What new scope for Lincoln AS?

[Red meteor]

Lincoln AS have been using a 12 inch Newtonian by Fullerscopes since the observatory was opened by Patrick Moore in 1982 and we are considering a replacement. At present it is just the OTA we are looking at, but ideally the mount would be replaced as well (limited funds). The mirrors in the old instrument have been recoated three times in recent years but have not lasted well. The scope is in a skeleton tube and has suffered from dust collection and condensation (sometimes running off the mirror), so we think that a closed tube should help with both those issues.

The telescope is mostly used for casual observing by members and for public open evenings and group visits. There has also been some imaging by a small group of members and would probably be used more if it were updated. It was originally the telescope of the late Walter Pennell and some may remember his photos on the cover of The Astronomer. It was donated by his son and has served those purposes well for many years.

We would appreciate if others on this forum could share with us their experience and recommend suitable instruments. We have been looking at another 12 inch Newtonian, the Skywatcher 300 being around £630 but is it worth paying £1,200 for a UK produced model?

There are some images on our website www.lincolnastronomy.org

Regards,

Graham Winstanley, LAS Secretary

[mikeDnight]

Last question answered first, NO! Buy the SkyWatcher and save yourselves a fortune. 

Another alternative would be to buy an SCT, which would double easily as both a visual and imaging instrument. Or, you could buy several instruments such as a good sized Newt, a Maksutov Cassegrain, and may be a ED Refractor.

Mike 

 

[Mr Spock]

Are you sure it's Fullerscopes? The pic on the site looks like an AE Optics OTA on a 'B' or 'C' type mount.

Anyway, for observing convenience an SCT would be a good choice. Celestron go 9.25", 11" and 14" depending what you can afford. Any of those would be better than your current (aged) 12" Newt.

[ollypenrice]

An SCT ticks many boxes. It is closed, compact, has decent optics and sufficient aperture. It would be excellent for lunar and planetary imaging and observing.

There are boxes it fails to tick, as well, though. With the 10 inch class the focal length is long, so field of view on attractive widefields is restrictive. The bigger they go, after that, the more extreme the FL becomes. This is something to bear in mind. The other issue would be deep sky imaging where the SCT is a bit of a handful because the focal length is inappropriate for DSLRs and the guiding precision needed is extreme. DS imaging performance, other than with the costlier ACF or Edge versions, is indifferent. Large SCTs command low prices on the used market and are good value.

I would suggest using a small and inexpensive refractor for DS imaging riding on a larger visual instrument. If you went for a Newtonian I would buy a budget one like a Skywatcher. If you bought it from FLO you'd be assured excellent customer service. This might not be the case from all British Newtonian manufacturers...

Olly

[Peter Drew]

Based on our experience at the Astronomy Centre I would say that the largest used SCT you can afford would suit your purposes, specially if you pair it with a used small APO refractor. We have all manner of types of telescopes and apertures but the main telescopes in constant use are the big SCT's. 

[John]

11 minutes ago, Peter Drew said:

Based on our experience at the Astronomy Centre I would say that the largest used SCT you can afford would suit your purposes, specially if you pair it with a used small APO refractor. We have all manner of types of telescopes and apertures but the main telescopes in constant use are the big SCT's. 

This is the conclusion that my astro society have come to as well. We currently have a vintage 12" newtonian and an 18" JMI dobsonian but our ambition is to replace them with a large aperture SCT.

 

[Red meteor]

Thank you for the replies.

I am sure you are correct about our scope being from AE, it is certainly 1960's vintage.

We already own an old 10" SCT donated to us a couple of years ago and this was on use at a public open evening on Saturday. The observatory was originally designed to house an 18" Newtonian, but after completion of the building enthusiasm for grinding the mirror waned. We have the glass blank gathering dust - would anyone like to take it on? We feel that the Meade would look rather lost in the dome so we are keen to go for the wow factor of a large reflector. Having a small APO attached would be great.

As pointed out by Olly the longer focal length of the SCT is a slight disadvantage. We find that the 12 inch f5 is an ideal all-rounder for planetary and deep sky. Buying a new SCT is a lot more expensive.

Unless anyone has negative comments about the Skywatcher 300PDS that is the route we are thinking of taking.

Thanks again for your input.

Regards,

Graham

[John]

One of the advantages that we found with the SCT design (for outreach use) was that lower cost eyepieces deliver good results and you don't need short focal length eyepieces (with their tighter eye relief) to get reasonably high magnifications.

For children (we get a lot of those at the observatory) we find the eyepiece height of the newtonians awkward. We decided that we did not want inexperienced people standing on steps to reach the eyepiece and the fork mounted SCT eyepiece is at a convenient position.

Nothing wrong with the Skywatcher 300P's though - lots of scope for the £'s

[Mark at Beaufort]

Graham it was great to read your website with its history.

Herefordshire AS has an outreach event every month and although we have a Celestron 8" SCT the most popular scopes are a 12" and a 8" Newt.

I am not an expert on astro imaging but I would have thought that a 12" Skywatcher would cover both your needs especially if you have a quality mount.

[Peter Drew]

1 hour ago, John said:

One of the advantages that we found with the SCT design (for outreach use) was that lower cost eyepieces deliver good results and you don't need short focal length eyepieces (with their tighter eye relief) to get reasonably high magnifications.

For children (we get a lot of those at the observatory) we find the eyepiece height of the newtonians awkward. We decided that we did not want inexperienced people standing on steps to reach the eyepiece and the fork mounted SCT eyepiece is at a convenient position.

Nothing wrong with the Skywatcher 300P's though - lots of scope for the £'s

I agree with John. The 300mm PDS is unquestionably good value and would cover most bases but I share the ergonomic concerns. We went for the "wow" factor with a 30" but found in practice that it was difficult to operate and many were reluctant to mount a tall construction necessary to reach the eyepiece, this pretty much excluded children, the ones we most wanted to engage with astronomy. We replaced it with a 16" SCT and have never looked back. The 30" is now mounted outside and comes out of its housing on tracked wheels. I can't remember when we last used it!  

[Red meteor]

4 hours ago, Peter Drew said:

I agree with John. The 300mm PDS is unquestionably good value and would cover most bases but I share the ergonomic concerns. We went for the "wow" factor with a 30" but found in practice that it was difficult to operate and many were reluctant to mount a tall construction necessary to reach the eyepiece, this pretty much excluded children, the ones we most wanted to engage with astronomy. We replaced it with a 16" SCT and have never looked back. The 30" is now mounted outside and comes out of its housing on tracked wheels. I can't remember when we last used it!  

Thanks John and Peter. I appreciate your concerns but we already have experience with a 12 inch Newtonian. Several years ago we did away with the wobbly aluminuim ladder and built some sturdy wooden steps with hand rails all the way round. To move the steps we just pick up the end and then they move on wheels like a barrow. We have lots of visits from children and apart from a small area of sky there is no problem with access to the eyepiece. With a closed tube we will be able to rotate it to make the eyepiece easier to reach.

[Peter Drew]

The most important thing, no matter what the telescope, is that it is made available to as many people as possible. Good luck with the project.

[ollypenrice]

I made a wheeled platform with handrail for use with our 20 inch Dob, though it isn't too tall being F4. The platform is cumbersome though. (It has two wheels and two legs, so it stays put when parked.)

Olly