Anand Raj's ASTROPHOTOGRAPHY Corner
MY PERSONAL THOUGHTS ABOUT ASTRONOMICAL TELESCOPES FOR PHOTOGRAPHY
Astro-Physics 105mm f/5.9 Traveler:
One of the best portable 4" apochromatic refractor in the whole world!
This is one of my favorite scopes, and the one I use the most often. The optics are incredibly sharp and the focus snap is like nothing I've ever experienced. There is no discernable color fringing and cool down times are negligible. The FeatherTouch dual speed focuser is a joy to use-smooth and no elastic play. The 2.7" focuser can handle both 1&1/4" and 2" accessories, and with a focal reducer, one gets f/4.5! I've not compared the optical performance of the Traveler to the Tak FS-102, but it left my Tak Sky 90II face in the mud. While the aperture difference made it an unfair comparision, there was no question which was the superior scope optically.
The Traveler is my workhorse scope and I use it for visual and photography and it brings me immeasurable joy. After all, this is what truly matters- using a scope, using it often, and enjoying it immensely.
The build quality of the Traveler is second to none. Rapping on the OTA feels like rapping on tank armour. I figure the design intent of A-P was for the scope to be taken all corners of the earth and be able to withstand the banging around of train rides, safari romps and rough baggage handling. A Takahashi feels down right delicate next to the Traveler. The aesthetics and functionality are impeccable. All parts are well machined and accessory support is logical and well laidout. I like the sliding dew shield ( a departure from its bigger 130 and 155 EDF/EDT siblings). In addition, I like not struggling with confusing and expensive adapter parts like a typical Takahashi. The front objective of this oil-spaced tripet is deep magenta in the outdoors, potenting the richness and quality of the optical coatings applied.
It is always good to over-mount a scope than under-mount for astrophotography so you have an ultra-stable imaging platform. When mounted onto my Takahashi EM-200, the setup is virtually wind proof and ultra stable. OR better yet, the Astro-Physics Mach1GTO is an absolutely outstanding mount for scopes in this weight class and it even more stable than the EM-200. For quick look-sees, I use the scope on a Discmount DM-6 with an A-P Wood Tripod. The combo is outrageously stable.
I frequently use this scope for astrophotography as I find that the images are extremely sharp. However, I wish there was a rotating focuser option for the Traveler like a Takahashi camera angle adjuster. I have recently purchased a used prime focus field flattener and I will be trying that out soon. The prime focus field flattener indeed has a feature that allows you to rotate and frame your camera shot, and that is a welcomed convenience. In the future, I am hoping to acquire a mid-range SBIG camera, and hence the curved focal plane will be less of an issue due to the smaller imaging chips and FOV of these cameras.
Under dark skies, this scope excels at giving you wide field views. With a 35mm Panoptic, you can see both sections of the veil, and the richness of the North American Nebula. Although the short focal length makes double star and planetary observation trickier, when used with my short focal length Radians, this scope gives nothing up. Focus snap is resolute and color is true. There is no play in focusing- it just snaps in.
The Traveler is a very portable scope. Although I've not taken it on a plane, I've certainly taken it everywhere in my car. There is always lots of space left for stuff in the trunk!
Astro-Physics 130 EDFS f/6: Most portable 5" Apochromat in the (used) market!
Here is another beauty from Astro-Physics! Going from a 4" to a 5" refractor was a big shock to me. The 5" is so much bigger and requires more care in handling. You have to watch carefully when navigating doors and entry ways with this scope cradled in your arms. Yet, having said all that, this 5" scope is very light, weighing in at approximately 14lbs. I had originally considered acquiring a Takahashi TOA-130 but decided not to based on the weight. While the Traveler has a tangible muscular feel, the 130 has a more sveltepersonality to it. Fully loaded with rings, SBIG STV, Canon 20D and all, my A-P 130 comes in less than 25 lbs. A TOA-130 with a correspondingly similar setup would be above 30lb. As I wanted to maximize mount stability due to the fact that my site is prone to wind, the A-P 130 was the natural choice due to its compact length and light weight. All in all, the AP 130 is a wonderful OTA for deep sky photography. I love using this scope!
It took a month or two to get use to this scope but now I really enjoy using it. The superb contrast of this scope compensates for its small aperture. On steady nights you can very easily see the trapezium E and F stars. Under dark skies, M42 swirls with wild unimaginable tendrils like torn silk billowing in the wind. Cassini's division on Saturn has extremely high contrast, and the color-free optics allows the presentation of tonal and color gradations on the surface of the gas giants in the most visually pleasing manner. When examining the moon, there is no discernable trace of false color on the limbs, at least to my 40 yr old eyes. Double stars are a pure joy. This scope has no vices to speak of and it gets down to business in a hurry with little fuss. I also have to add that I have found A-P a receptive and accessible company. There had been times that I have had to call and write with questions and Mr. Christen has always gotten back to me and addressed whatever issues I've had. There are not many companies that offer this level of service, and there are not many companies like this where ethical and fair values translate into the conduct of business. Photo of moon taken with A-P 130mm @f/6.
The updated 130GT is similar to its older sibling but the sliding dew shield sure is a big improvement and is one less expensive thing to drop in the dark. The new GT version can be broken down into three sections for airline transportability. I've never tried that...packing a big tube, delicate lens elements and a focuser, together with a mount, tripod and observing accessories is too daunting a thought for my lazy bones.
Astro-Physics Stowaway 90mm
They say in the good book that it is a sin to covet, but golly gee almighty I've wanted this scope for many years and finally found a used one. It certainly lived up to its reputation- incredible optics, light weight, excellent contrast...everything. The only thing to speak against is that teensy dew shield that extends modestly. One look through this scope will make you lust for one, and in the words of Alan Greenspan, spark off "irrational exuberance".
Takahashi FS-102 f/8.2
My first scope after a long hiatus from Astronomy! Many years ago I purchased a Vixen Fluorite 4", and I remembered being absolutely stunned when I first pointed it at Jupiter. It was absolutely tack sharp. From that point onward, I've always been partial towards apochromatic refractors. Hence my return to Astronomy in '03 quickly took me down the refractor path. The Takahashi FS-102 is a well constructed OTA with a silky smooth focuser. The paint is milky smooth white and a beautiful blue margin rings the lens hood (which is not retractable). the scopeis light weight enough to be carried on a Vixen GP or GP-DX mount (although the old Vixen HAL aluminum tripod really sucks at stability), although itslong length makes it prone to winds. I would recommend a Takahashi EM-200 for this scope as a rock steady alternative. The rare no longer made reducer cuts the focal length down to f/5.9 and makes it a great astrophotography instrument (although its cousin the FSQ-106N is a better choice).
The 1.25" compression ring supplied will hold heavy premium eyepieces and diagonals, but I would highly recommend the CAA (Camera Angle Adjuster) for visual observation as it sure beats the inconvenience of having to constantly mess with the compression ring to adjust the diagonal position. For this telescope, I also recommend the Takahashi 7x50 finder over the 6x30 finder. The 7x50 finder is fabulous and bright, while the 6x30 is quite limited for the urban night skies. Compared to the Feathertouch focusers on A-P scopes, I found the Tak MEF 10:1 fine focuser a little less pleasing. There was sponginess in fine focus and you really had to know where to tweak it to your liking.
What I find challenging about the Takahashi system is the complexity and high cost of the accessories. Extension tubes and the like seemed unnecessarily high priced. AlpineAstro sells some Takahashi-compatible accessories that are high quality and economical.
All in all, this is an enjoyable scope and I will have no hesitations in recommending this to anyone. A used FS-102 will be quite a find. I did my Messier catalog on this scope and it was fun picking out all the clusters, nebulas and galaxies. Under dark skies this scope really shines, while at home in my backyard, I've enjoyed many double stars due to its nice long focal length. I sold mine when I acquired the A-P Traveler but it was a hard decision!
Takahashi Sky 90 II f/5.6
You won't believe how small this scope is when all packed up in its Tenba bag. No way this is going to be a 90mm! It just folds up to the size of a subway sandwich! What a "cute" little guy this is, and what a great performer, with every bit the blood of its bigger brothers in its veins. Optics are fantastic, although mine arrived out of collimation and had to be returned to Texas Nautical. With the reducer, wide field photography is possible with a 35mm DSLR. I used this scope primarily for astrophotography, and rarely for visual observation as I had bigger scopes and scopes with greater focal length. But for the few times I did I enjoyed the wide field views very much. Takahashi recommends the Extender-Q as a better way of extending the focal length for higher magnifications, and that is suppose to remove all trace of false color. In the photo, you can see the Tak 90 with a Vixen 60mm guidescope and the 7x50mm finder, all attached on my Universal Astronomics MicroStar. A little over the top, yes, but still very functional! My complaint? Man, I really hate all those goofy confusing accessories that you need a Ph.D. to mess around with, and God forbid you need to buy extension tubes- they are $45 each and I needed two of them!
If you do DSLR astrophtography, this scope will give you incredibly wide views when you employ the flattener/reducer. The f/r is very well made and corrected, and stars appear pin point to the edge of my APS-sized imaging chip. Good job there, Takahashi!
Takahashi FSQ 85ED "Baby Q"
Who says the Japanese are so staid as to not enjoy a bit of nerdy humour by calling the smallest of the FSQ astrographs the Baby Q. It's certainly a cute scope, and at 85mm, surprisingly hefty compared to a Televue 85 or Astro-Physics Stowaway. It's a quad system with good optical flatness, correction and works both visually and coupled to a DSLR. The rotating focuser is certainly helpful. I use this scope visually, for astro-photography and occasionally even for portrait work. It's a great, great scope and certainly worthy of the Takahashi lineage and badge.
Televue 60mm APO
By now you might have formed the impression that I am a refractor kind of guy, well, you're sort of correct there, although I do have a Celestron C9.25" which I will highlight next! But, back to refractors. The Televue 60mm APO is am amazing scope. I use it as a finder, a bird watching scope, a guide scope for my SBIG STV and as a astronomical scope when I travel. Optics are tack sharp, absolutely no trace of color. I simply can't find much to be unhappy with this little guy. A highly recommended buy! In December of 2005, I took this scope to Singapore. It was a great choice, even the Tak 90 would have been a little too big, considering I was traveling with two small children. I took a 3mm Radian, 9mm T6 and a 24mm WF, and I enjoyed many nights examining the Southern skies. This scope takes power very well, and one morning I found myself enjoying the cloud belts of Jupiter with my 3mm Radian. I could see the delicate beige and browns that defined the belt system of the planet. I call this scope a poor man's Canon "L" lens. It is tack sharp and great for birding. See my review on Astromart: http://www.astromart.com/articles/article.asp?article_id=291 .
Televue TV-76 and TV-85
The TV-76 is a great improvement over the TV 60 in terms of brightness, resolution and ability to soak up a little more magnification. It is still highly portable and travelled to Singapore and back to Charlotte as a hand held without once being opened for inspection. The TV-85 is quite a bit longer and I am wondering if some airlines may insisits on it being checked in at the gateside- that would be quite disastrous. Overall, these two scopes are wonderful APO performers. There is quite a bit of color out of focus but in-focus images are sharp as tack, and they are able to soak up a serious bit of magnification.- a testimony to the optical perfection of the Televue scopes. The TV-76 will not come into focuse when using the 1 1/4 Everbrite diagonal with Radians- I needed to use my AP 2" Maxbright. The TV-85 will. The TV-76 can be supported by the Microstar alt az mount, making the setup ultra portable, but it tends to be a little tail heavy due to the short tube and the attachement point. The TV-85 is longer and better balanced but it might be over the top with the Microstar unless used at lower magnification powers. There is a perceptible brightness increase between the 76 and 85, and I can easily see Antares' green companion with the TV-85 while I have not really tried with the 76. So consider your purchase choice carefully and balance factors such as weight, portability, and cost. Photo below shows the TV-76 in binoviewer mode.
Celestron C9.25" XLT
"Sexy" is not the first word that pops into one's mind. Nor "cute". Try "water heater from a Soviet-era housing complex". But it sure is a great performing scope- when all the stars are in line! First, cool down is important. Images are cruddy before cool down and beautiful after the scope is cooled down. What this means is preparation for viewing and no spur-of-the-moment stuff. Then, you need steady skies to avoid looking at star images like a bunch of jiggly beans. Next, the correcter element is prone to dewing and has to be protected with dew heaters, but one has to be careful not to overdo it by introducing image-degrading heat. Then you have collimation- absolutely important and not to be ignored. Then you have stability. Believe it or not, at very high magnifications (such as for webcamming) the EM-200 is not quite enough! But for normal viewing it is. On a DM-6 this scope is rock solid, even more than the EM-200! Forget about the Vixen stuff or the Chinese stuff. Not even worth a thought. So how does it perform when under optimal conditions? Amazing. Makes you wonder why you need an APO refractor. But then, remember these moments are pretty rare, as you need a confluence of all the above mentioned factors to achieve the "wow!" state. Most of the time, atmospheric instability makes it hard to realize the full potential of this scope. Still, a very competent scope with great optics and an equally fantastically affordable price tag!
Astro-Physics 140mm f/7.5 Ren Ai Group is one of the top singapore recruitment firm , human resource shared services , employment pass application , payroll outsourcing singapore .
Celestron Ultima 8"- very nice, well built. Optics are great. Solid. Wished I had not sold that thing! I am surprise these do not show up on Astromart that often.