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Canadian Telescopes 152 F-5.9 Acromatic Refractor

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#1 Olivier Biot

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Posted 13 November 2011 - 05:26 PM

CT152 F-5.9 Acromatic Refractor from Canadian Telescopes​.com

By Warren Maguire.

#2 Russ S.

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Posted 14 November 2011 - 06:37 PM

Warren - Curious why you chose the 3" focuser over the 2", what are the benefits or advantages?

Thanks,
Russ

#3 WarrenM

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Posted 16 November 2011 - 02:53 PM

Russ: To answer your question the 3" focuser has two advantages over the 2" focuser that I wanted. The larger diameter draw tube allows the focuser to be racked in farther into the telescope with out intercepting the light cone comming from the objective lens. The draw tube on my telescope is 4" long and will bring any eyepiece to focus, including a bino-viewer. The 2" draw tube is much shorter and requires an extension tube to be added to bring some eyepieces to focus. The 2nd advantage is payload capacity. the 3" has an 8.8 pound capacity. The 2" has around a 4.5 pound capacity. There is one other factor. Appearence. The 3" focuser looks great on this scope!! Warren

#4 geminijk

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Posted 18 November 2011 - 05:55 PM

Warren,

Love that review. Thing looks very big for a 6", really much bigger then the 102 on top, I initially thought it was a 80mm. Enjoy that beautiful scope!

John

#5 WarrenM

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Posted 18 November 2011 - 07:05 PM

John: Thanks for the kind words. I'm glad you liked the review. Since submitting the review in July (C.N. took almost 4 months to publish it!) I have used the scope many times and I'm really happy with it. Warren

#6 Rich

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Posted 19 November 2011 - 01:36 AM

Warren,
Enjoyed your review and pictures. I'd love to hear more observing experiences, especially what you've found in terms of wide field views with this scope. Planets are always interesting, however I'd think this scope's forte will be the wide fields we usually only see in smaller scopes (like your 102), and with 6" of light gathering it must be a great rich field scope? It has the same focal length as my 100mm ED, but something like double the light gathering, so it intrigues me.
Thanks,
Rich

#7 WarrenM

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Posted 19 November 2011 - 05:55 PM

Rich: Glad you liked the review. Your question about wide field views with this scope is well taken. I've seen some amazing sights with it that are impossible with my Meade 10" S.C. My Meade 40mm SW eyepiece produces a big 3 deg field at 23 power which allows me to view big open clusters like the Pleiades and the Beehive. Both of these clusters are a nice sight in my 102, but in the CT152 they are breathtaking! Along with the brighter stars in these clusters are dozens of fainter stars which are not visible in smaller scopes. The wide field gives a wounderful 3D impression of the clusters floating in space. Another nice use for the low power/wide field is to compress difuse objects to increase surface brightness. This works especially well with M31. Though smaller it seems just as bright as my 10" S.C. shows it at 63 power. I've also seen M81, M82 and NGC2976 all in the same field for the first time. My 102 doesn't show NGC2976 but the 6" does. For a real treat I just randomly point the scope at the Milky Way with the 40mm SW. What a sight! It seems like thousands of tiny pin point stars are visible! I hope this gives you a better idea of this scopes wide field performance. Warren

#8 Rich

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Posted 20 November 2011 - 03:43 AM

Warren,
Good stuff, thanks for reporting your experiences.

#9 amirab1

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Posted 21 November 2011 - 10:14 AM

Hi Warren

Enjoyed your report.
What is your experiance with splitting double stars using high magnification especialy with an hige magnitude primery - is there a significant CA?

Looks like a fine scope.

#10 WarrenM

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Posted 21 November 2011 - 04:15 PM

Hello Amir
I don't have a complete answer for your question yet. Before getting the CT152 I only had a passing interest in double stars. I recently bought The Cambridge Double Star Atlas so I can get more into viewing them next Spring and Summer. I can tell you that viewing the popular doubles like Albireo, Cor Caroli, Mizar, the Double-Double, etc. there is vertually no CA, except for Mizar. At 2.2 mag it did show a little CA, but when I used my Baader Fringe Killer filter on Mizar the CA did not show. When viewing very bright stars such as Vega, Altair, Arcturus and the planet Jupiter, the CA is fairley significant. Using the Baader filter gets rid of about 50 to 60 percent of the CA. I made an aperture mask 4.5 inches in diameter to see what effect it would have. The mask effectively makes the scope into an F-8. By using the mask and the Baader filter together I got very good results. The CA on the bright stars was cut by 90 percent or more and on Jupiter I coudn't see any CA! In the future when trying to split a close double with a bright primary I'm probably going to have to use the mask and filter. I hope this gives you a better idea of this scopes CA issues. Warren

#11 mattyfatz

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Posted 21 November 2011 - 09:47 PM

Warren,
I really enjoyed your article. I have been eyeballing the AT (hands on optics) version for a while now. I am a big fan of big wide field views of DSO's. I have been smitten with the ES152 for some time as well, but your review as well as other comments have led me in this direction. Thank you for all of the great photo's as well.
-Matt

#12 WarrenM

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Posted 22 November 2011 - 12:21 AM

Matt:
I really enjoyed reading your comments. You sound just like me! When I decided to buy a short focus 6" acromatic refractor it was the Explore Scientific AR152 that I was considering. But then I came across two reviews that changed my mind. Scopereviews.com has a head to head review (by Ed Ting) of the AT152 and the Exp. Sci. AR152, complete with pictures of both scopes side by side. If you haven't read this review go to their website, on the home page scroll down to review #P-26 and click on it. The review that finally sold me on this scope was Larry Carlino's review of the AT152 on this website. When I discovered that Canadiantelescopes.com was selling the same scope (as the CT152) with the 3" focuser I couldn't resist. I don't think you can go wrong with any of these scopes. It's just a matter of how much you want to spend.
Warren

#13 mattyfatz

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Posted 22 November 2011 - 03:04 PM

Thanks for the info! :tomatodance:

#14 AllanF

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Posted 05 December 2011 - 10:56 PM

Warren:

Just wondering if you are happy with the Celestron CG5-GT mount? I am guessing that the advertised 35# payload capacity has a decent safety factor.

#15 WarrenM

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Posted 06 December 2011 - 05:41 PM

Al:
The short answer to your question is yes, I am happy with the CG5-GT mount. But there were problems that had to be solved before I was satisfied. One of the problems (mentioned in my review) is the Vixen type saddle supplied with the mount. This is the weak point when it comes to this mounts payload capicity. The all up weight of my telescope system is about 34 pounds. The thought of mounting my telescope on the CG5 saddle was just plain scary. If you look at the picture of the CG5 saddle in my review, you'll see 2 teeth about 2 1/2 inches apart on one side and a screw lock on the other side. These 3 contact points are all you have to carry the weight! Every time you use the screw lock to mount the scope your going to make gouge marks in your dove tail bar. Over a period of time this will really tear it up. The 6 inch ADM replacement saddle solves this problem. With the new saddle the mount lives up to it's advertised 35 pound payload capicity with no problem. The 2nd problem I ran into was with the power cord supplied with the mount. The cord comes with a nice screw lock feature to hold the cord tightly in place when pluged in. But you can't use it! The socket on the drive base is to shallow. You can't push the power cord plug far enough into the socket to engage the screw lock. With out the locking feature the power cord plug is to loose and the drive base looses power intermitently. This blows the mounts alignment every time it happens, which forces you to redo the alignment. A major annoyance. I bought a new power cord which I had to jury rig to fit tightly in the socket to solve the problem. The last problem I found was with the lubrication of the mounts drive gears. From other reviews I read some buyers complained that there wasn't enough grease on the gears or that it was to stiff in cold weather. I decided to take the covers off my drive base to check. To my shock I found no lubrication! The gears were running metal to metal! I used a light wheel bearing grease I bought at Auto Zone to solve the problem. Now that I have solved these problems the mount has performed very well. After balancing the scope it carries the scopes weight with ease. When using the 2 star alignment method plus 2 additional stars the go to pointing accuracy has been excellent. I hope this gives you a better idea of this mount. If you have any more questions let me know.

Warren

#16 AllanF

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Posted 18 December 2011 - 04:28 AM

Warren,

A question on the mount - I have the CT152 and the "outside" dimension of the carry handle included appears to be about 9.5" which you replaced with the mini dove tail bar. Just wondering which dove tail bar you ordered from ADM?

Thank you very much for generously sharing - making it almost too easy. The tip regarding the power cord is another that will save alot of frustration.

#17 WarrenM

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Posted 18 December 2011 - 04:55 PM

Al:
Glad I can be of some help. Regarding your question about the mini dove tail bar, if you have checked the ADM web site you have already discovered they don't make a bar 9.5" long. What I did was buy a mini dove tail bar for a 8" Celestron SCT. This bar is 13.5" long. To make it work I cut about 4" off using a 32T (32 teeth per in) hack saw. I used a fine flat file to make it even and smooth. I then drilled a 1/4" hole for the mounting screw. I used a 1/2" drill bit to counter sink the mounting hole so I could use a flat head mounting screw that would be flush with the top of the mini dove tail bar. On the other end of the bar simply use the 1" slotted hole that is provided. This turned out very nice and looks professional. There is another way to solve this problem that doesn't require any cutting or drilling. This method would require you to buy a Meade LXD mini dove tail bar that is 11" long and a VDUP11 Vixen dove tail bar that is also 11" long. You could use the VDUP11 to replace the Vixen bar that came with your scope and the LXD mini dove tail to replace the carry handle. These bars should bolt right up. This will increase the distance between your scopes cradle rings from 9.5" to 11" but that shouldn't be a problem. The down side is it will cost an extra $59. If you have any other questions don't hesitate to ask.

Warren

#18 AllanF

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Posted 01 January 2012 - 10:49 AM

Warren,
I have the CT 152 set up and balanced on a CG5-GT mount thanks to your tips. Anthony from ATM cut the dovetail bar to 9.5" which made it even easier. Just wondering it taking the cover off the drive base was a difficult project? Even indoors the gears seem to grind a bit even without the larger finder scope mounted. One last question from this relative beginner - what 2" eyepieces would you think are minimum to enjoy this particular scope? I have a decent Garrett SWA 32mm so far.

#19 WarrenM

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Posted 01 January 2012 - 06:29 PM

Al:
Nice to here from you again. It sounds like your telescope and mount set up is very close to what I have. Your going to love using it when you get warmer weather. Regarding your question on the drive base covers, the declination drive cover is easy to take apart and reinstall. This is the cover that is directly under the scope when it is mounted. To check the gears for lubrication I would take this cover off first. If you find the gears are well lubricated you can probably assume the right ascension drive is ok as well. But, if you find no lubrication, like I did, you'll be forced to remove the clam shell covers on the R.A. drive to check. This is the cover with all the sockets for the power cord, hand control, etc. This is a difficult job because of all the wiring and components they cramed in there. If you decide you need to take the R.A. covers off, try to note the position of everything in there as you SLOWLY pull the covers appart. I wasn't carefull with this and it took me over an hour to figure out how it all went back together. Everything has to go back the same way it came out or you won't be able to reclose the covers! As to your question on eyepieces, I've found that I use my Meade 2" 14mm U.W. by far the most on this scope. It gives 64 power with a 1.3 deg field which is great for many globular & open clusters, nebula and galaxies. For really wide field views I use my 2" Meade 40mm S.W. which gives 23 power with a big 3 deg field. Your 32mm should work well in this catagory. For higher powers I use my Meade 8.8mm U.W. and my Explore Scientfic 4.7 U.W. which gives 102 and 191 power. I also have a short 2" Antares 1.6 power barlow which I bought from scopestuff.com. I have found that these 4 eyepieces plus the barlow pretty much covers all my viewing needs, they give me a range of powers from 23 to 306. As always, if I can be of any more help with questions let me know.

Warren

#20 seeindoubles

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Posted 19 January 2012 - 11:15 PM

I read Larry Carlino's review and having seen the AT152, knew I had to get one. My experiences have been mirrored by Warren's review. This is one huge bargain. Mine has the 2" Crayford instead of the 3". Rotation not quite as rough. Views of Jupiter were best I have had, even through my C11.

#21 MKV

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Posted 21 January 2012 - 11:45 AM

Warren, if your 10-inch Meade SC doesn't split 1.1 arsec doubles, sell it! The fact that your 10-inch Meade seems to have trouble with it doesn't mean 5-inch refractors are better than 10-inch reflectors, as newbies may come to believe by reading your article, even if that was not your intent. That is true only if the larger telescope is poorly made, or poorly maintained.

My experience with A. Jaegers' 5-inch and 6-inch f/5 objectives (no longer available) is very similar to yours (except they used to cost far, far less). The c.a. observed never appeared as bad as the theory presents it. But that is true of other aberrations as well. The 5-inch f/5 Jaegers lens photographically resolved M13, and visually with averted vision.

Your article is an affirmation that short-focus achromats can look good, are easy to transport and set up and give decent very views visually and photographically.

Mladen

#22 WarrenM

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Posted 21 January 2012 - 11:51 PM

MKV:
I certainly hope my review didn't leave the impression that a 6" refractor is better than a 10" SCT or 10" reflector. That was not my intent. Each type of scope has it's own unique advantages. Even though my Meade 10" SCT is 25 years old, it is in better condition now than when I bought it new. I added computer controls and Bob's Knobs (for easy collumation). From Peterson Engineering I installed an upgraded focuser, to limit mirror shift, and a larger 2" visual back. This scope has performed well and still looks new. My two failed attempts to split Porrima with this scope were with it set up on a large paved parking lot (at Eastman Lake) about an hour after sunset after a hot day. There was still some heat radiating from the pavement that was affecting seeing on both of these ocassions. The theoritical resolution of a 10" SCT is around a 1/2 arc second but thats under ideal conditions, which doesn't happen very often. The night I split Porrima with my 6" CT152 refractor I was set up on grass in my front yard. A much better situation. If I had my 10" set up that night in my front yard I'm pretty sure it would have split Porrima also. Though not as easly as the 6" refractor did it. One thing I've learned since buying the CT152 is that no 10" SCT is going to produce the tiny pin point star images that a good 6" acromatic refractor can. When it comes to faint DSO's any good 10" will beat a 6" refractor because of its greater light gathering power. I hope this clears up any misunderstanding my review may have caused. Thanks for your interest.

Warren

#23 davidpitre

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Posted 22 January 2012 - 11:20 AM

My experience with A. Jaegers' 5-inch and 6-inch f/5 objectives (no longer available) is very similar to yours (except they used to cost far, far less)


In 1960s Jaegers' catalogue a 6" f/10 in a cell ran $175. .
If we take the date as 1965, it is roughly $1250. today. That is for the objective and cell only. So we are paying somewhere around half the price for these 6" f/5 Chinese objectives as a Jeagers 6" f/10 cost around 45 years ago.
I don't know if Jaegers made a 6" f/5 at the time, but a 5" f/5 objective in cell cost $97.50 in the 1960s. That is around $700. today.

#24 JS999R

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Posted 23 January 2012 - 09:51 PM

After reading Ed Tings, Warrens and Larry's reviews, I'm trying to somehow bring a CT152 home without my wife knowing. This is going to take some time to figure out and I may have to sell my Vixen 102 to do it. Believe it or not I don't think she will notice the difference in size between the two. I've done this a couple times in the past with motorcycles, I'm sure I can pull it off with a telescope.

What is the best way to attach the finder scope mount? Are there screw holes available on the focuser like the GSO focusers? The total deal will be over a grand counting the finder and diagonal. No doubt I'll have to pick up a good wide field 2" for it.

#25 Robo-bob

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Posted 23 January 2012 - 10:42 PM

After reading Ed Tings, Warrens and Larry's reviews, I'm trying to somehow bring a CT152 home without my wife knowing. This is going to take some time to figure out and I may have to sell my Vixen 102 to do it. Believe it or not I don't think she will notice the difference in size between the two. I've done this a couple times in the past with motorcycles, I'm sure I can pull it off with a telescope.


You sir, are my new hero. All hail the god of marital harmoney. Seriously though, I am going to give this a try.

Back on topic, has anyone had a chance to compare this scope with one of the older Antares 6" Achros? Just wondering how the CA would compare. Anyone?






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