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Takahashi FRC-300: 1-Year Anniversary

Posted by Melvin Schick   06/04/2007 12:00AM

Takahashi FRC-300: 1-Year Anniversary
Takahashi FRC-300: 1-Year Anniversary

It is pretty easy to be enthusiastic about new equipment, particularly equipment with a relatively long delivery lead time. I have noticed that many equipment reviews are written relatively soon after the equipment’s delivery point, which is also true of course for my own review of the Takahashi FRC-300, written one year ago. How are these original observations holding-up? What surprises were uncovered? And, what changes need to be made to my original opinions?

In the Disadvantages Section of my original review, I expressed concern over the potential difficulty in cleaning the primary mirror of the Takahashi FRC-300 should it be needed. I guess my fears at that time exceeded my understanding of the mechanics of the FRC-300 OTA. I had had a prior miss-step cleaning the lens of my Takahashi TOA-130, so this time I went out of my way to make sure that I learned how to correctly do the disassembly, cleaning, reassembly, and testing on the first try. I worked closely with Fred Garcia, who by the way is a genius, at TNR to get it right. Actually, it was not that bad. The whole process took only a couple of hours, and the results were perfectly clean and collimated optics. While cleaning is probably not a good idea and may not be needed in the high, dry climates of the western US, here in Florida with humidity in the 80’s and frequent dew points only 1 or 2 degrees below ambient, mirror cleaning is needed from time to time. My ability to relatively easily clean the primary mirror was a positive surprise. But without Fred’s help I probably would have loosened the bolts locking the primary mirror (which are readily accessible). This would have been a disastrous mistake and would have required a trip to Japan for the OTA.

Essentially all of the wonders of the Takahashi FRC-300 remain. I find myself just as excited about this magnificent telescope as I was one year ago. Here are some specifics:

1. As I do not have a fixed observatory site, I must move, setup, and align every night. I have a working process the gets this all done in about 15 minutes. The results are almost as good as having a fixed pier. I use TheSky6 and T-Point. The details are at ->
http://SchickWorld.com/Astronomy/Text/ParamountMEQuick.htm

2. Focusing remains easy and quick. I have not moved the Helical Focuser in the last year since my initial focusing which I described in the original article below. All digital focusing is accomplished with the FLI’s Precision Digital Focuser and FocusMax.

3. I had some initial uncertainty regarding my tandem telescope configuration atop the Paramount ME. Here too my earlier concerns were unfounded. There has been no noticeable flexure in this setup.

4. Balancing remains quick and easy and re-balancing is only required with major equipment changes.

5. I am able to capture both wide-field and deep sky objects with the same OTA.

6. Light gathering through the large aperture is great.

7. There is essentially no noticeable vignetting.

8. During the last few months, I have moved my attention and concerns from the OTA to the back-end of the imaging train... the CCD. I have replaced all of my SBIG equipment with CFW’s and CCD’s from Finger Lakes Instrumentation, LLC. I am enormously satisfied with my relationship with FLI and FLI equipment. Clearly these components make a big contribution to the quality of the final product. Someday soon I would like to produce a review comparing my experiences with FLI and SBIG and their respective equipment. Here is my new imaging system which employs the new Kodak 09000 full frame sensor in the FLI ProLine09000:



FLI ProLine09000>FLI-CFW-5-7>FLI-PDF>Precision Parts Custom (29.9mm)>FRC-300

One negative surprise was uncovered in the area of automatic temperature compensation. The FRC-300 has built-in automatic temperature compensation to around 5C. While I have not precisely tracked the temperature changes each night, it seems that a periodic, digital re-focus with FocusMax helps to improve the image quality. I had originally expected that only one focusing procedure per evening session would be required. I have found that here in Florida at least this is not the case, and 2 or 3 re-focuses are important each night.

The Final Results

The final proof of the quality of the OTA must be demonstrated in the quality of the images themselves. However, I still find it unfair to compare images from one astronomer to the other. There are just too many variables involved including for example alignment, tracking and guidance; total exposure times; filter and CCD differences; and how much Photoshop labor and skill are applied to an image. I can only report the noticeable improvements in my own images relative to one year ago. In my original review I used M51 and M16 as quick examples of images that demonstrated the FRC-300’s capabilities with both high magnification for galaxies and wide-field nebula imaging. I hope that by the 5-year anniversary the images will still be getting better. The FRC-300 is not constraining image quality in any way. The constraints arise mainly from my lack of skills. Here are the same Messier objects all from the same Takahashi FRC-300 at the 1 year anniversary, and of course it is fair to compare them with those in the original review:




The list price of the FRC-300, while never cheap, has significantly increased over the last year. As I mentioned in the original review, the hyperbolic mirrors were manufactured at least twice for my telescope. Takahashi quality is obvious. The street price reflects these very high standards. There are two ways to look at the price increase, and from my point of view my investment in Takahashi equipment has significantly appreciated.

Mel Schick
June 2, 2007

Original Review of the Takahashi FRC-300, published June 20, 2006:

The new FRC-300 arrived on a clear day in June, 2006. The telescope carried a serial number of 06001. I guess that I am the first new owner of this magnificent flat field Ritchey-Chrétien this year. I had been using a Mead 14” LX200GPS, and while it was acceptable, it was not up to the same optical quality that I was getting from a Takahashi TOA-130. So I took a big risk and ordered the FRC-300. The most painful part of the entire process was the waiting time. The time between the initial order and deposit and the order delivery was seven months. The wait time might have been a couple of months shorter except that the original mirrors apparently failed a Takahashi quality inspection/test. I am actually really happy that they found the problems as part of their high quality standards and manufacturing processes. This is much better than letting me find the problems after delivery. As Art from TNR said, “Quality takes time.” I very much prefer Takahashi over other telescope manufactures because of their truly outstanding quality; it is just that I am short on patience.

Before I placed the order, I assumed that the 2348mm focal length at f/7.83 would make the FRC-300 an outstanding astrograph while still giving enough magnification to take good galaxy images. With its 300mm of aperture I expected good light gathering characteristics, even though I calculated that there would be over 25% area obstruction of the primary mirror from the spider apparatus. With all other OTA’s that I use I had experienced heavy duty vignetting with the CCD camera. Would the FRC-300 do better? The specs promised a large Ø90mm image circle. While I am primarily an astro-imager, I also wanted to be able to come to focus though an eye-piece.

Delivery and Setup

The long wait was finally over. Since this was not my first telescope, I knew that I wanted to proceed slowly and enjoy every moment of the new setup. The OTA itself arrived in a very large package with impressive Japanese language characters handwritten on the outside of the box. (I hoped that it did not say… this is broken). I promised myself that on Day-One I would only take the first step of removing the OTA from its shipping container. This took about 10 minutes, and now I had to wait again for Day-Two.

The FRC-300 was well packaged and protected for its long shipment from Japan. I was able to remove the OTA from the shipping container unassisted even though it weighed in at a hefty 66 lbs. Art and the guys at Texas Nautical Repair had done their thing. They had carefully inspected the shipment and inserted some optional accessories that I had ordered, including a collimating telescope for the OTA.

Day-2: At this point I had decided not to set artificial limits on how fast and how far I would go with the setup process. This didn’t work very well for me either. While I had wanted to take my time with the setup, I completed everything else that needed to be done on Day-2. It was all too easy.

The primary goals for Day-2 were to mount the FRC-300 atop of the Paramount ME and achieve a balanced scope ready for use. I would place the FRC-300 onto a Casady M300 adapter plate which I had pre-ordered from Robin Casady. I also had ordered a Casady Tandem18 Bar. The Tandem18 slides easily into the Versa-Plate of the ME. The FRC-300 ships with two tube rings which match the holes of the M300 plate. I also mounted a TeleVue NP101 at the other end of the tandem bar to use as a guide scope for imaging. Both the FRC-300 and the NP101 are attached to the Tandem18 with Casady saddles. I was a bit nervous about the balancing, but it too proceeded very easily given all the movement possibilities from the saddles and the Versa-Plate.

At this point some might advise me that there will be too much flexure in this tandem configuration. I had pre-tested this approach using the heavier Meade 14” and the NP101 without any problems. So I am proceeding this way with the Takahashi FRC-300. Each time that I have used guidance with this configuration, the FRC-300 and mount have worked very well together averaging less than 0.4 pixels of combined corrected guidance error in X+Y.
Inside of 90 minutes everything was done and ready for some pictures itself:




Daylight Alignments

I needed to slow down as this was all happening faster than plan. So I took a break. I had lunch, and I did some emails… and waited. I decided that I would use the collimating telescope and verified that factory delivered collimation was essentially perfect. It was, and this test took about 15 minutes to do.

The time was now about 2pm on Day-2, so I decided that I should not wait (it might rain or something) and I would roll-out of the garage. I do not have an observatory or a fixed platform. My environment is nightly moves from the garage to the end of the driveway. Here I setup and re-align every night.



Since it was still daylight, I had the opportunity to do a terrestrial alignment of the finder scope with the OTA. This would also be my first experience with the helical focuser on the FRC-300. I was not expecting this to be easy, and it was not. The Back-Focus distance of the FRC-300 with just the native corrector is only 105.70mm. As I had feared, I could not get a clear focus on a stop sign that was about 200 yards away even after having fully rotated the “captain’s wheel focuser” all the way. Fred at TNR had warned me that this scope was really an astrograph, and I would not be able to use 2” oculars with it. However, I had purchased at Fred’s suggestion a Hutech diagonal. With just this little added focusing capability, I was able to see enough to get a 1st alignment adjustment for the finder scope. Good enough. I will leave the rest for closer alignment on the heavens using the camera. I really would not want to use the FRC-300 for much visual observation. The FRC-300 would work, but there are other better options at hand.

First Light

I took another break and some more pictures of the telescope, but I was giving-up with this go slow approach (maybe it would rain?). The time was mid-afternoon, and as I looked to the sky, I noticed a beautiful half moon east of the meridian. I decided to take first light with the FRC-300 at about 3pm using the moon as a target. Having some prior negative experience with the proximity of prime focus between visual and CCD imaging, I decide to do everything with the camera even though it was still daylight. I had read other reviews about the experience of others with large Ritchey-Chrétien telescopes and without fail there were complaints and expressions of difficulty finding the initial focus position. I have an SBIG STL camera and I use a Finger Lakes Precision Digital Focuser (PDF). The PDF lets me achieve a very highly accurate focus position. The back end configuration is as follows without using a focal reducer:

STL11000M>FLI-AD12>FLI-PDF>Precision Parts Custom (36.52mm)>FRC-300

As luck would have it, I was able to shorten the exposure time sufficiently to capture daytime images of the moon. Focusing with the big captain’s wheels was actually very easy. In fact it took only 10-15 minutes to get a crisp, good-enough-for-me first image of the moon. The time wasn’t even 4pm.




Imaging at Night

Finally sun-set arrived on Day-2. I took new flats and for luck a few new dark images. After darkness arrived, I did a quick Paramount alignment followed by a full T-Point model run. After I made the final fine focusing adjustments using the PDF, I was ready for the real test… to see FRC-300 images. This is the perfect telescope for me. I love its high quality optics and its sharp focus. As the temperature changes the FRC-300 has automatic temperature compensation so that a precision focus is maintained. This works within a 5 degree temperature range, and to this point I have not needed to use the similar capabilities within the PDF. I am just a recreational astronomer, and I have only enjoyed this hobby for 18 months. The images that I have taken with the FRC-300 are beyond my expectations. I have only had the system in use a few times, as the weather is Florida has become seasonally rainy. In these brief periods of observation, however, almost all vignetting has disappeared, images are in crisp focus, contrast is high and resolutions is very good. Since the first setting of the helical focuser, I have not had to touch it. All subsequent fine focusing is handled with just the PDF.

Below are a couple of new images from a beginner. You can also see more detail on my website at http://www.SchickWorld.com where I also discuss the various equipment comparisons in more detail. I hesitate to show my images as a positive testimonial for this magnificent telescope. I really am just a relative beginner, and I know that my images often are not as good nor as polished as those produced by others. I do not spend much effort making PhotoShop enhancements to my images, and I do not want to take-away from the truly outstanding capabilities of the FRC-300. I can only compare my new images with my own prior images made with the same mount and camera. The differences are striking and confirm my decision to buy from Takahashi.

Yes, it performs even better than I had expected. I get good galaxy magnification and with the same telescope I am able to see wide-fields for nebulas and clusters. I am a very happy camper.




Concerns

I wanted the FRC-300, because I do want to take great CCD images. The FRC-300 would not be my first choice however if I were doing primarily visual observations.

Here in Florida, we understand what it means to have moisture in the air. I have already observed some spots on the primary mirror. I use a dew heater, and I am as careful as possible, but this machine does not look like it will be routine or easy to clean.

Conclusion

The 7 month wait for production and delivery was painful. Maybe I am impatient or something. However, the FRC-300 was absolutely worth the wait. I only look forward to many years of fun in the dark with this beautiful, high quality telescope.

Mel Schick
June 20, 2006

Click here for more about this subject. -Ed.