Monday, January 21, 2013

Astrophotography revisited......CMOS and CCD imaging...OMG am I selling out?

What has gotten into me. Have I been bitten by the astrophotography bug? Seriously? I have been a visual observer for the longest time and used to scoff at taking snapshots at the sky. But then again I have had the occasional "dabble", or forays into the complex and crazy world of astrophotography. I remember my first time, around Halley Comet's 1986 return to our part of the neighbourhood. I purchased some Fujifilm ISO 400 film (yes we used to shoot using good old emulsion films!!!) and shot star trails, constellation portraits (I have a few and if I can find them, I will scan them and put them up here) and a comet piccy or two (I shot Hyakutake in 1996 from my then "not so light drenched" backyard!). My weapon of choice was my dad's old Nikkormat camera. I learn about the B setting, using a bulb and mounting the camera on a photo tripod. Exposure times had to be kept short to prevent photo fogging due to light pollution and also to prevent the stars from trailing. I shot constellation portraits every chance I got, including our then dark sky site, a cleared construction site close to my friends home. I remember us building a campfire :) That was in the mid to late 80's!


Since then technology has advanced by leaps and bound. Its now much easier to shoot the night sky with digital camera's. No more buying high ISO films and waiting to see if the shots I took came out right. Its amazing what one can do with a simple point and shoot these days (and it is getting better trust me!). For instance I have shot afocally (and without a special mount too) the moon and a lunar eclipse through my Orion StarBlast and my 10" f/5 with my old point and shoot Nikon. Being back in oz and under dark skies, I dabbled in more constellation portrait shots and "comet" photography when Comet McNaught and Comet Holmes made surprise visits to the inner solar system, with my Kodak P850 camera. This cam was ok for point and shoot but it was an older model with 5megapixel resolution, full manual controls and a highest ISO setting of ISO800. My newest and latest digital cam is the Kodak Z990. I chose this camera as it is a bridge camera, like my older Kodak, that has all the features I need, such as full manual controls (I can push the ISO all the way to ISO 6400), a 30x optical zoom for my nature photography shots, as well as Kodak's first backlit CMOS sensor (i.e. better low light performance). With this camera I have taken shots of the milky way from Pinos and done some afocal photography. But the one thing that has always eluded me was getting good planetary shots!



Seeing an opportunity to wet my feet in the world of planetary imaging, I jumped at a recent chance to purchase Orion's new "lower end" Orion StarShoot Solar System Color Imager, which was on sale. They were out of stock when I visited their Cupertino store during the Memorial Day weekend, so I called in and got it over the phone. Little did I know that it would be about a month before I would get the chance to try it out on the moon and on Saturn and Mars, due to the pesky "June Gloom" marine layer. The verdict.......the cam would not come to focus in my newtonian scopes (see previous post). Disheartened, I packed the cam up and returned it to Orion for a full refund (thank god for their excellent after sales service). It was then that I spied a used Meade DSI I cam for cheap. This imager is touted to be a great "beginner" DSO and planetary imager as it is intuitive to use, has a much more sensitive CCD chip. Since receiving it in the mail this last Monday, I have installed the Meade AutoSuite and Envisage software and have tried it on terrestrial objects. trying it on celestial bodies, I found out that I was faced with the same problem, not enough backfocus. It seems that for CMOS and CCD imagers to work with newtonians, one would have to have a very short focuser. You live and learn. Therefore there was probably nothing wrong with the Orion Imager. The problem was due to my scopes.



Fast forward to December (yup this article has been the making for the longest time), I am now a proud owner of a Celestron/Costco 102GT scope (see reviews and small scope shootout articles from November). I have had the Meade DSI out, coupled to this GOTO tracking refractor, a couple of times under light drenched skies. The DSI now focuses fine, but now I have other issues to deal with. Firstly, the FOV is tiny in the DSI, The FOV equates to a 6mm eyepiece in my refractor. All I can see is the capture screen of Envisage is small portions of the moon, an overexposed Jupiter (still have not gotten used to Envisage's controls....not used intuitive at all!) and M42 totally filling the screen. I obtained a 0.5x focal reducer from Orion over thanksgiving and it is only now in January that I got to give it a go. The focal reducer does make a big difference and I can now get some of the tighter star clusters in the FOV. Also upon exposure I can at least see what I am imaging. Here are some of my 'first shot' images. Hopefully more to come. You can see from the shots that I exposed it for longer than 30 seconds. Field rotation is a problem with my motorized alt az mount. Will try for shorter exposures 30 seconds and under and stack the images. Stay tuned, this page will be updated regularly with new images and notes!!!!


Old piccies. Afocal astrophotography with my Kodak Z990, Orion SkyScanner and Orion Steadypix camera adaptor (see photo above). Even with the adapter, it was hard to get the camera lens at the right position and distance from the eyepiece. I found that I could only shoot brighter objects, and with very short exposures with wide field long eye relieve eyepieces. I have since sold the adapter. Its just too hard to get the camera in the right position, and even then the heavy camera sometimes swings out of the way.


My playground observatory where I do most of my imaging. Notice how light polluted the playground is. It is actually worse than it looks since I can visually detect some pretty dim quarry such as M65/66 in Leo, the Little Dumbbell (M76), the Crab Nebula (M1) and the Owl Nebula (M97).


Celestron/Costco 102GT. For the price this combo can't be beat. Computerized guiding and tracking and with two star align, objects are pretty much centered in the FOV. The scope is seen with the Meade DSI I color CCD. Its a cheap way to get into the complex world of astrophotography. I know I will never be able to get pics such as the ones in Astronomy and Sky and Telescope, but for a little investment, I can capture some pretty keepsakes, as below.....


My first DSO image with the Meade DSI CCD camera....not bad huh since I have not even mastered how to properly work the cam with the Meade Envisage. The heart of the great nebula in Orion (M42).  5 minute exposure. You can see the effects of field rotation as the stars around the bottom have started to trail in an arc. Next time I will do stacking with multiple 30 second exposures.


This is a stack of several 30 second exposures and processed in Photoshop using curves. My focusing might have been off (or it might have been the tracking acting up...batteries are old and might need replacing) as the stars really looked bloated, but the nebula was heaps brighter. You can see the ruddy hues in the outer wings an well as M43. I have seen such rusty hues visually in my 10", but only from dark sky sites. And this is with a waxing moon that is past first quarter!!!!


Open clusters are easy provided you do not expose it for too long. Field rotation is a big problem with motorized alt az mounts that do not have an equatorial feature. This was a 3 minute exposure of the double cluster in Perseus (NGC 884 and 869). Tracking seemed to be pretty spot on as the stars did not trail. Even with the 0.5x focal reducer (taking the focal length down to 500mm), I still could not fit both clusters in the FOV.


NGC 2393, the Eskimo Nebula in Gemini. This one was easy to image as it is bright and starlike. I exposed it for about 3 minutes. Skyfog was crummy (bad part of the sky). I should have stacked the image and do dark frames. Next time perhaps.


Short 20 second exposure multiple stack of the Eskimo. The background was noticeably darker. I am surprised that the hot pixel problem is not much of a, well "problem". I cropped and color corrected the image in Photoshop.


A much better M35. Stack of 6x15 second exposures with Envisage. I find that 20 seconds is the max I can go on my GOTO alt az before the stars start trailing. Image processed in Photoshop using Levels.


M36 in Auriga. Again with Meade Envisage 6x15 seconds. Its funny how the sky fog is different with different parts of the sky. Also I think the dimmer the object, the worse the color balance is thrown off. Processed in Photoshop with Levels and Color Balance.


M37 in Auriga. Again 6x15 second exposure. Similar part of the sky so sky fog was a problem. Processed with Phoptoshop Levels and Color Balance.


M38 in Auriga. 6x15 second exposure. Again skyfog was a big problem. I think I might have to resort to some sort of broadband filter for imaging, even open clusters. I am happy though with my results. Can't wait for summer to come around. Bring on M57, M27, M13, M5, M22, M8, M20, M17...OMG the list goes on and on...till then enjoy my galaxy pics....


M81, Bode's Galaxy in Ursa Major. My second imaged galaxy so I am a happy camper. Captured using Meade Envisage with a 6x15 second exposure and processed with Adobe Photoshop Levels and color corrected using Color Balance function.


I still can't believe I got this...my first galaxy M82...and it was visible at the screen...more visible than through the eyepiece!. Exposure was 6x15 second with Meade Envisage and processed with Photoshop and color balanced with Color Balance function.


My forays into the complex world of astrophotography continues. I am learning something new about my Celestron Nexstar/Costco 102GT everyday, such as how it tracks better in some parts of the sky than others. I am also learning the intricacies of my first CCD camera, the Meade DSI 1 color one shot camera. Things that you cannot see on screen may be in the FOV. You just have to do a quick preview. I am also discovering the joys of imaging galaxies from suburbia. Its much easier than I though...maybe its because I have been imaging the brighter and more compact galaxies. Take the Sombrero Galaxy in Corvus/Virgo for instance. This is a 12x10sec stack of M104. My color balance is always off (more towards the reds) and I am attributing that to the local light pollution. So much so I have to do a color correction within Photoshop everytime I process my shots. But I captured the dust lane! Isn't it wonderful what technology can do these days...and for so little money at that. My next trial is to use my SkyGlow filter to see if I can improve on the background light pollution. Stay tuned...


Experiments with Stark Lab's Nebulosity. Its funny how much sharper the image is with Nebulosity. I am trialling the software and it is useble with my MacBookPro, which means heaps more imaging time (my Mac last up to 5 hours while the damn HP lappy a mere 1 hour!!). 17 second exposure no stacking and no dark frames and processed with Photoshop Levels.


More M42 with Stark's Nebulosity for Mac. I am using the older version (not version 3 as my OSX 10.5 does not support the latest version. The problem with the demo version is that if you do use stacking, you get vertical lines across the piccy. I used the preview to capture this image. I find that trailing is a problem after 20 seconds of exposure. The demo version is fully functional and is heaps more user intuitive than the Meade Envisage capture software.

UPDATE (1st of Feb 2013): I am still experimenting with both capture software, Meade's Envisage and Stark Lab's Nebulosity for Mac. Pro's and con's for both. Stark Lab's Nebulosity gives much cleaner images and better contrast (and tighter star images) but to me it is less sensitive. maybe I am not getting the setting's down right but at this point I am still leaning towards Meade's Envisage. Its just easier with the live view and somehow more sensitive views, making it easier to "see" your target. More to come....

UPDATE (9th of Feb 2013): I have reverted to using Meade's Envisage. Its just easier to use and more sensitive. I can't for the life of me figure out how to get a "visible" image in Nebulosity and this is a problem when imaging fainter fare!

Monday, January 14, 2013

Battle of the lightweights...Orion Spaceprobe versus Orion Funscope

I told you I had a problem. You just wouldn't listen lol. Hahahaha yes I admit it, I am a small scope shootout addict!!!!!! Being here where scopes are so darn cheap does not help me at all.  I need help.....hopefully in a good way. The contenders this time were the Orion Spaceprobe 3 and the Orion FunScope tabletop, astride my Orion Paragon HDF2 photo tripod. Both scopes have 76mm spherical primaries (300mm f/3.9). One has a long focal length and almost diffraction limited optics (700mm f/9.2). The other contender is a lightweight tabletop "grab and go" scope (in my opinion even the SpaceProbe is grab and go as it is so darn light). I pulled this shootout off from my light drenched playground observing site. I was having so much fun with my Celestron/Vixen C6 on Portamount that I decided to do this after my 2 hour session. Again I tried to match up the magnification, which wasn't hard seeing that the Funscope had about half the focal length of its longer tube brethren. I looked at all objects with my 24.5mm Meade SWA ep and 2x Orion Shorty Plus barlow (used this in the Funscope to correct for its annoying coma and off axis aberrations) and the stock 25mm Explorer II eyepiece that came with the Spaceprobe. Objects to be scrutinized included the waning quarter moon, Jupiter, M42; the Orion Nebula, M45; The Pleiades, the Perseus double cluster as well as Auriga's open clusters (M36, 38 and 37). Here are my findings:



Waning Quarter Moon: SpaceProbe clear winner. Absorbed magnification like a sponge. Very sharp contrasty view...blacks were black. The Funscope could not keep up. Images begin to soften over 50x magnification. Even with the barlow, only the inner 2/3rd of the FOV was sharp. Also the views were considerablly "mushier" than the Spaceprobe.

Jupiter: No contest. The Spaceprobe continues to astonish me with its high contrast and super sharp planetary views. This is as good as it gets for a scope of this aperture. The Funscope clearly is not a solar system scope. While it is capable of showing Jupiter's disc and moons, it threw up an annoying halo (or haze???) around the planet at high magnification (above 50x). I had this same problem with my Celestron Firstscope mini dob. I could make out Jove's two equatorial belts, but nothing more. By contrast, I could make out festoon's and other minute detail when the seeing steadied with the Spaceprobe.

M42: Both scopes gave great bright views. I expected this as they have the same aperture. Views were almost indistinguishable save off axis where the seagulls started to plague the Funscope. I noted thought that the Spaceprobe stars were more "pinpoint" than the Funscope. Achieving focus was way easier in the Spaceprobe too.

M45: Same bright views but the winner would have to be the Spaceprobe for its flatness of FOV and lack of aberration. The coma was really distracting in the Funscope, and while the views were great, I preferred the Spaceprobe's views.

Open clusters Perseus double cluster, Auriga clusters (M36, 38, 37): Again both scopes threw up similar bright views, but coma and off axis aberrations spoilt the views for me in the Funscope. I think if I were to use the Funscope by itself and not make it go head to head with a longer focal length scope, I would have enjoyed the views.

So here is my take on things, the Funscope by itself really is a Funscope. Its light, its cheap, its fully equip from the get go, as it comes with Orion's three element eyepieces (20mm and 10mm, much better than the crap Huygen's that come with the Celestron Firstscope) and an Orion red dot EzFinder sighting scope. You do not need to buy anything else to get you started. Also another plus it has over the Celestron model is that it has a tripod bushing and can be mounted on standard photo tripods, so you never need to worry about not having a park bench to rest the scope on. That in itself is worth the price of admission. The Celestron, while cheaper, comes with ridiculous eyepieces, no finder, and no tripod bushing. Optics wise, I found both the Celestron Firstscope and the Funscope indistinguishable. Well they were both probably made in the same factory in China.

Would I recommend this scope for a firstscope? Unfortunately I would say no, unless it is a gift to a very young child who is just getting his/her's feet wet (and because its so cheap, it is okay if the child destroys the scope ;) or a second travel scope for a season stargazer. Again most beginner's want great views of solar system objects. Due to its very short focal length spherical mirror, this scope is just incapable of doing this, with its best views at 50x and below. This scope is best for low magnification panning of the milky way under dark skies PERIOD.



Again for a firstscope, you can't go wrong with the Spaceprobe 3. It has everything the Funscope has (similar three element eyepieces and a Orion EzFinder), plus a near diffraction limited mirror for sharp and contrasty solar system views. call me impartial, but I just love the SpaceProbe. I would even go as far as to recommend this scope over, say the Orion SkyScanner, which incidentally retails for about the same price to young beginner astronomers due to the very fact that it is just a very good scope for sharp high powered views.

Next up.....how to make suburban stargazing fun again...coming to a galaxy near you!

Wednesday, January 2, 2013

Small scope shootout.....it is becoming a habit



Hahaha as the title says I think I have a problem. I like small scopes and I love doing shootouts. Maybe it all stemmed from my love of testing out equipment and the joys of using simple uncomplicated scopes. I, for one, have always been an advocate of the KISS principle, be it in life, work and hobbies. All my scopes are easy to use. I did away with my EQ mount when I got the chance (and even when I was using the EQ mount, I would use it in alt-az mode!). The closest I have gotten to a semi complicated "scope" is my Celestron NexStar 102GT, but even then it is not that difficult to use. All my other scopes are mounted on either alt-az mounts or dobsonian mounts. Simple easy and effective. Just carry it out, downstairs or whatever, plop it on the lawn and away you go. No messing around with setting circles, polar aligning and all that mystical mumbo jumbo.



Which brings me to my small scopes. I love small scopes. They may not give you the deepest views of deep sky, or the brightest views under light drenched skies. But what they lack in size, they more than make up for it in heart. Also they literally scream at you to use them when the night is dark and clear, even when you are super tired after a days work! I have seen my fair share of small scopes over the years. Hell I started with a scope some people would scoff at, my Celestron Cometron CO40 (40mm f/20 refractor from a bygone era), but I persevered and look where I am today! Scopes I have gone through include my Cometron CO40 (which I still have!), a couple of 60mm scopes (both long (Kasai orange tube f/5) and short focal lengths (Cometron CO60, Meade 60mm, and one dud Japanese 60mm f/11, a 70mm scope (Celestron Powerseeker), 76mm reflectors (two f/9.3's, a blue tubed Explorer and a Orion Spaceprobe 3, featured here and two f/4's, a Celestron Firstscope and an Orion Funscope), a 80mm Orion ST, a 90mm "dud" ST, my Orion SkyScanner  reflector 100mm (featured here in the shootout), two 102mm refractors (my Celestron NexStar 102GT and a Synta blue tubed f/5) and three 4.5" reflectors (Meade 114mm bird-jones OTA and two Orion StarBlast (a dob and a imaging OTA). I don't regard anything above 4.5" as small so I have excluded my Celestron/Vixen C6 and the Celestron Powerseeker 127mm reflector. So yes I love small scopes.



So why shootouts. Shootouts are good as I love visual observing and I also like to push my scopes to their theoretical limit, both in terms of deep sky and also lunar and planetary. I generally find that if a scope somehow lacks optically, then everything else suffers. If I am going to be dealing with smaller apertures, I want the scopes to perform as well as they can be for their given aperture. Also shootouts brings out the deficiencies in scopes that otherwise would go unnoticed. Plus it is so much fun putting scopes head to head. So who are the contenders tonight? Well well seeing how well the Orion Spaceprobe 3 performed the last time it went head to head with a 70mm refractor, I though I would put it side by side with one of my current most used scopes, my Orion SkyScanner 100mm. The SkyScanner is a great scope and a terrific value (even though it has gone up in price and it is not as cheap as it is used to be). It comes with everything right out of the box, effective eyepieces, a good red dot finder and a totally robust mini one arm dobsonian mount! All one needs is a sturdy table or a stable photo tripod. I usually use mine on my Orion Paragon HDF2 mount. It is the perfect grab and go setup as everything can be carried with one hand, and it breaks down into smaller pieces for travel.



Now the Spaceprobe 3. While it may not be as small when broken down, it is still plenty portable, Just collapse the tripod after removing the triangular accesssory tray and you are good to go. Plus it is so light it can be carried with one hand. Orion even sells a carry bag for it, although I think you have to seperate the tripod from the OTA, which is annoying as there are no captive screws. I just carry the whole thing and plop in in the back of my car/van. So yes I can carry both scopes, down two flights of stairs and into my playground observatory in suburbia...easy peasy no probs. selecting objects for the shootout was easy too since it is winter and there are so many bright DSO's that are visible from light polluted skies! I chose similar objects from the last shootout, and threw some new ones in too. Here is my breakdown and verdict:

  • M42, the Orion Nebula: an obvious test. Views with the Spaceprobe was again very contrasty. Nice dark velvety skies made the nebula stand out. The SkyScanner's background was noticeably greyer, even with the NPB filter in place.....BUT, the SkyScanner went deeper, revealing more of the outer wings than the SpaceProbe. Although I liked the views in the SpaceProbe, I prefered the image the SkyScanner threw up. +1 SkyScanner.
  • M78, reflection nebula in Orion: this a harder one as it is moderately faint under light polluted skies. Still it is doable. M78 was visible in the SkyScanner wihout much effort. My notes read faint though. Still once I found it, I could hold it. This was not the case for the SpaceProbe. Much harder to hold, needed the OTA to be tapped and jiggled to be visible with averted vision. Notes read borderline visible. +1 SkyScanner.
  • M45, the Pleiades cluster: Both threw up great bright views that were not very different in appearance. I prefered the view in the SpaceProbe due to its better contrast and flatter field (i.e. next to no coma). Coma was annoying in the SkyScanner, even after I used my better eyepieces, which improved the views. +1 SpaceProbe.
  • Perseus double cluster: Both scope gave great views. Again the flatter FOV of the SpaceProbe gave a more aestetically pleasing view. However more of its dimmer suns were visible with the SkyScanner, even with coma. I preferred the deeper views offered up by the SkyScanner. +1 SkyScanner.
  • Auriga Clusters M36, 38, 37: Same as above. Better shallow contrasty views in the SpaceProbe, but more stars visible with the SkyScanner. Preffered view SkyScanner. +1 SkyScanner.
  • M31, the Andromeda Galaxy: Since the great galaxy was lower in the skies, the views weren't the best. But I had to have a galaxy in the field testing  for completeness. Again contrast was great in the SpaceProbe, BUT the SkyScanner just went deeper and M32 was easier to see, and the core of M31 was visibly brighter. +1 for the SkyScanner.
  • Jupiter: The SpaceProbe beat the pants off the SkyScanner in this respect. No contest at all. High power images fell down above 100x for the SkyScanner, but the SpaceProbe just keep on soaking in the power. Very nice contrasty views of Jupiter and abundant detail in the belts at high mag when the seeing steadied. I am still amazed how much detail there is to see on Jupiter with this scope. +1 SpaceProbe.
  • The waxing moon: Again the SpaceProbe kicked ass, as in SkyScanner ass. No contest here. The terminator region was a nice neutral color and the shadows were razor sharp and dark! Again high power was a non issue for the SpaceProbe. +1 SpaceProbe.

And the verdict, while I liked the SpaceProbe, if I had to choose just the one grab and go scope, I will still go for my SkyScanner. Its just goes deeper for deep sky, which is my fave past time (and the views are visibly brighter for most DSO's I looked at). I love looking at the moon and the planets, don't get me wrong. But there are heaps more to see with a bigger aperture and deep sky. I hate coma, but I have come to live with it, as all my scopes are fast scopes, and I have eyepieces that can deal with this, to some extent. When it comes to contrast, I guess I could flock my SkyScanner at some stage. It would probably still not look as contrasty as the SpaceProbe since the mirror is a hell lot closer to the mouth of the OTA. One thing to note though, I love the SpaceProbe mount. It is just so stable and easy to use, even more so than my dob mount. As I mentioned in my previous shootout, this mount is a joy to use. For instance I timed the mount and how long its damping time was. Took a whole 3 seconds after a sharp rap. By contrast, my SkyScanner on the Paragon mount took longer to settle. Will have to try the dob mount a picnic table the next time.



So yes we have come to the end of another epic showdown. depending on your observing habits, you could go either way. I am a dyed in the wool deep sky fanatic and would take bright deep sky views over super clear and contrasty views of solar system objects anyday. Your  preference might differ. that's what makes our hobby so special. Everyone is different. You make the choice......