hand-held (enough magnification not to be shaky), offer enough aperture for bino satisfaction (50mm+) and go through the night without dew forming? Comments appreciated, thanks :)

[mbaddah]

I have my eye on the following:

- 9 x 63 Celestron Ultima
- 8 x 56 Celestron Ultima
- 10 x 50 Pentax PFC WP II

I'm leaning towards the 9 x 63 Celstron Ultima's because of it's 63mm lens. I'm just a little concerned about hand holding binos at 9x magnification.

Can anyone comment on their experience with one of the above three? Cheers.

[chris lewis]

Does the dewing occour internally as well as externally ? Dewing occours when moving from a warm envoironment to a cooler one - usually fairly suddenly. The dewing mainly occours on the outside lens. This will still happen whether they are W.P. / nitrogen purged or not. Binoculars that are W.P will stop internal fogging and long term deterioration from midew / dust spots. My top end W.P. Leicas and Minox's still have dew form on the outside lens esp. when I move from a A.C room to the warm / humid oudoors- it can take 30 mins for the external fogging / dew to go. I sometimes have to acclimatise the binos. first by leaving them outside for 30 mins or so. Both the binos you have are good astro. binoculars. They both have a 7mm exit pupil which is best on very dark skies / and or with 'young' eyes - older eyes ie. 40 + usually cannot dilate to 7 mm which can mean wasted aperture. The other 3 binos you have nominated are aslo good quality binoculars again with 7mm exit pupils - only the 10x50 Pentax has a 5 mm exit pupil. All the binos you have nominated have a relatively narrow FOV. The Celestron 9x63 will let you 'see' more but only incrementally really then your 8x56's. You need to got to a 70 mm aperture bino really to notice the difference. Most can hand hold 10x and 12x really is the maximum for free hand holding. If you do go larger ie. 15x70 you will noticably 'see' more, but will need to tripod them to maximise there abilities. The Celestron 9x63 is a good choice but honestly you will only see marginally more then your existing 8x56's and it will still fog externally.

Chris

[mbaddah]

Hi Chris,

The problem doesn't occur when bino-viewing from my backyard. It happens when I go to one of our dark sites. 20minutes and the outside of the lens is all fogged up :( The AOE 7x50 which are nitrogen purged don't seem to fog up so easily.

So your suggesting I stick with my current binos and not worry about purchasing new ones? Are there dew heaters for binos?

[chris lewis]

If you are staying free hand holding then really the binos you have are suitable. However they are both close in terms of aperture and magnification - but the 7x50 does give you a wider FOV at around 7 degrees Tfov. which is good for wide angle scanning. The Orion is narrower at 5.8 degress.
One option could be to sell the Orion and get something like a AOE 11x70 -which is still hand holdable but will enable you to noticably gather more light and see deeper. AOE and others do also sell a high quality 10.5x70 'Ultra' WP version which has excellent optical and build qualities but it is heavy.
A 70 mm size bino on a dark sky site will give you impressive viewing.
A 7x50 and a 11x70 would be a good combo.
Dew heater strips are available - try AOE or Bintel.
Mine is but one opinion - ask around and see what others say.

Chris

[dannat]

I agree with Chris, you are going to gain very little with either the ultima or pentax .

Probably the easiest thing to do rather than dew heating is to make some dew shields from poly pipe which is painted black & or flocked.{a 3-4 inches}.you just have to find some pipe which is close to the outer diameter of the binos..line the end of the pipe with black felt or velcro to help it hold

If you are not worried about the coatings - on the cheapest pair of your two binos you could apply a coating of anti-fog (sold by auto retailers) - i did it on a real cheap pair once & it helped stop dew forming. (WARNING IT COULD DAMAGE THE COATINGS) - for

[mbaddah]

Hi Chris,

I checked the weight of the 11x70 aoe binos and they seem quite heavy for hand holding unfortunately. I may just keep the Orion binos and go for something with a little more aperture and mag. I've been reading reviews of the Celstron 15x70 which seem to get a good rep for 'bang-for-buck'.

Ofcourse these will need to be mounted on a tripod of some sort.



Thanks Dannat I'll have to do something like this and test it out.

[chris lewis]

The 15x70 size is an excellent astro size binocular. With the Celestron Skymasters - they do have 'mixed' opinions and reviews. This is mainly related to the Q. and A. which can vary with them. [Read the 'Cloudy Nights' reviews]. I have had 3x over the years - 2x were miscollimtated - 1x badly with severe 'cats eyes'. The final one was good. Make sure you do get a excellent example - one that is well collimated from a company with a good return policy. Only buy one from a reputable astro optical shop. If you cannot view it yourself ask the optical sales person to check its Q. and A. prior to shipment. A tripod will maximes its potential.

Good luck

Chris

[mbaddah]

Hi Chris,

Thank you again for your informative posts. Well the more I read the more I'm discovering other fantastic binos out there :) Some include the 7x50 Fujinon WP-XL, MB-Ultra 15x70 (I'm little turned off the Celestron after reading about there QC issues), etc... Looks like I'm going to have to do some more reading before taking the plunge.

I currently own a 190XDB Manfrotta tripod with a 486RC2 head. Even at it's maximum height, I find it's a little too short for my height (I'm 173cm tall). Testing with my mini giants, the binos sit at perfect eye level when they are horizontal, but I have to crouch and bend my knees a little the moment I tilt the binos to look up. Which tripod/head combo do you recommend for 15x70? I'm using a standard bino to tripod adapter, perhaps I can get one thats a little taller rather than purchasing a new tripod/head?

Greatly appreciate the advice.

[chris lewis]

173cm / 5'8 is not short ! [Thats too close to my 176cm / 5'9" ] :lol:
The below Chinese generic tripod mount as sold by AOE and others is suitable for binos up to 80mm. For a 70mm it would be excellent. [ It says 100mm in the advertising but for a 100 mm binos you would need a heavier mount].
It reaches to 187 cm - which is about 6'2" which means you can get 'under it' to observe closer to te zenith.
With the binos - I strongly recommend saving more and buying a quality product. I have wasted thousands of dollars buying inferior optical products only to sell them and loose money. Do it right the first time. The Fujinon and Ultra range are high quality products that will give you a life time of rewarding viewing.


http://www.aoe.com.au/mounts.html

Chris

[dannat]

mbaddah & chris..aoe are no longer in business..the 190 tripod will be ok to hold the binos (i used one before) but you may want to upgrade the head..fluid is easiest like a 501 or even 700 may be OK..andrews sell a series 3000 tripod & head, which is the same as garret optical series 3000 (check the US website which has pics)..they are quite sturdy & will handle an 80mm scope easily, even small 100mm binos

i also agree 10x what chris says about quality/decent gear..it doesn't mean you have to sped squillons - the ultras i have (10x50) & had 15x70 are terrific for the price ( i now have 16x70 fujinon's).
I have celestron regals - their top of the line bino, and they are excellent, but some of their items leaves a bit to be desired - i have looked thru some disappointing glass

[chris lewis]

Daniel. Thanks - I did not know AOE had finish. I live in Kiwiland but make trips to Oz. about 2x a year.

Chris

[mbaddah]

Doh I realise I made a mistake when converting my height from feet/inches to cm I'm actually 180cm (5'11") :P

Entirely agree about getting it done right the first time, hence why I'm getting an SDM dob built after 2 gso's :) I'll be a bit more cautious with the bino purchase.



Thanks Dannat will look into the tripod heads and ultra binos you mention.