Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Well guys,
I just came in from a short trip with my Nighthawk in search of a slightly darker location than my front yard.
The conditions:
I found a spot in the back of an old ballfield that was a 60% improvement over the streetlights at my house. There were still enough lights around the place that my eyes could never dark adapt. The sky was washed out to the South, but in the middle of Sag. the skyglow decreased considerably. The bottom of the teapot was washed out, but the star at the top was bright on the background sky.
Equipment: SV Nighthawk with an LV 8-24 zoom EP.
With the SV Nighthawk I worked really hard to bag M55 (GC), and I finally did it - but only with averted vision. It took a long while to first find it, then confirm it due to the skyglow issues. One of those "I found it !!!, Wait - I lost it..., There it is, Darn - where did it go..." Type of experiences.
I then switched my attention to M57 (PN), and I was able to bag it - but it was barely visible with direct vision. It jumped out at me with averted vision - nice little fuzzy donut.
Alberio (DS) was next on the list, absolutely beautiful double with a nice contrast between the orange and blue stars.
M27 (PN) was the next target of choice. MUCH easier than M57 !!! Easily visible with direct vision and it appeared to be a fuzzy blocky rectangle with a slight dip in either side of it. It held magnification well.
At this point I decided to pack up the Nighthawk. After tucking it away in the truck, I decided to break out the Oberwerk 11x56 binos for a little sky sweeping.
WOW, these things work really well on DSO's !!!
I found M55 with direct vision - compared to averted vision in the Nighthawk. I then found M22 (GC), M20 (N), M8 (N), Alberio (DS), and for the first time ever in binos - M27 (PN) !!! I didn't realize that it was possible to bag M27 with binos.
Overall it was a very successful night ! I am very happy with the performance of both the Stellarvue Nighthawk and the Oberwerk 11x56 binos. 
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  Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Tom L
Reged: 01/07/04
Posts: 29817
Loc: Sunny Oregon
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I have enough trouble with M27 in my 8" Dob. Good catch, Scott! Binocs are a lot of fun to use.
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Tom 
Tele Vue 102mm f/8.6 on an EzTouch
Vixen 80mm f/5 A80SSWT on a grab-n-go mount
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Thanks Tom. I think this was my best DSO night yet - considering I was using 80mm and less.
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Tom L
Reged: 01/07/04
Posts: 29817
Loc: Sunny Oregon
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I know how you feel about the 11x56s. I really enjoy using my 10x50s hand held and will get out atleast once a night (skies willing) just with the binocs for a few minutes. Nice way to "check-in". Sounds like the nighthawk was having some trouble though...M57 is always a much easier target for me over M27...now that I have a personal vendetta with M56, I always check in on it every chance I get.
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Tom
Tele Vue 102mm f/8.6 on an EzTouch
Vixen 80mm f/5 A80SSWT on a grab-n-go mount
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Tom,
Tonight M27 just jumped out and screamed "here I am". It was so easy. M57 was really nice with averted vision, but just "o.k." with direct vision. Can't explain it - but that is how it was...
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Carol L
Reged: 07/05/04
Posts: 5880
Loc: Tomahawk, WI 45N//89W
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Fantabulous, Scott.. ya done good!!!!
I'd always wondered why they called M27 the Apple Core nebula till I saw it with the 22x100 binos. Like you said, it looks like there's a slight dip [bite?] out of either side.
It's funny, but with all the talk of 'aperture rules' out there, I'm enjoying DSOs more than ever since powering down with the binos over the summer. I'm going to work the 22x100's and the 11x70's side by side as often as possible, too... might be interesting.
Btw, did you ever get Machholz yet? Iirc you were going to try sometime this weekend.
Great report, and congrats! 
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 *Step-by-Step Lunar Sketching*
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Bill Grass
Prince Regent
Reged: 10/07/03
Posts: 11652
Loc: Denham Springs, LA
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Great report, Scott! Sounds like a fun night.
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Chutzpah
sage
Reged: 08/26/04
Posts: 228
Loc: Cheshire, UK
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Nice report. It's a great feeling when you bag a faint one with a small scope. My sympathies for those local skies of yours, though - that's some serious light pollution.
Hey, and if you get a lot of local light glare to stop you dark-adapting, have you looked at these things:
http://www.kendrick-ai.com/astro/observatory.html#Shelter-Dome
The one being offered on that site is way too expensive, but I've been thinking about a quick set-up home made screen that might make things a lot easier in the back garden.
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Stevie
8" f6 Newt
MN56 5" Mak-Newt
10x50 binos
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12565
Loc: Cumberland, R I , USA42N71.4W
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Nice going Scott,
I have an AT1010 I use sometimes. But I've always got binoculars out with me, no matter what scope.
When you're scouting around in the vicinity of M27, drop south 3° and look around the front section of Sagitta the arrow for the very faint globular cluster M71. You might have trouble with this one if skies are washed out.
One of the reasons you can see so much more than you thought with 11x56 binoculars is due to binocular summation. You get to look with two eyes. The brain, what little brains we have, processes 20% to 40% more infomation when seen with two eyes. Some texts will say you see 40% better contrast but only 20% greater light gathering.
The total area of the aperture you are using is really sqrt[(piR256)+(pir256)]= the equivalent of 1.414 x 56 = 79mm of aperture. So not only do you have an equivalent 79mm aperture, but you have a 5mm exit pupil giving a very bright image. Seldom do we ever use telescopes at low enough powers to get 5mm exit pupils.
The AT1010 is 80mm/480 (really only 78mm, but let's use 80). To get a 5mm exit pupil you would have to use an eyepiece that is giving 16x, a 30mm.
I've done some tests where I've observed an open cluster, M44, with Fujinon 16x70s and compared the number of stars seen (within a strict boundary) side by side to the AT1010 at 16x (16x78 with 4.9mm e.p.)and to a TV85 at 15x (15x85 with a 5.66mm e.p.). These scopes bracket the Fujinons. More stars were seen in the Fujinons. Why? Seems like the only answer could be, Two Eyes.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Carol,
The comet has escaped me for this weekend - but I will track it down.
Thanks Bill.
Stevie,
I appreciate the tip. The streetlights at my house are as close as 35' away making some of them "overhead lights". In my home location a screen would not help.
Ed,
I knew that there was a 40% difference in perception with binos, but I am seeing double the nebulosity with my binos that I see in either the Nighthawk or the ED80 when at approx. 12x with either one. I mean the difference is astounding. I thought they would equal out, but it is a big difference. Both globs and nebulae jump out at me in the binos and it just doesn't happen in the scopes. My CR150 crushes the bino's but we are talking about 6" of aperture. I don't have an answer for this yet...
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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DenisY
Carpal Tunnel
Reged: 01/10/04
Posts: 2048
Loc: Canada / Montréal
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Nice report Scott, Ed pointed out exactly what i was going to say, you were sooooo close to M71! Just a little lower and a little to the right and voila! But M71 compare to M27 is vey faint in some light polution.
Your binoc proves one thing. ALL beginner astronomer should start with this. Perfect tool for observing from what i hear.
Happy for ya! 
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Denis
I wonder how would the world be different if
Einstein had never lived?
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Thanks Denis,
I had a really good time last night.
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Jeremy Perez
Carpal Tunnel
Reged: 08/12/04
Posts: 1669
Loc: Flagstaff, Arizona, USA
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Congratulations on M55 and the others Scott. I enjoyed the report.
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Orion SVP 6LT (6" f/8 Newt) || Orion XT8 (8" f/6 Newt) || 15x70 Oberwerk Binoculars
The Belt Of Venus || Astro-Sketch Gallery || Astro-Sketching Resources || Astro-Photo Gallery
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Thank you Sir. I realized I missed a couple in the same general area that I should have looked for. Didn't break out my Skymap - just went from memory. Went back and reviewed the chart and realized there were a couple more that might have been "easy pickins".
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12565
Loc: Cumberland, R I , USA42N71.4W
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Scott,
Have you ever attempted to measure your fully dilated eye pupils? Mine are very large at 6.5mm in one eye and approaching 7mm in the other. Most people over 40-50 have eye pupils at a maximum about 5mm maybe 5.5mm.
Your were using your 80mm scope at 12x. That's an exit pupil of 6.67mm. Did it ever occur to you if you have an exit pupil larger than your eye pupil, then your eye is creating an effective aperture. If your eye has a limit of 5.5mm, then your eye is stopping down the scope to an effective aperture of 5.5x12 = 66mm. So, when you try using those extremely low powers in your scope , you scope may not be funtioning like an 80mm scope.
Check your eyes, or have someone check for you. You need to know the maximum size of your dark adapted eye pupils to know how big of an exit pupil you can use without wasting light.
Your binocs have an exit pupil of 5.1mm. If your eyes pupil doesn't get any larger than that, then at 12x your scope is operating as if it were 61mm. If that's the case, your binocular would have 70% more light gathering than your scope (when your scope is used at 12x).
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Ed,
Last night with the surrounding street lights - my eyes definitely did not dialate to the maximum possible. I would say minimum to no dark adaptation, which is still better than the blindingly close streetlights at my house. I can read a book outside without the assistance of extra lights at my house.
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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Carol L
Reged: 07/05/04
Posts: 5880
Loc: Tomahawk, WI 45N//89W
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Geez, Scott.. if I went from memory
I'd be 'lost in space'. 
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*Step-by-Step Lunar Sketching*
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Carol L
Reged: 07/05/04
Posts: 5880
Loc: Tomahawk, WI 45N//89W
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Quote:
Have you ever attempted to measure your fully dilated eye pupils? Check your eyes, or have someone check for you. You need to know the maximum size of your dark adapted eye pupils to know how big of an exit pupil you can use without wasting light. edz
The question is, how to measure your pupils?
I'd read a message [Yahoo, iirc] that someone vertically holds different sized Allen-wrenches closer and closer to their eye [when it's fully dilated] while looking at either a star or a planet. When the target either merges or separates [can't remember which.. kind of like the fingertips-in-the-middle when we bring our index fingers together in front of our noses], they note the size of the wrench and that's their pupil size.
Anyone ever hear of this?
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*Step-by-Step Lunar Sketching*
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Carol,
That is why I missed some of the closer DSO's.
Ref your second post, I would probably stick an allen wrench in my eye - I think I would let a Doc test it for me.
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12565
Loc: Cumberland, R I , USA42N71.4W
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Carol
and Scott,
I'ver heard of the allen wrench method. Not my favorite. I don't use that method.
Here's what I do. From some star charts you might have around, make a photocopy of the legend where it shows different sizes of dots for the magnitude of stars. Then with a straight edge and an exacto knife, cut right thru the middle of all the dots (on your photocopy). I used SkyAtlas 2000.0. In the legend, it has black dots from very tiny up through 7mm, in half mm increments. Once you have cut this in half you have exactly what your optometrist would use to measure your pupils, a series of half dots. His is on a plastic ruler.
Stand in a darkened room with a mirror and hold the sheet of paper with the half dots in front of your eye. It is surprisingly simple to see which half dot matches exactly to the size of your pupil. You might need a little light in the room. Use background light or use very low (maybe red light) nearby. Once you find the half dot that matches your eye, measure the half dot.
The fact that it's red light makes no difference here, except that it's very low light. This is not dark adaptation, this is pupil dilation. You pupils will dilate to maximum within a few seconds. Dark adaptation of the rhodopsin in your eyse takes 30min to 2 hr. and can be lost in seconds.
Any exit pupil you use that is larger than your eye pupil effectively reduces the aperture of your optics. It'll give you a wider field of view, but it will reduce your light. If it's maximum light you trying for, then never use an exit pupil larger than your eye pupil.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Scott Beith
SRF
Reged: 11/26/03
Posts: 33042
Loc: Gulfport, MS
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Thanks Ed. You are handy to have around. 
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Scott
"The only thing necessary for the triumph of evil is for good men to do nothing." -- Edmund Burke.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell
"The measure of a man’s greatness is not determined by what he accomplishes for himself, but by what he accomplishes for others.” -- Some Bald Guy
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12565
Loc: Cumberland, R I , USA42N71.4W
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that's what my kids say.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Chris Graham
mmmm...Haggis
Reged: 04/01/04
Posts: 4869
Loc: Stirling, Scotland
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That was a great report Scott.
My back yard must be quite good, coz i can see M57 no problem. Only main gripe i have is that the ring is so small.
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-Skywatcher 8" Reflector on HEQ5 with Skyscan
-Orion ED80 Refractor
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Astronomy & Veggies
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NewAstronomer
Carpal Tunnel
Reged: 09/03/04
Posts: 2690
Loc: Scranton, PA U.S.A
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So Edz, if I allow only a few minutes in the darm room with a mirror, my pupils will be at max size and this measurement will tell me what max exit pupil I should be using ? I understand this is not dark adaptation, however what I don't understand is how do I determine what the exit pupil for my scope or EP is ?
For instance just divide apeture by mag ? That easy? It seems then if you use higher mag, you'll compensate for smaller pupils ? Or am I way off base ?
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Chris
AT66ED f/6
C80ED f/7.5
10" GSO Dob f/5
SVP w/ autoguide mod
Oly E-500 DSLR, DSI-P, DSI-C, NexImage
Edited by NewAstronomer (10/18/04 11:08 AM)
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ArizonaScott
Postmaster
Reged: 04/29/04
Posts: 5028
Loc: Phoenix, AZ
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Nice report Scott!  (sorry for jumping in so late). I get more satisfaction from hunting down DSO's with my ST80 than I do from seeing them easily with my 8", and starhopping is a lot easier with the little guy. I've been able to locate about half of the Herschel 400 with it, but the rest are way too dim so I'll be lugging around the 8" from now on 
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Scott
10" LX200 Classic, Konus 200, Orion ST80, ETX90 OTA, 60mm Celestron alt-az, Obie 20x80's, Meade 10x50's
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ArizonaScott
Postmaster
Reged: 04/29/04
Posts: 5028
Loc: Phoenix, AZ
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BTW Scott, if you don't already own the book Astronomy With Small Telescopes I highly recommend buying it. There's a chapter by Dave Mitsky on the ST80 that I find very inspiring for hunting down DSO's. Jay Reynolds Freeman has a chapter on DSO observing skills in which he notes that he's seen most of the H400 with his Vixen 50mm refractor, under excellent conditions and with every shred of skill he could muster, of course
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Scott
10" LX200 Classic, Konus 200, Orion ST80, ETX90 OTA, 60mm Celestron alt-az, Obie 20x80's, Meade 10x50's
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12565
Loc: Cumberland, R I , USA42N71.4W
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Quote:
So Edz, if I allow only a few minutes in the darm room with a mirror, my pupils will be at max size and this measurement will tell me what max exit pupil I should be using ? I understand this is not dark adaptation, however what I don't understand is how do I determine what the exit pupil for my scope or EP is ?
For instance just divide apeture by mag ? That easy? It seems then if you use higher mag, you'll compensate for smaller pupils ? Or am I way off base ?
In fact, very quickly your pupils will dilate to maximum. You won't need to wait a few minutes. However, with some low light in the room that you will need to see in the mirror, you might not reach total maximum. Therefore, a good assumption might be to add a half mm to the reading you get as your maximum. Half mm is about the difference I get when I measure compared to what my optometrist measured. Even he had to use a low light to see well enough to get a reading.
Exit pupil for your scope is either aperture divided by magnification or eyepiece focal length divided by scope f#.
Yes, if you use higher magnifications you will always get smaller exit pupils. But that won't always provide you with the right combination to see all objects, so many times it's the wrong choice. I challenge you to find M74 at higher magnifications. There are a number of low surface brightness objects that do much better when you optimize maximum brightness rather than use high magnification. Objects that come to mind are M101, M33 and M74. All three of these I found in binoculars before I ever saw them in a scope.
My binoculars have exit pupils of 4mm or 5mm. Sure I could use eyepieces that would give me large exit pupils in my scopes, but I usually don't. For several years, I had scopes of f/11 and f/8. I have a 40mm eyepiece, but more often than not I use my 30mm. So the largest exit pupils I was getting with my scopes was either about 3mm or 4mm. I first found M101 with a 16x80 binocular with a 5mm exit pupil. I first found M33 with a 10x50. The only instrument with which I have ever seen M74, the Merope Nebula and the Rosette nebula was a 100mm binocular telescope at 24x with a 4.2mm exit pupil.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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NewAstronomer
Carpal Tunnel
Reged: 09/03/04
Posts: 2690
Loc: Scranton, PA U.S.A
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Re: DSO Success with Small Apertures
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