[Lvas] Green Lasers
Phillip Krumpos
PhilJ1945 at cox.net
Tue Dec 18 11:21:40 PST 2007
All I can say is wow!!! Those are beautiful photos. How did you capture them? Did you enhance them with Photoshop?
----- Original Message -----
From: Martin Suñer Hilario
To: Las Vegas Astronomical Society
Sent: Monday, December 17, 2007 11:54 PM
Subject: Re: [Lvas] Green Lasers
I would like to share some of my images with you from the mallincam yahoo groups. The images were taken at Lake Mead last weekend with an older Mallincam pro dob and a dobsonian telescope. Objects include: Horsehead, NGC253, M33, M81, and others.
Link: http://picasaweb.google.com/mhilario2/Redstone122007
I hope to get good results for public outreach with the color hyper camera also.
To Phil,
I wish you and your daughter the best in selecting your telescope for the mallincam. I'm sure that the both of you will be happy with your choice.
The wait time for the mallincam seems to be in the order of two months, as I am still waiting for an order placed several weeks ago. So I am sure that you will have ample time to select your telescope.
I do not have experience with it yet, but many users recommend the color hyper plus camera over the black and white version. It is time consuming to make RGB astrophotos from the black and white camera with the computer - plus the color contrasts enable you to see details in objects more easily and live on a portable tv monitor or 10" dvd player.
Regards,
Martin H
On Dec 16, 2007 8:31 PM, Phillip Krumpos <PhilJ1945 at cox.net> wrote:
I greatly appreciate all of your advise on selecting a telescope for use with a Mallincam. It will take me awhile to digest all the information you have provide. My daughter has aperture fever, so it may take awhile for us to select the right scope. I will keep you inform on our progress.
----- Original Message -----
From: Martin Suñer Hilario
To: Las Vegas Astronomical Society
Sent: Sunday, December 09, 2007 10:55 PM
Subject: Re: [Lvas] Green Lasers
Phil,
Focal reduction or having a short focal ratio telescope is the key when choosing a telescope with a mallincam. Focal ratios of f/2 to f/4 work best. You can achieve those focal ratios by getting a "fast" optical system or by getting a focal reducer like this:
MFR-3 Focal reducer plus 10mm ring (multiplies focal ratio by ~0.67x)
http://www.waningmoonii.com/Updates%20-%20July%202005/MallinCam%20Included%20and%20Optional%20Equipment.htm .
In the apochromatic refractor category, I recommend a short focal ratio refractor like the Takahashi FSQ106 or Televue TV101 f/5 (~2400 USD on astromart.com). 3 to 4" f/7 apo refractors or even 3 to 5" f/5 rich field refractors like the orion/synta ones are good too, when used with the MFR-3 focal reducer. These refractors are lightweight and absolutely wonderful for viewing large, extended objects like the lagoon, m42, m20, m33, etc. In my opinion, they actually give good images for smaller objects as well although someone else will think otherwise.
I have had excellent results with a modest 80mm f/5 achromatic refractor with and without focal reducer for these large objects.
I would also like to recommend an 8-10" SCT or Ritchey-Chretien with an F/3.3 focal reducer and GOTO for ease of use with the camera. The larger aperture, similar focal length, and short focal ratio will allow you to view a greater number of objects with shorter exposures with the Mallincam. Also, the 8" SCT can operate at f/6 with the Mallincam MFR-3 focal reducer and f/10, so you have more "magnifications" to work with.
Rod Wodaski's CCD Calculator will show you how the 8" SCT at different focal lengths and many other telescopes will frame various objects in the Mallincam. Link:
http://www.newastro.com/newastro/book_new/camera_app.asp
In the camera box, you can select "SAC-9", as it has the same specifications (752x582) and the same ccd chip (Sony ICX428/9) as the Mallincam.
Have you looked at the Mallincam Yahoo Groups photos section? Jack Huerkamp has some single frame captures using a six-inch refractor and an 8" SCT with f/3.3 focal reducer. My photos (Martin Hilario folder in photos) show processed images taken with an older mallincam with 80mm f/5 refractor and 10mm f/6 dobsonian. link:
Mallincam Yahoo Photos
http://tech.ph.groups.yahoo.com/group/mallincam/photos/browse/4733
The Mallincam provides roughly the same horizontal field of view as a 6.4mm eyepiece with a 50 deg. field of view. With such small field of view and high magnification, a focal reducer is highly recommended. When coupled to a focal reducer like the MFR-3 plus extension ring, the Mallincam acts like a 12.5mm eyepiece with 50 deg. field of view.
From my experience and many others with cameras like the mallincam, fast focal ratios (f/2 to f/5) seem to work the best, as the faster focal ratio would allow the Mallincam to capture good images with shorter exposure times and more field of view.
Personally, I have had excellent results with the Mallincam Pro Dob (an older mallincam) with a 10" tracking dobsonian and the 80mm f/5 achromatic refractor that is piggybacked on it. Both were utilized with a Vixen 0.6x focal reducer, so the effective focal ratio for both is around f/3.5. Alt-az Field rotation seems to be a nonissue, even at the 28 or 56-second settings of the Mallincam, as long as an object is well placed in the sky (eg. Preferably not at zenith or high up at the meridian). Chromatic aberration is also nonexsistant when I couple the Mallincam with the 80mm achromatic refractor, so even a short tube achromatic refractor will work great.
I highly recommend an 8-10" SCT, when coupled with an f/3.3 focal reducer or hyperstar (available at http://starizona.com/acb/hyperstar/whatis.aspx ). Hyperstar is a corrector that replaces the 8" SCT secondary mirror and transforms it into a dedicated 8" f/2.0 telescope (therefore only usable for astrophotograpy if you want a dedicated mallincam telescope). f/3.3 focal reducer has worked perfectly for me too with a 12" SCT I've used.
Celestron CPC 8" GOTO Telesccope
http://www.optcorp.com/product.aspx?pid=1-600-602-892-6393
F/3.3 Focal Reducer for SCTs
http://www.optcorp.com/product.aspx?pid=779
Otherwise, a good 4" f/5-f/7 refractor like the TV101/Orion 120ED plus MFR-3 focal reducer is very much an excellent choice for portability and ease of use. Any equatorial mount like the Orion Sky View Pro will suffice, especially since the Mallincam exposes at relatively short (2/7/14/28/56 second) intervals. Periodic error and field rotation will not affect a live view.
http://www.telescope.com/control/product/~category_id=refractors/~pcategory=telescopes/~product_id=24357
Also look at this 120mm f/5 rich field achromatic refractor: http://www.telescope.com/control/product/~category_id=optical_tube/~pcategory=telescopes/~product_id=09836;jsessionid=771C5F91857BD81CB726095504D2B07E.ivprod1
Looks great for mallincam use, especially with an UV/IR blocking filter to reduce the chromatic aberration. Maybe not good with eyepieces, as chromatic aberration and maybe coma will be pretty apparent. I'm not sure if this is what you want, but it's probably good for mallincam-only use.
One last recommendation is an f/4 newtonian like the Meade SN-8 on LXD75 goto mount but the mount and the OTA are quite heavy: http://www.optcorp.com/product.aspx?pid=3223
It's an excellent focal ratio and aperture for use with the mallincam though! The orion short focal ratio newtonians look like they would match well with mallincam. Coma does not seem to be much of a problem when using the Mallincam with short focal ratio newtonians like these because the FOV of the camera is small. The newtonians are so cheap, but they will work great for mallincam! (though the views through the apochromatic look better when using eyepieces)
Orion 4.5" f/4 reflector
http://www.telescope.com/control/product/~category_id=optical_tube/~pcategory=telescopes/~product_id=09974
All in all, I think that a good quality short focal length 4" apo or achro (plus MFR-3) or a portable 8" SCT (plus f/3.3 focal reducer and goto) and the mallincam, will be an excellent inheritance for your daughter and for generations to come. Mount, in my opinion, does not seem to matter so much, as long as it is reasonable quality or even alt-azimuth, due to the ability of the mallincam to take pictures very quickly (6 seconds to 56 seconds), unlike a dedicated CCD imager.
Martin H
On Dec 9, 2007 10:43 PM, Douglas Phillipson <douglas at intermind.net> wrote:
Phillip Krumpos wrote:
> I am planning to buy a new telescope. I want a telescope that will give me
> the ability to use the Mellincam.
>
> My daughter, Joanne, will eventually inherit the telescope, so the weight of
> the components will need to be considered. My "bad back" also makes weight
> an important factor.
>
> >From what I have read about astrophotography the most recommended telescope
> type is apochromatic refractor. It also appears that getting the right
> telescope mount is as important as getting the right telescope.
>
> However, from what I have been able to gather from the internet, people are
> using a very wide variety of telescopes and mounts with the Mellincam. With
> your experience with the Mellincam, I would like to get your opinion on what
> would be good system to fully utilize the Mellincam.
>
> Phil K.
>
Phil, the telescope you select is highly dependent on your available
funding. Also should you choose a refracting scope, you won't be able to
enjoy many objects through the eyepiece. Refractors just don't have
the aperture to see anything good, unless you buy a very large one which
costs big bucks. They are only really good for planets and splitting
double or triple stars, boring stuff in my book. A reflector is much
better. I bet you would enjoy a 8 inch Meade, similar to mine but
smaller to better accommodate your weight requirements. 8 inches is
large enough to enjoy the Messier objects but also large enough to add
the Mallincam for some really spectacular color images. If you buy
anything less than 8 inches, you will soon be very disappointed with it
and want a larger one. Then you will have to sell the smaller scope,
only getting 75% of the money back.
I also suggest the Mallincam because of its ease of use. If you buy a
regular CCD camera, you will be dealing with complicated setup, snapping
many images on a laptop, dark frames, doing image processing and stuff
like that. The Mallincam can do that but you don't have to, you can
just get video out of it like I do, and display the image on a small
inexpensive monitor.
I suggest a Meade 8 inch LX200R or a Celestron CPC 800 GPS. They are
both about 2,000 bucks.
Here are the links:
--------------------------------------------------------------------------------
Meade: http://www.scopecity.com/category.cfm
Select Brand = Meade,
Drive type = Computerized-GoTo
Mount type = Alt-Az
Scope Type = Schmidt-Cassegrain
Aperture = 8.00
--------------------------------------------------------------------------------
Celestron: http://www.celestron.com/c2/product.php?CatID=9&ProdID=33
Hope this helps.
Doug P
P.S. Please say hi to Joanne for me...
_______________________________________________
Sent via the Lvas mailing list Lvas at lvlug.org
Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
--------------------------------------------------------------------------
_______________________________________________
Sent via the Lvas mailing list Lvas at lvlug.org
Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
_______________________________________________
Sent via the Lvas mailing list Lvas at lvlug.org
Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
------------------------------------------------------------------------------
_______________________________________________
Sent via the Lvas mailing list Lvas at lvlug.org
Set options or unsubscribe at http://lvlug.org/mailman/listinfo/lvas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lvlug.org/pipermail/lvas/attachments/20071218/975a597d/attachment-0001.htm
More information about the Lvas
mailing list