Posts Made By: Michael Mandall

Hello Group,

This is my first posting, I have a pair of nesting Coopers Hawks in the local of my home in Tucson. Hard to get close except when the female feeds on a power pole behind the house. This shot was at dusk on a grey day. Photo has been enhanced in PS to bring up contrast and brighten. I will hopefully have more pictures in the coming weeks. Your comments would be appreciated.

Equip used was a Canon EOS 1 DS mark II using a 100-400 zoom with a 2x teleconverter set at 800mm

I recently purchased an Astro-Physics 180EDT f9 scope and noticed that the lens is somewhat loose in the cell. I have a few other AP scopes have not noticed this issue. At least not to the same degree.

I have talked with other owners and this seems to be a common situation but I would like to understand just how loose the lens should be.

I have another worry relating to this issue and that concerns vibration during transportation. I would think that a loose lens would suffer to some degree from the slight vibrations its subject to during transport.

Can anyone enlighten me.

Just added a beautiful Televue MPT to my collection. Was wondering if anyone had any information on this early scope beyond what little is mentioned on the TV website and the one article I found on televues development which shows one picture of the scope.

Thanks,

Mike Mandall

I recently purchased a Zeiss APQ 100/1000 which I noticed had a small air bubble in the front element. I have never seen an air bubble in any Zeiss product I have owned and became suspect of the scopes heritage so I email'd Baader with several photos along with a general discussion and a copy of the Zygo output. The response follows. My question to the group is: Has anyone else noticed a bubble in any Zeiss telescope.

The scope actually does perform very well and the bubble apparently does no harm to the views but I am still wondering if this was something that Zeiss would have preferred to not release but did in this circumstance

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"This looks genuine in every respect."

"ESPECIALLY the bubble is a clear proof that the lens is genuine Zeiss."

"Zeiss was using extremely homogenous glass for the outer elements - and the higher the homogeneity, the higher is the likeliness to have bubbles in the glass, because Schott had been ordered for these substrates to avoid to stirr the melt too hard and to rather leave the bubbles in the melt than trying to remove the bubbles - but create striae instead."
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Thanks for any information you may have.

Mike Mandall

Bill,

I have reworked several AP focusers for the same problem. Old grease can be part of the cause however, I have found the main problem is the relationship of the rack to the pinion gear. The focuser has 4 screws which include a spacer and a spring for allowing some movement between the pinion and the rack. Any loosness in the focuser which allows the pinion to change its relationship to the rack such that the mesh angle of the gears is no longer perfectly perpendicular, causes binding. Clamping the screws down tight will cause the focuser to jam.

The best solution I have found is to shim the focuser pinion out from the rack using thin plastic or paper shims placed between each set of screws, on each side of the focuser. Shim both sides evenly and tighten down the screws carefully, adding shims until the focuser screws can be snugged down and the focuser moves freely. I have gotten good results doing this especially on my Stowaways.

I would also completely remove all of the old grease and replace it with a small amount of non-outgassing optical grease.

Clear Skys,

Mike Mandall

Just the idea that I could order an optical device from AP left me stunned. 8O I called to order one and wound up ordering one of each.

I'll post my feelings once they arrive. Should be by mid week. I know there made by someone else, but still... I think I saw snow this morning in Phoenix.

Judson,

If you want more details on the 3M tape, you can go to there website and look under "VHB (Very High Bond) Adhesive tape". They make a slew of versions in many widths and thicknesses. If there is a 3M distributor nearby you can call them up and request a sample. They make samples available to potential users free, or at least they have up until recently.

Regards,

Mike Mandall

Hands down the one set of EP's I haul around are Zeiss Abbe Orthos. They are out of production but can still be had. They are very expensive but once you use them your hooked.

I also use some of the early TV Naglers, Radians and Takahashi LE's which are all fine planetaery EP's

Regards,

Mike Mandall

William Paolini said:

Would like to know everyone's recommendation for what they have experience with and consider to be the absolute best performing high power eyepiece (10mm or shorter fl). Price is to be no object in the equation and the EP must still be in production. If you want to also recommend an out-of-production unit, that's fine but please don't forget your in-production selection. If you can give a short list of what it's better than, that would be great too

Would potentially like to add one very very best available EP to the stall. Planets and Lunar is where most of it's time will be spent.

Thx!

One more photo

I heard he has.

Regards,

Mike Mandall