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Essential extras for a C9.25 SCT?


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I'm waiting to hear from FLO about my new C9.25 coming in and was wondering what extras would be good to go with the scope? I am mainly interested in planets with a view to imaging them in the near future. I have a HEQ6 mount, so that part is taken care of. I also have a SPC900 which I want to try out.

My thoughts are:

Heated dew shield and controller

Desiccant Cap

9 and 18mm Celestron X-cell LX eyepieces

Any other suggestions?

I wondered about a barlow. Are they useful on a SCT?

Thanks!

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A x2 Powermate would be good (for imaging planets). An f/6.3 reducer if you want to image wider field with camera.  A 2" diagonal is required for larger eyepieces, maybe a fine focuser of some sort (motorised preferably). Maybe some filters - UHC,OIII and coloured (for visual). Loadsa eyepieces :)

ChrisH

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The celestron eps work great I have the full set and the same scope ,mines on a pier on a c gem head I would go for a,10/1 focuser if I was you a dew shield and dew control is,a must the cap if ya want but I never bothered and of the 8 people I no ,none of them have this

Pat

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Yep - an heated dew shield is a must - you could choose different focal length EP's if you plan on getting a Barlow - if you barlow the 18mm - this will give you a 9mm EP with a lot better eye relief, not sure if the 925's come with a 40mm -so if you get a 25mm ish and a decent Barlow, this will give you 40mm  and barlowed (20mm), with the 25mm Barlowed (about 12.5mm) - so 4 magnifications and you only have to buy 1 other EP and a barlow.  The 12.5mm would be near to the maxing out on the mag on say, Jupiter, but you can choose your EP's to suit and always add to the collection later, the Moon and Mars may hold higher mags, but with Mars quite low down, the more mag you try, the softer the image becomes.

I have always found the focuser on the 1100 very nice to use, with very little image shift when altering focus - not had any experience with other better quality focusers - but I tend not to use a very high mag, just back off a little, I find a smaller image with more defined detail works for me, but you will settle on your own choices, everyone's different.

Also found the binoviewers a real treat - not sure if its my eyesight, but from using one EP to using two, gives me a lot more depth of colour, I've only tried them on Jupiter up to yet, but have found it to be a very relaxing experience.

Also a good power tank (17ah) to run the scope in the field - make sure you get a good connection to the power "hole" on the scope, if you use a slightly smaller diameter power pin, you may loose power half way through and have to keep re - aligning - also remember to cover the power light with the end cap (the one you look through) of the finder - its VERY bright and will drive you mad !!!

Try to store the scope as near to outside temp as possible - this will keep the dew from forming - but its inevitable with a closed tube scope - don't worry about it - everyone with an SCT has suffered to a certain extent.

Don't need to tell you this, but the cheapest upgrade you can get is just to "use it" the more time you spend at the EP just looking -  wether it be Solar System or farther a field - just look - pure and simple the more you look the more you "see".

Paul.

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Paul - love your philosophy, its so true. The best investment must be time - time spent using it.

I'm a bit confused on the merits of a micro focuser as opposed to a Crayford style focuser, or vice versa . Any thoughts?

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I use the Astrozap heater, controller and also the separate dewshield (although you could opt for the combo version).

 I have also recently bought the Celestron Luminos 2.25 (2") barlow which I am finding pretty good, although you would need a 2" diagonal. Certainly having a large apeture ota you would be advised to get a 2" diagonal in order to do it justice. Also I have a Hyperion Aspheric 36mm ep which coupled with my 2" gear and the large apeture of the C9.25 does give you some nice wide views of the sky.

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A Feathertouch Focuser, and a Baader Visual Back with a built in Click-Lock, also  a Telrad, on the dew prevention i have a Astrozap with built in heater, plus another that goes around the outside, my Diagonal is the baader with a Click-Lock, changing EP's or installing a Camera is just a click away no fumbling about in the dark with cold fingers its no cheap but dropping a expensive EP isn't either......

DSLR Attached....

DSC_0013.jpg

DSLR plus FR attached....

DSC_0012.jpg

Take the DSLR out and insert the Diagonal and EP

DSC_0011.jpg

Remove the FR so just the EP, The EP's are just a click and change...

DSC_0009.jpg

All done in the pitch black with cold fingers safely, no screwing the dark... :)

Edited by Tinker1947
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Definitely a Heated dew shield; wish I had bought one. I was out the other night after it had rained; lots of moisture in the air;  just after 22.00hrs Mars appeared in the southern sky just above my roof top.............unfortunately, by that time everything was covered in dew so I was only able to see a very poor image...............But, the eyepieces I think were suffering most!! Anyway, think its time to get a heated dew tape at the very least!!

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That happened to me the first time I went out with my C9.25, Martin. I had a dewshield, but no heater. Within an hour or so the scope was unusable as the front had fogged up. Once I had got a heatertape and controller the problem was solved.

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That happened to me the first time I went out with my C9.25, Martin. I had a dewshield, but no heater. Within an hour or so the scope was unusable as the front had fogged up. Once I had got a heatertape and controller the problem was solved.

Thanks Malc; you've sold the idea of me getting one :rolleyes:

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I'm a bit confused on the merits of a micro focuser as opposed to a Crayford style focuser, or vice versa . Any thoughts?

Maks and SCTs focus by moving the primary mirror up and down the outside of the central baffle tube.  The mirror rides on a carriage that is pushed/pulled by the focuser.  Because there must be some space between the carriage and the baffle tube to allow freedom of movement between the two and because the focuser usually just pushes or pulls on one edge of the carriage there's a slight rocking motion of the mirror when the focuser changes direction.  For visual use it's probably barely noticeable.  For planetary imaging at five metre plus focal lengths it can be a bit of a pain because the image moves across the camera sensor.  With an SPC900 that might be sufficient to move it all the way from one side of the sensor to the other or even more.

The microfocuser is well-regarded and improves the general performance of the standard focuser, but my understanding is that it cannot address the problem of the mirror shifting.

With an external focuser the idea is to get the focus generally correct with the standard focuser, then use the external focuser for the final adjustment thus avoiding moving the mirror again.

I'd suggest that perhaps if your goal is visual or wide(-ish) field imaging then a microfocuser probably does the job nicely.  If planetary imaging is your thing then I think the secondary external focuser probably makes more sense.

At the cheaper end of the secondary focuser market there is the Revelation SCT Crayford (and an almost identical Skywatcher one) and a Revelation rack and pinion model which also seems pretty good.  Both can be motorised with a little DIY effort and the standard Skywatcher motor focuser kit (or a completely DIY mechanism).  The parts arrived to do mine this morning, so I may well be doing one this afternoon :)

James

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Some good tips here.

The most useful things that I have added are:

Dew shield - essential

Motofocus - not essential but it's a real boon to be able to do very fine adjustments without touching the scope. I only do visual (so far!)

Telrad - I think essential as I could not get on with the supplied finder

Clicklok for the diagonal- I found it to be a real pain to fix the diagonal in the right position without it

Clicklok for the eyepieces - bit of luxury but very nice!

Kerry

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Kerry's point about the finder is a good one.  I'm not sure they fit the same finder to all models, but mine came with a largely useless 30mm finder.  I bought a 9x50 Skywatcher finder and shoe to replace it.  The shoe fitted using the existing mounting holes but I had to buy some different size screws (the originals were too short and the ones that came with the finder foot were metric rather than UNC).

I think someone on SGL (Michael Wilkinson, perhaps?) has fitted a 70mm scope to his SCT as a finder.

James

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Dew shield and heater is a must. I use a Kendrick band.

Skywatcher finder upgrade but your dealer should have offered you this.

Interested in the other tips above. The mirror shift is a pain for imaging so I will look into fixing this.

Very interested in the 2" upgrades described. I wouldn't have thought it made any difference at these focal lengths so I need to be re educated on that one!

Sent from my iPhone using Tapatalk

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The Revelation Crayford focuser seems to get very good reviews on SGL and others, but seems to be unavailable?

It's identical to the Skywatcher model bar the logo as far as I'm aware.

James

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