Poll for new telescope.

Hi all!
I want to buy a longer focal length telescope for imaging smaller targets like galaxies..
currently i have:
Esprit 100ED 550mm
QHY 268mm + filterwheell + off axis guider (ASI 120mm)
SW EQ6R-PRO

so im thinking :
Askar 120APO 840mm
Celestron 8HD 2000mm + focal reducer? (o dont think the 11" is a good pair for my mount…)
TS ontc 8" about 800mm.. (collimation is a bit hard for my laziness..but i can manage..)
or anything that maybe be better option…
Thanks for the answers!

Sean Mc:
9.25 edge?

yes better from 8" HD? im worried about my mount..

Not long enough. I image at 3000mm

MaksPower:
Not long enough. I image at 3000mm

Nice! but i will need new mount....

I'm in a similar situation. I'm also looking for a good and reliable scope around 1000mm. I'm considering the 140apo, and the 130 phq. Actually I'm using a FRA400 and love it. Virtually trouble-free and extremely sharp. I came from a SW 200/800 and in the past I wandered about the 8-10 ONTC too, but after some email found that the delivery period is extremely long (4-6 months). Actually I'm looking at the SCA260 too. It's pretty fast and the fl fits my needs. I'm only concerned about collimation. The scope will be installed in my remote site so the mechanics needs to be reliable. Another aspect is the cost….at the same price you can buy a 151phq that as far as I know is a great scope. I have no experience with the edge line. A lot of people with my mount use the C 9.25 -C 11 with excellent results. But in my opinion the sct design is not optimized for remote usage.

Impossible to answer w/o knowing the conditions it is to be used in and the targets you wish to image as well as the mount it will be on.

Agree with Bill that your seeing conditions and mount will matter a lot in tbis decision.

The EdgeHD scopes are slooow at f/10 and I do not recommend the reducer having personally used it on an EdgeHD 11.

If you want to keep your EQ6R-Pro, an 8” imaging newtonian is probably what I would recommend unless you have really good seeing and can go with the 8” EdgeHD without the reducer.

Ani

hi

for me celestron 9.25 EdgeHD

some day if you want , you could down the focal with reducer 0.7x.65x.0.8x
in this case for galaxies bigger is better

CS,Brian

If someone tells you not to get the EdgeHD because its slow, disregard them, and just take more data. 11HD works just fine on an EQ6R. But if you want to do a reducer, get the 9.25, it has more consistently good optics across the production vs the 11 and 8, and allows you to use a Full-Frame format. I hate using my 8" reducer.

I would recommend other than those listed, a 10" Ritchey Chretien.

For a lot of galaxies the tighter the field of view, the better. For reflectors I prefer SCTs because I don't like diffraction spikes. Then with Starizona's corrector is far better than Celestron's. The only thing I don't like is the collimation. I pretty much only take out my C8 during galaxy season because I don't like fiddling around with having to collimate it. It's really not hard, but in the summer I don't want to waste the little imaging time I have with it.

I would consider Askar's 130PHQ too instead of the 120APO if you do go with a refractor.

If you’re going to go with a longer focal length, you might end up needing a better guide cam as well. Maybe even a new OAG if the one you have doesn’t have a mirror large enough for a new guide cam. I found that the 120mm mini was virtually unusable with my 8 edge.

I noticed on the equipment list here in Astrobin that the Celestron Edge HD 8" has the highest rank on posted images. Its a proven piece of hardware.

My personal experience is with the TS-Optics RC8 F8 (steel version), I think manufactured by GSO, and I advise the carbon version with the flattener.

I wish the perfect telescope would exist, but obviously it doesnt. The same question is also currently on my mind. At the moment I am still a beginner with an Askar V.
The EdgeHD would be my favorite, if I would have a backyard where I can image the whole night. But since I need to carry everything out to places in the neighbourhood, dont have a car and being cursed with bad weather, I am thinking about an 6" f/4 Newton to get most out of my precious few clear nights. . An 8" Newton would also be nice, but is already getting somehow hard to carry. WIth a barlow lens, both would also have enough focal length. A huge refractor would be cool as well, but probably too heavy and to large for me to carry.
What is more important for you: Focal length or a fast telescope?

You might want to look at a 8" F5 newt at 1000mm. Thats still faster than many of the other options, but you might prefer the longer focal length of the SCT's or RC's. Collimation at F/5 should be issue-free. You could even get the televue paracorr which increases the focal lenth a bit further. I would recommend an OAG (and preferably a 220 or 274 guide cam) for long exposures with newtons though, and look for a newton with a good focuser. Also, I can really recommend spidervanes made in one piece, either milled or 3D-printed. Those really aid in collimation stability. You could be buying cheaper with the newton+upgrades in comparison to other options also.

8" SCT works fine with EQ6R Pros and is good enough for a lot of galaxies, so I vote that

newtons are a little harder for the mount to handle, but it would also work

I have a friend with a 9,25 SCT on the EQ6R-Pro. It works. The off axis guider is good but I recommend a new 174 camera (oem for less money) for the guide camera…

Good luck! CS Tim

I have a C8 edge HD, and in my humble opinion it is a great scope. I like to run mine without a reducer.
I did use it with an EQ6, got good results with that. I use a long FL guide scope, which is very old fashioned (C80) but it works great (for guiding).

Since you are also considering the C9.25, I think that may be also be a good choice. I would also recommend a tribahtinov mask - I'm still testing mine but it seems to be great for a quick collimation in the field.

Kind regards,

Ian

If someone tells you not to get the EdgeHD because its slow, disregard them, and just take more data. 11HD works just fine on an EQ6R. But if you want to do a reducer, get the 9.25, it has more consistently good optics across the production vs the 11 and 8, and allows you to use a Full-Frame format.

This seems like good advice to me. With my C8 edge I have no problem getting decent subs in SII, OIII or Ha narrowband with 300 seconds.

Ian

Ani Shastry:
Agree with Bill that your seeing conditions and mount will matter a lot in tbis decision.

The EdgeHD scopes are slooow at f/10 and I do not recommend the reducer having personally used it on an EdgeHD 11.

If you want to keep your EQ6R-Pro, an 8” imaging newtonian is probably what I would recommend unless you have really good seeing and can go with the 8” EdgeHD without the reducer.

Ani

Hi, Why do you not recommend the EdgeHD reducers?

I am in the exact same situation as you. I think the 8" SCT is probably the best option on this list if you want a lot of FL and something that isn't too much for your mount.

Personally, I am undecided between the Celestron 8" EdgeHD and the Apertura 8" RC (below). Not sure if you looked at the latter, but could be another option for a slightly different price and specs.

https://www.highpointscientific.com/apertura-8inch-rc-ritchey-chretien-carbon-fiber-telescope-8rc

I have a C11EdgeHD and a RC10. I use them both. Get the 8" SCT…

CS Tim

Tim Ray:
I have a C11EdgeHD and a RC10. I use them both. Get the 8" SCT...

CS Tim

May I ask why the SCT over the RC? I'm curious.

I vote for the C9.25. With an 550mm APO in your possesion already, a step up to 800mm won't be much a difference imo. With longer focal length you get a whole new view of the sky with the possibility to shoot much smaller targets. You will appreciate the galaxy season more

Don't be afraid of f/10, you can always bin to gain additional SNR. If your sky quality is not excellent, then you won't even lose detail.

Derek Vasselin:
Tim Ray:
I have a C11EdgeHD and a RC10. I use them both. Get the 8" SCT...

CS Tim

May I ask why the SCT over the RC? I'm curious.

My big OTA's (The C11EdgeHD and RC10) constantly underperform in my location. I live directly under the Jet Stream air current, this air current is devastating to the quality of the seeing in my location. Probably the largest usable aperture is 8". With that said, the SCT is easier to collimate, maintain collimation, the mirror locks mitigate mirror flop, and the versatility of Hyperstar gives you two scopes in one. The RC is open tube and cools to ambient temp quicker, ,mine has a FT focuser and is rock solid on the backside. I have 4 ota's shoehorned into a 12' x 12' roll off roof observatory. If I ever downsized number of scopes, the RC10 would be the first to go. I like my RC, I like my SCT. I just like the SCT more!

CS Tim

longer focal length telescope?

Related discussions