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Posts Made By: Jim Cantrell

October 16, 2003 12:45 PM Forum: Equipment Talk

Orion Ultrablocks

Posted By Jim Cantrell

Anyone familiar with the history of these? I have a couple of them purchased used. The 1 1/4 says "Orion Skyglow Ultrablock Japan", the 2" says "Orion Ultrablock Korea". The smaller seems a bit darker and a deeper blue when viewed flat on a white paper, the larger seems a little more transparent and appears to shade a bit toward turquoise. Anyone have any information about production history of the product line?


February 7, 2004 02:30 PM Forum: Eyepieces

Powermate 2.5

Posted By Jim Cantrell

I tried one of these for the first time today with several different plossls and a couple of Sieberts. Is it my perception, or do I lose a mm or two in eye relief? It seemed that I had to move my eye closer in order for the visible field to expand enough reach the field stop of the eyepiece.


August 6, 2005 01:59 PM Forum: Deep Sky Observing

extreme red

Posted By Jim Cantrell

Ran across the reddest star I think I've ever seen last night at around RA19 Dec 6d11 - can't get very precise with my dob. Startlingly red where most star colors I see are a bit muted.


September 16, 2005 11:27 PM Forum: Binoviewers

WO Bino Viewers

Posted By Jim Cantrell

Arrived this afternoon, tried them out in my F5 GSO dob, light path too long even with the included OCS and I couldn't bring them to focus. Anyone have any ideas short of major surgery?


October 8, 2005 01:06 AM Forum: Binoviewers

WO vs BO OCA/barlow

Posted By Jim Cantrell

During break in this evenings clouds, I compared the the Burgess OCA with the one that came with my WOBVs.

In order to get the Binoviewer to work in my F5 GSO dob I replaced the bolts in the mirror cell with longer ones in order to move the primary up the tube an extra half inch.

The WO supplied oca still requires a one inch eyepiece barrel extension in order to reach focus, measurement showed the barlow to be about 1.73 when viewing through the BV.

The BO unit allowed me to reach focus without the barrel extension, but even without the extension I measured a 2.15 increase in power.

Physically, the BO unit has a larger aperture, too many passing clouds to determine if there is a difference in brightness.

October 29, 2005 09:13 PM Forum: Binoviewers

Siebert vs WO

Posted By Jim Cantrell

I was out last night under mag 5.5 skies comparing a set of Siebert Black Knights + Sieberts 1.8 OCA with my WO BVs + the supplied 1.6 Barlow. My impression was that the SBK had a slight edge in contrast, but otherwise the views looked pretty much the same.

The Siebert self centering ep holders worked very nice - well merged images every time I inserted eyepieces. In comparison, the WO compression ring holders sometime required some tinkering to get the images merged after changing eps or adjusting diopter. On the other hand, the Siebert had no diopter adjustment and required that the ep be loosened then slid in and out to adjust for difference between eyes. A case of pick your poison there.

I had to pull the Sieberts out of the focuser a little bit to get to focus - a result of having moved my primary up the tube in order to get enough infocus for my WO BVs. The Siebert BK with OCA will work in a newt with no modification.


December 30, 2003 08:51 AM Forum: Equipment Talk

i messed up badly...

Posted By Jim Cantrell

Rubbing alcohol commonly available off the shelf in stores contains glycerin or similar oils to make it's easier on the skin.

October 8, 2004 10:12 PM Forum: Eyepieces

Augen E.P's ???

Posted By Jim Cantrell

They must not have a very big customer base, John.

November 9, 2004 07:50 PM Forum: Deep Sky Observing

Triangulum Galaxy (M33)

Posted By Jim Cantrell

I have a 10"dob and mag 4 skies overhead - M33 wasn't hard to find, just hard to recognize - looked right through it many times before learning to see it, found that moving the scope a wee bit helped a lot and I could discern some shape to the glow.

UMaj is moving into favorable viewing position for me now, M51 and 81/82 are favorite targets and show well even through my urban sky, whereas M101 is just rumor...

Jim Cantrell

November 16, 2004 09:04 PM Forum: Eyepieces

Field Stop info

Posted By Jim Cantrell

According to Thierry Lombry's Eyepiece Spreadsheet, the Meade is 28.6 and the Konig is 25.1.