You know you are there when you start thinking in terms of EXIT PUPIL rather than Magnification..
Rob Astronomy compels the soul to look upwards and leads us from this world to another..... Plato
Orion XT8i Meade 4000 plossl 6.4, 9.7, 12.4mm
Meade 4000 QX 2" 36mm
Orion Stratus 21mm, 13mm
Orion 13% moon filter
TMB planetary 9mm, 7mm, 5mm, 4mm, 3.2mm
Pentax PCF WP II 10X50 with a home made parallelogram mount
Quote:I find that grabbing the tube isn't the best method.
Orion XT8i Dob
9x50 RACI Finder TELRAD Reflex Sight
Agena SWA 38mm 70 FOV 2" EP
Orion 25+10mm Sirius Plossl 52 FOV EP
ES 82* 11mm, 18mm 2" ES 68* 24mm
6mm, 25mm Ortho. EP
Televue 3X Barlow
Filters Baader Continuum, UV/IF cut, Lumicon UHC, DGM OIII.
SkySafari T-Ring and Adaptor for Olympus E-510 Oly sz-14 SteadyPix Deluxe iOptron SkyTracker 7.7lb Electro Dot Sight RD400X
Quote: Quote:I find that grabbing the tube isn't the best method.But why do u think grabbing the tube isn't the best method? I think otherwise...that grabbing the tube gives more control when nudging at high powers.. In fact while moving the telescope I habitually hold both ends of the tube to have maximum control on the motion.Clear Skies!
Quote:a knob seems like an unnecessary extra...just more weight.
We mostly come out at night... mostly.
GSO Z8 Degree Circle & Digital Level
Celestron 4"(102mm) SLT 660mm f/6.47
2" 30mm GSO WideView
9mm GSO Plossl
ES 82's : 4.7mm, 8.8mm, 11mm, 18mm
BGO's 5mm, 6mm, 9mm
2" 2X ED Astronomics Barlow & GSO 1.25" 2x Shorty
8-24 Baader Zoom III
Baader M&SG, Semi-Apo
Zhumell Z10 Dobsonian 10" Comes with 30mm 2 inch, 9mm 1.25 inch eyepieces Highpoint Scientific 2 inch 2X ED Barlow (made by GSO) Celestron SLT102 Refractor Orion Starblast 80mm AutoTracker Refractor Comes with PL 25mm,10mm SkySafari Plus, SkEye Pro
Ken Fiscus- stargazing since 1980. Now observing from a green zone.
Z12 on custom mount, Atomic EQ platform, 100% flocked, OMI primary, Astrocrumb filter slide with O-III, NPB, & skyglow filters. Focuser & spider rotated 45 degrees. New springs & Bob's Knobs, Telrad & 9x50 straight finder 35 & 24 Pans, TV 13,7,5 T6s
Custom Orion XT10 with piggyback XT4.5 on Round Table EQ Platform
Quote:i have never heard of heat from the hand having any effect on tube currents. turn on your fan and forget the knob.
Quote:Quote:i have never heard of heat from the hand having any effect on tube currents. turn on your fan and forget the knob. A tube current caused by your body heat is not something you hear, it is something that you can see through the eyepiece. To see the effect of your body heat, you need to start with a thermally stable scope. Point the scope at bright star using a moderate magnification (200x) and defocus the image, place your hand in front of the scope and you can see the heat rising. If the seeing is sufficiently stable you can see the effect of just touching the tube with your warm hand.I have owned my trusted 10 inch F/5 Made in Taiwan GSO Dob for about 10 years. On an excellent night, it is capable of resolving double stars at the Dawes Limit.. 0.5 arc-seconds, about one fifth the separation of the double-double. Using gloves is one trick I learned that makes this possible.Jon
Quote:Quote:i have never heard of heat from the hand having any effect on tube currents. turn on your fan and forget the knob. A tube current caused by your body heat is not something you hear, it is something that you can see through the eye front of the scope and you can see the heat rising. just touching the tube with your warm hand.Jon
6'' Orion SkyQuest f/5 12.5" Astrotel truss dob f/3.3 20" Super FXQ Starmaster William Optics 80mm ZenithStar ED II 1855/2500 Observing sessions grand total for 2013, 49. So far in 2014, 14
WO Megrez 120 ED on GP Mount
WO ZenithStar 80 ED II on Porta II
10" Meade LightBridge/Paracorr
Orion ED 100 on Polaris Mount
Astro-Tech 8" f6 Dob
Bushnell Ares 5
Meade 226 2.4" f11.7
SpaceScope 2.4" f15
- Dan Zhumell Z8 Dobsonian (A.K.A. "The Cannon") Zhumell 30mm, 2" Wide Field Zhumell 9mm 1.25" Plossl Custom made setting circles and a Wixey digital level