Posts Made By: Ivan Ong

Thanks Klaus and John for your helpful hints. To me, it boiled down to 3 things. The first was the wide mount T ring not sitting well and hence the off axis problems. The second was improper cool down. The third which I hope was not the case was pinched optics giving rise to astigmatism.

So tonight I made sure the OTA was cooled down 2 hours. I made sure the wide mount T-ring was absolutely secure. I am happy to say that the resultant frames are pin-point edge to edge. Besides the huge dust bunny on the frame, I see the illumination is not even. I think this is more of a problem of the Hutech IDAS LPS filter I was using.

Klaus- did you get the 1:10 fine focuser? I do not have one-I'm thinking of getting it. Focus is definitely very sensitive on this puppy. I had to focus 3-4 stars to get it right.

This is M37 by the way.

Ivan

I tried out some astrophotography with the Takahashi Epsilon 180ED two nights ago on the Blue Ridge Parkway. The resultant photo is a composite of 10 frames at ISO 1600 with a Canon 20Da. Scope was at f/2.8. In general, the greater signal to noise allowed the delicate features to show better. I have taken a more gentle processing approach here. One thing for sure- I really need flats. I will have to work on some this weekend.

Ivan

Hi, I needed a star diganoal with my STV if that helps.

Best,
Ivan

Amy,
Did you buy the Sphinx new? If new, that is quite unusual.
The following are based on my previous ownership:
-Like most mounts, the Sphinx should make very little noise when tracking. Can you describe the noise? Clattering? Electronic whining? Pulsing?
-Slewing should be smooth, there is noise of course, but it should not be loud or clattery.
-The DEC axis has the rotating clamp arrangment. If that is loosened, it should be lightly stiff to move with your hand. The RA axis is looser and should move relatively freely. If you have seen a Takahashi EM-200 mount, the Sphinx axes has more resistance than that. The EM-200 axes are very free moving when unclamped. The Sphinx axes have a slight resistance to them. However they should move freely when compelled by your hand. Certainly not very stiff at all. What is your load weight on the mount when you are trying to balance?
-There is a backlash compensation feature on the hand held star book that will let you compensate backlash settings (unless you have a very early software version, then you can update on the website). If your slew rate is set too high, you might see some jumping. Other then that, the actual gears are not easily accessible and are hard to adjust. The DEC backlash on the Sphinx tends to be bad and makes guided astrophotography very hard- but for visual use it is ok.
-one thing: the GOTO on the Sphinx should be very accurate. Make sure yours is.

Good luck
Ivan

Here is the same photo with some ID.
Ivan

There's always next year

That's the kind of tripod they use for off-shore drilling. Nice setup.
Ivan

I used the Eagle pier. I had the pier raised on the highest setting and then added the extension pier (I was using my refractor earlier and was too lazy to change back)- so I was a little worried about all that height- turns out it was quite ok.

Ivan

Hi Rex, none of the Canon DSLRs offer this feature. The hand helds e.g. SD800 have the preview option. The 20Da has two levels of magnified preview for focus, but not a general full screen preview.

Ivan

Sharp and nice! I like it. I've seen it about 2-3 times. It is nice to have charts and predict when it would happen and very exciting to see it occur right on cue!
Ivan