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Equipment Discussions >> Electronically Assisted Astronomy

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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
M82 Galaxy Real-Time HD Video thru IIE at 120X
      #5735438 - 03/16/13 01:41 AM

Got another real-time HD video for you taken thru a Mewlon 250 scope and a Gen 3 image intensifier from a dark site. Magnification is 120 power.

You'll get the sharpest video by using an HD setting.

Enjoy!

M82 HD Video Link


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PEterW
professor emeritus


Reged: 01/02/06

Loc: SW London, UK
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5735509 - 03/16/13 04:23 AM

Is the scope operating at f12? Are the views similar to the eyepiece? You seem to like the cold!

Cheers

PeterW


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nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5735550 - 03/16/13 05:31 AM

Quote:

Got another real-time HD video for you taken thru a Mewlon 250 scope and a Gen 3 image intensifier from a dark site. Magnification is 120 power. You'll get the sharpest video by using an HD setting. Enjoy!
M82 HD Video Link


Nice M82 YT video - I like your longer exposure 'still' examples as obviously much smoother and the severe video 'sparkle' is absent

Just an aside - I'm puzzled by your reference to "HD" - does that mean recording the output screen via a HD cam or that the IIE is HD? Isn't the limiting factor the IIE screen resolution rather than the cam potential resolution. Just asking


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PEterW
professor emeritus


Reged: 01/02/06

Loc: SW London, UK
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: nytecam]
      #5735627 - 03/16/13 07:55 AM

IIE tube resolution typically around 64lines:mm, tube 18 mm across, giving 1150"pixels", so similar to HD. I guess the poster had used an HD resolution camera. Newer tubes can give higher resolution, but are less available.

PeterW


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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: PEterW]
      #5736652 - 03/16/13 04:59 PM

Quote:

Is the scope operating at f12? Are the views similar to the eyepiece? You seem to like the cold!

Cheers

PeterW




Yes the scope is operating at it's native speed of f12. The video views are slightly dimmer (~ 50%) and slightly grainier than the view seen with just the eye looking into the intensifier ocular. Regarding the cold, I'm anxiously awaiting warmer weather.


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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: nytecam]
      #5736664 - 03/16/13 05:11 PM

Quote:

Just an aside - I'm puzzled by your reference to "HD" - does that mean recording the output screen via a HD cam or that the IIE is HD? Isn't the limiting factor the IIE screen resolution rather than the cam potential resolution. Just asking




Yes I am recording the video in HD mode (1920x1080/60i). This image tube has a resolution of 64 line pairs per mm. I'm not sure how that translates into pixel resolution. Since my Mewlon 250 is operating at f12, on a dim target like a galaxy, the tube resolution may be lower than 64 lp/mm. If I shoot the video in standard definition, it will look noticeably lower res than using the camera's HD video mode. BTW, my camera is a Panasonic Lumix DMC-G5. I'm already looking into finding a camera with even better low light sensitivity since the video it produces shows less detail than the naked eye view looking into the intensifier ocular.


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nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5738043 - 03/17/13 05:41 AM

Quote:

Quote:

Just an aside - I'm puzzled by your reference to "HD" - does that mean recording the output screen via a HD cam or that the IIE is HD? Isn't the limiting factor the IIE screen resolution rather than the cam potential resolution. Just asking




Yes I am recording the video in HD mode (1920x1080/60i). This image tube has a resolution of 64 line pairs per mm. I'm not sure how that translates into pixel resolution. Since my Mewlon 250 is operating at f12, on a dim target like a galaxy, the tube resolution may be lower than 64 lp/mm. If I shoot the video in standard definition, it will look noticeably lower res than using the camera's HD video mode. BTW, my camera is a Panasonic Lumix DMC-G5. I'm already looking into finding a camera with even better low light sensitivity since the video it produces shows less detail than the naked eye view looking into the intensifier ocular.


Well done - many thanks for the clarification

Decades ago I had a play with Gen 1 EODs in a three-stack and single stack on my 17-1/2" f/4.4 Coulter Newt. Images were very noisy.

I was acutely aware that output screen was radiating a full hemisphere of light [much like a tv screen] and only a fraction of that light was captured by a fast large optic camera placed before it. As an experiment I reversed the polarity of the single EOD to 0v on the output screen [it still worked fine!] and placed a strip of Ilford HP5 35mm film in physical contact with the screen to capture ALL the light emitted! Results were obviously much brighter but I didn't persue it as too inconvenient. But what if today you could bond a large mono CCD [from a debayered DSLR like Canon 1100d] in contact with a modern EOD output screen - what a camera that would be!


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Ptarmigan
Lagopus lagopus
*****

Reged: 09/23/04

Loc: Arctic
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5738758 - 03/17/13 02:37 PM

Cool.

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highfnum
Carpal Tunnel
*****

Reged: 09/06/06

Loc: NE USA
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: Ptarmigan]
      #5738995 - 03/17/13 04:02 PM

can you upload drawing on how you record fromm IIE device

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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: highfnum]
      #5739332 - 03/17/13 06:26 PM Attachment (9 downloads)

Quote:

can you upload drawing on how you record fromm IIE device




This pics shows the method of image capture that I have been using. Components include (from left to right): Panasonic DMC-G5 micro 4/3rd's camera, Voigtlander 17.5mm f0.95 lens, 58mm to 46mm step down ring, night vision camera adaptor (46mm thread / split ring), and finally the image intensifier unit. This pic shows a Micro Monocular but I have been using an ITT 6010 Night Enforcer monocular with the same type of ocular. The Computar c-mount lens in front of the intensifier unit (far right) is replaced with a c-mount 1.25 inch telescope adaptor for plugging the whole assembly into a telescope.


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highfnum
Carpal Tunnel
*****

Reged: 09/06/06

Loc: NE USA
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5739440 - 03/17/13 07:07 PM

Nice
But it looks heavy what is weight?
Does first lens sit afocal to eyepiece?


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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: highfnum]
      #5739955 - 03/18/13 01:22 AM

Quote:

Nice
But it looks heavy what is weight?
Does first lens sit afocal to eyepiece?




I think the weight of the camera and lens is close to 2 pounds. The ocular on the intenfier unit has a very strong eyeguard ring that threads into the ocular housing and is secured with blue thread locker. I have been assured by a Night Vision supplier that the ocular can take the weight. So far no issues.

Yes, the Voigtlander lens connects afocal to the intensifier ocular. The Computar lens would be replaced with a c-mount 1.25 inch or 2 inch telescope adapter for telescope use.


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highfnum
Carpal Tunnel
*****

Reged: 09/06/06

Loc: NE USA
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5740315 - 03/18/13 09:32 AM

and how is it mounted to scope?

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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: highfnum]
      #5740906 - 03/18/13 03:07 PM

Quote:

and how is it mounted to scope?




Removal of the c-mount lens (Computar 50mm in this case), allows for adding this part: 1.25 inch c-mount scope adapter or this part Baader 1.25 inch c-mount scope adapter and slipping it into a 1.25 inch telescope focuser opening.


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PEterW
professor emeritus


Reged: 01/02/06

Loc: SW London, UK
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: jdbastro]
      #5741100 - 03/18/13 04:40 PM

Which camera/c mount lenses do you use?

Cheers

Peter


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jdbastro
sage


Reged: 08/18/07

Loc: W. Coast
Re: M82 Galaxy Real-Time HD Video thru IIE at 120X new [Re: PEterW]
      #5741260 - 03/18/13 05:47 PM

Quote:

Which camera/c mount lenses do you use?

Cheers

Peter




I have used various 1-inch format manual c-mount (TV lenses) including the following:
Computar 25mm f1.3 for 1X
Computar 50mm f1.3 for 2X
Fujinon 50mm f1.4 for 2X
Navitron 50mm f0.95 for 2X (lots of coma wide open)
Computar 75mm f1.4 for 3X
Cosmicar/Pentax 75mm f1.4 for 3X
Fujinon 75mm f1.8 for 3X
Canon 100mm f2 for 4X
Computar 135mm f1.8 for ~5X

And various legacy T-mount lenses (all manual focus/aperture) with a c-mount to T-mount adaptor. The lenses I have tried are:
Spiratone 105mm f2.5
Lentar 135mm f1.8
Lentar 200mm f4.5
Lentar 300mm f5.5

All of the above provide low power, wide field views, unlike a typical telescope, but these lenses will yield a brighter view since a typical telescope has f ratios in the f4 to f12 and slower range.

Finally, one can even use various other SLR lenses together with a corresponding c-mount adaptor. I've tried this with a few Nikon lenses.

The native c-mount TV lenses tend to be the lightest weight.
Legacy T-mount lenses tend to be the least expensive to acquire used.

Hope this helps.

Edited by jdbastro (03/18/13 05:48 PM)


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