Posts Made By: Jerry Wise

Hi folks. Just been reading the thread Giorgio has on the Pentax. Thought there might be some good input I could get on a new TMB 130SS.

I'm new in the APO world and certainly not a star test expert. I've done a fair amount of work with SCTs and comfortable with star testing them but this APO analysis looks as if it can get complicated. Reason I say this is in this thread:

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/1443948/page/0/view/collapsed/sb/5/o/all/fpart/1

some say an APO could have a star test like the one shown and have an excellent lens.

When the unit arrived I thought it looked fine but then I mounted a Tak FS-78 on top of it and looked at the Trapezium. I could see the F star in the Tak but could not make it out in the TMB 130SS. The test was duplicated over several nights. In a star test on an artificial star and generic star on inside focus the pattern looked pretty good. As you moved through focus to outside focus the focused star seemed to stay and grow as you moved to outside foucus. Ending in the large bright shimmering blur shown in the star test photo. I'm sorry my shots are not better. I was using a Televue X 5 barlow trying to get as close to focus as possible on the star test.

The dealer says the star test doesn't look right but some of the others feel it is fine. Any ideas?

I recently picked up the new Takahashi FS-152 doublet Herb had on sale here on Astromart. About the same time a friend of mine ordered an AP-140 and also a Tak TOA-150 to tide him over while waiting on the 140. He was pleasantly surprised when the AP-140 showed up (he was on the list early through Company 7). With two APO scopes he selected the AP-140 over the Tak and made me a deal I couldn't refuse on the TOA. I've been wanting to compare a doublet vs triplet for some time now but never expected 6" scopes would be the test. The FS and TOA are mounted side by side on a Robin Casady Triad bar atop an AP-1200.

The weather gave me part of the night Wednesday to do a quick first light check out before closing down. Though low in the sky I gave Vega a look. As expected, the TOA 150 showed no discernable color on Vega even moving in and out of focus. The FS-152 showed a greenish cast on one side of focus and a slight purple cast on the other. However, as it approached focus the color appears to go away completly. The results are the same using a Nagler 7mm type 6 or Nagler 3.5mm type 6. The question is, as focus is approached with usable magnification is it possible a doublet can be designed and manufactured that will become in essence color free at or very close to exact focus?

I've been lucky enough to do a running comparison on a Takahashi FS-152 vs TOA-150. Both on the same mount using a Robin Casady Triad plate. A number of images taken with both scopes show the TOA needs a field flattener on a DSLR size chip while the FS-152 looks fine. I ordered the TOA field flattener. Looking at the flattener it looks as if it has two lens elements. With three glass elements already in the scope and two additional elements in the flattener, is there not some light loss going through all that glass? At least more susceptability to adjustment and QC problems? Both have excellent images with the TOA a slight edge visually on Mars. The color is (of course) better. The contrast is great in both with maybe a slight edge to the doublet. I have to make a decision eventually on one for imaging and worry about the extra elements.

TOA 150 Double Cluster image with edge magnification:

I did some looking around for figures on the TOA 150 for a discussion on another site and came across a description of the TOA 150 in another dealer's ad copy. I have a TOA 150 and I'm right happy with it but I wasn't aware it was performing at this level.

"Orthoscopic means perfected visually and Apochromatic means you're free from those strange violet glows which often accompany bright stars or planets. Thanks to the ingenious design of layering an FPL-53 Extra-low Dispersion glass element between two extreme quality crown and flint elements - perfection ensues. And what's more, it's air spaced, so there's no oil between the elements to leak or become opaque with age. The lens cells are durably constructed to withstand transport - yet are fully able to be collimated should the owner wish to make adjustments. With 1/12th wave accuracy and an airy-disc Strehl ratio of 0.992, the optics on the Takahashi TOA-150F Ortho-APO are as near to perfection as you can get!"

Like many, I'm in a holding pattern until I get my EMail from AP on a 140, 160 or 1xx anything. My current scope is a TOA 150 and it does a fine job, both visual and DSLR photography. I'm moving from DSLR (or splitting my time anyway) to entry level CCD now that SBIG is coming out with the 8300. With the extremely rare nights of good seeing in this area I want to optimize every minute under the stars. I was looking at the TEC 160FL and TEC 160 wondering what the difference would be between the two and how they compare with the TOA 150. Discarding the 10mm difference would the TOA color correction approximate the 160 or 160FL? (The TOA 150 is $8,995, the TEC 160 is $8,800 and the TEC 160FL is $12,500.)

Pretty much what I found with mine. It was one of the first 50 with the original focuser. The focuser actually had image shift just like reversing focus in the average SCT. The views were good but not Tak sharp. Imaging was OK with it if you got over that focus shift. What sent mine back was comparing the 130ss to a Tak FS-78 on the Trapezium. E and F were solid in the 3 incher and winked with F often missing in the 130ss. Both were mounted side by side on an NJP looking through the same air column. As Mr. Yang said, a good value for the money and it gets you "in the game". The sample I had wasn't quite an AP or Tak though.

I took delivery of an AP-1200 last fall. As close to perfect a mount as you will find. Do a drift alignment, understand Orthogonal, and it will track forever with excellent gotos. Without a lot of setup every time you use it. I had a Takahashi NJP originally and decided to keep it for a backup and "lug and go" mount. After working with the AP-1200 I ordered the Mach 1 and sold the NJP. Both mounts are as good as it gets. I swear I think profit is secondary and perfection primary in Roland's business model.

Somebody just did some work on TMB-130ss returns. I was impressed with his comments on CN. Knowledgeable and certainly didn't pull punches. I'll do some searches. Anybody know who that was?