Front Surface Mirror for bino mount....

[JohnH]

I was thinking to make a mirror based mount for my newly acquired 15*70 binos (thanks yagon !) and came across this :

http://cgi.ebay.com.au/Stage-Laser-Light-Bounce-Front-Surface-Mirror-Frame-8_W0QQitemZ110049369535QQihZ001QQca tegoryZ15257QQrdZ1QQcmdZViewItem


on ebay - seems to be about 90% of what I need to make it work...has any fellow IISer made one of these mounts - and if so where was the mirror sourced from AU or overseas?

What are the issues with this type of mount vs a p-mount?

[Satchmo]

Just a warning there John, these mirrors might be just aluminised window glass. At 15 X you'll definately need optically polished glass to be flat enough not to distort your star images. I've allready been down that route :) It doesn't need to be any particular wave rating or anything, just ground and polished any old how will smooth th eusual float glass enough for low power optical purposes.

I'm not sure of a an off the shelf source of such glass. perhaps search on Cloudy Nights Forum for sources.

This commercial unit from Oberwerk in the USA, uses optically polished mirrors and would be well worth the cost at $170 USD. Remember of course the view is reversed which has put me off pursuing it any further.

http://www.bigbinoculars.com/mirror.htm

A paralleogram mount makes the best sense I think if you want a natural view.

[erick]

Plus the mirror will probably attract every drop of dew in the area and it would be difficult to shield?? Might have to be heated?

[seeker372011]

I built myself a mirror mount using an FS mirror from

http://www.fsmirrors.com/

I found it great for smaller binos-upto my 11 x 60s -but not so great for my 20 x 80s

dewing is an issue, as is the issue of it being harder to find stuff because of the image reversal issue

personally I find it very pleasant to sit and observe with a mirror mount -but in the end it comes down to personal preference-its a holden vs ford comparison-when you compare to a parrallelogram mount

[Satchmo]

Ineteresting. Did you use the Standard or Premium glass they list. I note even the Premium they say is good to X18. I note however that this is still float glass and not optically polished.

[JohnH]

Thanks for the valuable feedback guys - I think I will proceed with the mirror method - the p-mount is more costly/less portable/longer to setup. I do think I will mind the sky being reversed as much as I mind the neck strain...so I guess it now comes down to buy or build...the oberwork unit looks neat. Thinking....

PS I read that you can salvage a front surface mirror from an old laser printer or photocopier - but I do not know if the mirrors would be large enough or, for that matter, where I would go to find old office equipment in Sydney.

[JohnH]

PS - off topic - another way to read Standard or Premium glass - ASW19 or ASH25 ?

Satchmo - where/what do you fly mate? Sky looks blue in your image - but the grin is large - winter thermals?

[Glenhuon]

I have a few of these here from old photocopiers, scanners and laser printers, excellent mirrors but they are pretty narrow, only about 12 to 20mm wide. Never thought about using them for a Bino mount, might give it a try if we get a clear sky before summer :) I have some sheets of glass from flatbed scanners too which should be pretty flat.

Glenhuon, collector of lenses, mirrors and other things optical.

[CoombellKid]

I have seen and used such a bino setup using front surface mirror from an old
photocopier. and although I dont recall the exact dimensions or which
particular model photocopier it came from. It was certainly allot wider than
12-20 mm. Easily suitable for a pair of say 10x50 bino's.

regards,CS

[Glenhuon]

Just had a look in the bag of mirrors and you are right Coombelkid, theres a couple of 40 x 200 ones from a photocopier hiding down the bottom. Would be ideal. Another project to add to the list.

[seeker372011]

the cheapest alternative-in case you dont have a photo copier handy to cannibalise, would be to go to Surplus Shed. They often have FS mirrors at very cheap prices-worth checking often as new stuff comes up all the time

http://www.surplusshed.com/
they dont mind small orders and will even ship by sea to keep cost down always found service excellent

[Satchmo]

Hehe... The lift has been non existant the last few months. I fly at Mangrove Mountain, and nothing so exotic as an ASH25 I'm afraid just Astir CS /PW5/Pilatus/Puchatek and venerable Blanik. I'm looking forward to our annual ridge soaring camp at Gloucester in 3 weeks. How about you John are you a current glider pilot?

[JohnH]

Wife and I are lapsed pilots both - with intentions to return to it when the familiy is a bit older - we flew at Lake Keepit for a few years but mostly of our flying was in the UK and France before we emigrated. Mangrove Mountain is the closest club to where we live we should visit again in the summer.

[Satchmo]

Its closest for me too ( living in Berowra ). Come for a fly with me sometime :) . We often get to 7500ft legal ceiling in Summer. And I always find the winch launch pretty exhilerating too.