johnturley

Happy 1 April John

The latest BBC Weather Forecast is now indicating cloudy skies in Mexico on 8 April, and rain showers in Texas, ironically the best chance of clear skies now appears to be in the Great Lakes area, but all that could change. John

We were originally planning to observe the eclipse from near the Niagara Falls, followed by going to New York, and then a trans USA Amtrak Rail Trip ending up in and flying back from Sam Francisco. We decided to accept a lower chance of being able to observe the eclipse, offset by visiting New York, followed by the trans USA Rail Trip and San Francisco, however Astro Trails decided to cancel this trip due to lack of interest, so we opted for the Mexico trip instead. John

The best chance of clear skies (but not guaranteed) along the track of totality, is from the Torreon area in Northern Mexico, which is one of the observation sites that Astro Trails (UK Tour Operator) are organising, and with whom we are travelling. John

This would indicate that the Esprit 150 is significantly superior to the ED 150, I would be interested to hear from someone who has compared them. When I compared the view of Jupiter (and not under particularly good viewing conditions) through my Tak 100 DZ, with that through my Esprit 150, the 100 DZ (with a Strehl ratio measured by Rother Valley Optics of 0.987) did not even come close, the Esprit 150 was streets ahead. Note also that the 100 DZ is also technically superior to the 100 DC (which seems to be the benchmark 100mm Tak), although several observers have stated that there is no discernable difference between them. John

You could ask whether Rother Valley Optics could carry out a Zygo test on a C9.25 purchased from them, or whether they would allow you to reject the scope if it did not come up to the expected standard. I had a Zygo test carried out on my Tak 100 DZ, and the Strehl Ratio came out at 0.987, they informed me that if it didn't come up to the expected standard, then the scope is sent back to Takahashi John

Some observers used to claim that the C9.25 was superior to the C11 on planets, due to the longer (f2.5) focal ratio of the primary mirror, would be interested to hear from someone who has compared the two scopes. John

My Esprit 150 gives sharper planetary views than my 14in Newtonian on the majority of nights, although the the colour of the GRS, and the blackness of satellite shadow transits show up better through the 14in. John

I had quite a good view of Comet Pons-Brooks last night through my 14in Newtonian before it disappeared behind a neighbour's roof, and for the first time I was able to try out my Baader Swan Band Comet Filter, and it did appear to enhance the view. I would estimate that the magnitude is now around +6, in line with predictions, so it will have to brighten up quite a bit to be visible with the naked eye during the Total Eclipse of the Sun on 8 April. John

That sounds like a good plan, if just for visual with a C9.25, you could get away with an AZ-EQ5 or HEQ5 mount, but for imaging I agree that you would probably need an AZ-EQ6 or EQ6-R or equivalent. John

My C9.25 gave quite good planetary views, and I personally wouldn't describe them as mushy, unfortunately I never got round to comparing the views side by side with my Esprit 150 when I owned both scopes, but my feeling is that the Esprit 150 gave sharper views. One point bearing in mind however is that my Esprit 150 resides in an observatory shed (piggybacked on top of my 14in Newtonian), whereas my C9.25 (CPC version) was stored in a conservatory (which can get quite hot in summer), and would have suffered from longer cool down times. Based on several observers comments, it does seem that the optical quality of C9.25's can be quite variable, some suggest that the Edge HD versions are more consistent, but a lot more expensive. I bought my C9.25 from Rother Valley Optics, who are quite local to me so that I was able to pick up the scope in person, and they did check the collimation for for me before I picked it up, and if you purchased from them, you could ask whether they could carry out a Zygo test like they do on Refractors. As mentioned in another thread, I would recommend purchasing the OTA and mount separately, rather than getting the CPC version, you would would them be able to mount another scope such as a 4in APO on the same mount. John

If the SW 150 ED performs anything like the Esprit 150, you will see a lot more detail compared to the 100 DC. John

If the OP is looking for a general purpose scope, I would be inclined to go for one of these while on offer, plus save over £1,000 compared with the price of a Tak FC 100. John

A couple of months ago, I compared the views of Jupiter and the Moon through my Tak 100DZ, with that through my then ES 127 FCD 100, and Esprit 150 Refractors. The view through the Tak did not even come close to that through the Esprit 150, which was streets ahead of that through both the 100DZ and ES 127. I would expect the Esprit 150 to have the edge over the Skywatcher 150 ED, but they may well be close, and I think someone on Cloudy Nights did a comparison between a Skywatcher ED 150, and a TEC 140, and the ED 150 compared quite favourably. One point to bear in mind though, is that according to Es Reid, the quality control tends to be better with the larger Esprits (he vary rarely has to adjust or send one back), which also I think have a more robust lens cell than the Skywatcher ED Refractors. Regarding the comparison between the ED 127 and the Tak 100DZ, I thought that they were very close, but maybe the 100 DZ had the edge over the ES 127, when it came the sharpness of the view. Bear in mind though, I purchased the 100 DZ, mainly because I wanted something lighter and more portable than the ES 127, rather than because I expected it to give superior views. Some Tak owners also state that they can comfortably use 100x or even 125x per inch of aperture with their Tak scopes, this may well be the case when it comes to double stars, but on Jupiter, and admittedly not under the best of viewing conditions, I felt that the 100 DZ ran out of steam if I tried to go above 200x (50x per inch of aperture), and found the image rather dim and nor very sharp. John

Based on the comments observers have made in other threads, there does seem to be a lot of variability in the optical quality of C9.25's, if you get a good one it will be an excellent planetary scope, and at the time I got mine they were highly recommended by Damien Peach (a renowned planetary imager), and some claimed that they gave better results on planets than the C11, due to the longer focal ratio of the primary mirror. I don't know whether the quality control is better with the Edge HD versions, but they are a lot more expensive, although the 8in Edge HD works out about the same price as the 9.25 XLT. My C9.25 was quite good on planets, but other observers have said that theirs' gave mushy views, and were outperformed by a 4in APO. Unfortunately I never got round to doing a side by side shoot out with my 14in Newtonian and Esprit 150 (which is an excellent planetary scope, but big and heavy), before I sold my C9.25. As I stated in another thread, I would not recommend the CPC version of the C9.25, as (especially with suffering from back problems), I found the combined OTA and fork mount too heavy to lug around) John