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The horsehead in light pollution?

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#1 Darren Drake

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Posted 05 October 2021 - 06:44 AM

Can NV along with an Ha filter show something as dim as the horsehead from the Chicago suburbs?  I have just ordered a unit from TeleVue and hope to try this in my 18 inch soon and was just wondering what other's experience are on this.  Thanks 



#2 stnagy

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Posted 05 October 2021 - 06:52 AM

Yes, especially with your aperture. If you look on the pinned photo thread, you'll see a few images of the Horsehead taken with much smaller apertures. With 18 inches I expect you'll be able to observe most of the Sharpless catalog. 



#3 bobo99

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Posted 05 October 2021 - 07:03 AM

Can NV along with an Ha filter show something as dim as the horsehead from the Chicago suburbs?  I have just ordered a unit from TeleVue and hope to try this in my 18 inch soon and was just wondering what other's experience are on this.  Thanks 

I've seen it with an 8" and a 7nm filter. You'll be just fine with the 18" and a filter.



#4 chemisted

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Posted 05 October 2021 - 07:15 AM

Can NV along with an Ha filter show something as dim as the horsehead from the Chicago suburbs?  I have just ordered a unit from TeleVue and hope to try this in my 18 inch soon and was just wondering what other's experience are on this.  Thanks 

Congratulations on joining the intensifier community.  I hope your unit arrives soon.  You will have great fun seeing the Horsehead and I would recommend you read the following article to acquaint yourself with this bit of amateur astronomy history:

 

https://www.cloudyni...i3-system-r1602


Edited by chemisted, 05 October 2021 - 07:18 AM.


#5 ButterFly

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Posted 05 October 2021 - 08:08 AM

The HH is big.  And it's a dark nebula.  It would look better in a slightly smaller focal length scope only because more of the actual emission nebula is visible that way.  The 67 Plossl is the way to go, and take out the Paracorr to help get some more field.

 

The 8 or 12.5 may be better to see the whole thing.  Going up in aperture always improves resolution.  But, the scope's focal ratio determines its light gathering ability, rather than its aperture - NV is imaging after all.  Fortunately, as aperture gets bigger, focal ratios tend to go down so things stay human sized.  That typically means more resolution and light gathering, at the expense of less field of the longer focal length.

 

Try all your scopes and decide for yourself.



#6 bobhen

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Posted 05 October 2021 - 10:31 AM

Can NV along with an Ha filter show something as dim as the horsehead from the Chicago suburbs?  I have just ordered a unit from TeleVue and hope to try this in my 18 inch soon and was just wondering what other's experience are on this.  Thanks 

I live in the Philadelphia Suburbs under a Bortle 8-9 sky.

 

I can easily see the Horsehead with my 120mm refractor. As a matter of fact your 120mm F5 “finder” might be one of the better scopes you have to use with NV, especially for some very large nebulas like the Horsehead, Rosetta, North American etc. all of which are easy with an intensifier and a 6nm Ha filter. You will want to add a Ha filter for nebula and a 685 Pass filter for non-nebula objects. 

 

NV is a somewhat new way of observing/thinking and you will soon discover the majesty of low power, wide field observing using small 4-6” fast Newtonians or 80-120mm fast achromatic refractors along with a larger scope. Most NV users also use camera lenses or 50mm guide scopes for extreme, low power, wide field observing. Objects like the Monkey Head Nebula, which are considered CCD imaging targets, are also easily seen with NV.

 

BTW, using a 50mm handheld guide scope from Philadelphia I have seen the “brighter” sections of Barnard’s Loop in Orion, which is fainter than the Horsehead.

 

A nice group of telescopes to use with NV might be something like…
1. Wide field camera lenses or a 50mm repurposed guide scope, all can be handheld
2. A fast, small 4-6” Newtonian or 80 to 120mm fast F5 achromatic refractor.
3. A larger 8-11” SCT or 10 to 18” Dobsonian.

 

Because an intensifier supplies enough light for any telescope, NV isn’t so much about aperture (like normal observing) as it is about FL, field of view and image scale.

 

I’m positive you will be thrilled.

 

Bob



#7 pwang99

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Posted 05 October 2021 - 11:40 AM

I've seen the HH from urban light dome, but I've found that 120mm or smaller fast refractors seems to do better than a larger reflector.  Something something surface brightness and contrast... :-)



#8 Jeff Morgan

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Posted 05 October 2021 - 01:32 PM

Can NV along with an Ha filter show something as dim as the horsehead from the Chicago suburbs?  I have just ordered a unit from TeleVue and hope to try this in my 18 inch soon and was just wondering what other's experience are on this.  Thanks 

Order a h-alpha filter if you have not already done so. Also, get a helmet with a chin strap. This prevents injuries from the jaw-dropping you are about to experience.

 

Here is what the HH looks like in a slightly smaller scope, slightly better sky:

 

https://www.cloudyni...ery/?p=10234211

 

Obviously nebula are an entirely new game, but don’t forget star clusters. The gains there are almost as … astronomical. 


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#9 johncmcd

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Posted 07 October 2021 - 12:31 PM

Hi Darren,

 

I am very eager to see exactly the same thing.  I live just north of Chicago and have a balcony that faces south-east right over downtown.  Luckily I have a building right across from me that blocks direct light, but the light pollution is, of course, extremely heavy (is there a Bortle 11? ... sure feels like it sometimes :)  Mostly I am relegated to observing brighter open/globular clusters and planetaries via UHC. So, while it has been fun to struggle through the LP to see the objects on the AL Urban Observing program, including the galaxies which filters don't really help on, the novelty of hunting for detail-less objects, that in a dark sky would be easy, bright, and full of detail, wears off after a few years.

 

So, like you, I put in an order with Televue for the same unit and really can't wait to see what it'll bring out.  Given my level of light pollution, I'll be ecstatic if I can pull out good views of globulars with the use of a 640 or 685nm IR pass, and the brighter nebulae with a 7 or 3nm Ha, which seems highly likely given the general discussion on this forum. But if in fact, we can see objects like the Horsehead, Flame and North America through this soup ... one can only hope, but again, the reports I've read from people observing from London, San Francisco, and even here in the Midwest give me hope ... enough to hold out during the 6 month wait for the pvs14 :)

 

Clear skies and can't wait to see what this thing will do at Green River,

 

John

 



#10 Darren Drake

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Posted 07 October 2021 - 01:31 PM

John my unit will arrive later today!  To say I'm excited is an understatement.  I have people over for observing all the time with my many scopes and I will no doubt be having many interested in seeing how this thing does.  I pretty much know what to expect as my night with the T.V unit at WSP was life changing.  I will send you a PM.


Edited by Darren Drake, 07 October 2021 - 01:44 PM.


#11 ButterFly

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Posted 07 October 2021 - 03:55 PM

Going back and forth between the 80mm and the dob is fun with Gamma Cyg.  It has lots to offer at every image scale.


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#12 GOLGO13

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Posted 07 October 2021 - 04:27 PM

One thing to remember with NV, from my perspective, is not to judge your view based on one or two night's observations. 

 

Maybe this is related to my local sky conditions, but I can see a very large difference night to night depending on the sky.

 

I've had some nights the Horse Head is barely visible and some nights it's pretty good. It is somewhat faint in general. Fast scopes or greatly reduced scopes are helpful.

 

Also this is an object where some nights I found the 12nm HA filter worked better than a tighter HA filter. All of that depended on the scope and setup being used. I wouldn't say you "need" to get a 12nm filter, but I did find cases where it was useful, and the Horse Head was one of those. Especially if the sky was inhibiting the view.

 

My skies are Bortle 6 and I've not tried it in heavier light pollution (or even less light pollution).

 

Image scale can help for seeing the dark nebula portion. With a smaller scope or not enough magnification it just looks like a notch without the nose. Your 18 inch Darrin should help quite a bit here. I think if you were to pair the 67mm TeleVue setup with the 18 inch the Horse Head should be pretty darn good.


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