Celestron Edge HD 8 - Orion 10" Astrograph - Skywatcher 250/1200 PDS Explorer - purchase advice

[chris_33]

Right now i am imaging with a Star Adventurer and a 300mm telelens on a dslr. 

I am planning to upgrade to the eq6-r pro and currently i am searching for a telescope. i want to take pictures of nebulae, galaxies and planets. 

My first idea was to get the Skywatcher 250/1200, then i read that it is too big for the eq6, i was recommended a shorter tube like the orion 10" at f/3.9 or a SCT, due to my budget i can't get higher than the edgeHD 8 unfortunately.

what would you recommend? i am also open for different suggestions, thank you :)

[RolandKol]

Hi hi,

I am with SW 130PDS at the moment and also think of upgrading into something more expensive and EdgeHD is the first on my list

I think if you have enough funds fro Mount + EdgeHD, - go for it... EdgeHD is almost universal as it is native F10 which is minimum for galaxies, also it will be better with planets with or without barlow.

and with 0.7 reducer you may fit some nebulas in FOV.

Just keep in mind,

EdgeHD at F10 will need a very good guiding and NEQ6 R will have to work at his limits... Out of axis guiding will be handy... Not sure yet.. As I have not got my HD yet

 

[tasheeya]

Looks like Skywatcher 250/1200 OTA is around 14.5kg, I'm using an Orion 10" F3.9 Newtonian Astrograph + EQ6-R pro without any issue. its an 18kg/40lb setup with accessories and i can get 15min subs or more if needed and out of the box 0.6-0.7 arc second total RMS. EQ6-R pro can handle 20kg AP gear according to manual and user experience. here is my report on the setup if it helps. http://www.astronomyforum.net/astronomy-reports-forum/259561-guiding-eq6-r-pro-40lb-18kg-ap-gear.html

note that this setup ( and any large OTA regardless of the weight) will be very sensitive to the wind. Also both mount and OTA are heavy, not easy to handle/transport.

manual says payload : 20kg (for astrophotography)

link to SGL EQ6-R pro owners club

setup is new so i haven't had the chance to get many images. this is the one i have completed so far. taken with D5300a DSLR

 

other reviews.

https://astrojolo.com/gears/sky-watcher-eq6-r-review/

https://www.darkframeoptics.com/blog/mount-performance-charts-1

[alacant]

1 hour ago, chris_33 said:

get the Skywatcher 250/1200

Hi. That would be my choice. I'm using an old -blue-tube- 250p on a 13 year old EQ6, set up for galaxy season last year. Works great. 

Just my €0.02. HTH.

[vlaiv]

RC scopes in 8 or 10" variants could be also something to check out.

[chris_33]

1 hour ago, alacant said:

Hi. That would be my choice. I'm using an old -blue-tube- 250p on a 13 year old EQ6, set up for galaxy season last year. Works great. 

Just my €0.02. HTH.

do you have some kind of observatory? because i keep reading that this setup is sensitive to wind and i don't really have possibility to comletly shield it from it

[chris_33]

11 minutes ago, vlaiv said:

RC scopes in 8 or 10" variants could be also something to check out.

thank you, i will do that as well, do you know any specific scopes i should not miss?

[chris_33]

1 hour ago, tasheeya said:

note that this setup ( and any large OTA regardless of the weight) will be very sensitive to the wind. Also both mount and OTA are heavy, not easy to handle/transport.

yeah, the wind thing is the only thing that concerns me about that combination.

short question, do you loose many subs due to star trails? because with my star adventurer i can only use like 40 to 60% of my subs, i just want to know what i can expect

really nice picture btw.

[tasheeya]

2 minutes ago, chris_33 said:

yeah, the wind thing is the only thing that concerns me about that combination.

short question, do you loose many subs due to star trails? because with my star adventurer i can only use like 40 to 60% of my subs, i just want to know what i can expect

really nice picture btw.

these mounts are in entrirly different class than star adventurer mounts. you will not loose any subs due to tracking errors if you are guiding and there is no much wind. i took the above with occasional wind so the subs are limited to 5min. i had to remove 2 subs out of 38 due to strong wind bloating the stars.

thanks.

[tasheeya]

10 minutes ago, chris_33 said:

yeah, the wind thing is the only thing that concerns me about that combination.

short question, do you loose many subs due to star trails? because with my star adventurer i can only use like 40 to 60% of my subs, i just want to know what i can expect

really nice picture btw.

if the wind is a big issue, you should consider a refractor than large Newtonian/RC or SCT tubes. they all will act like a sail in the wind.

[chris_33]

5 minutes ago, tasheeya said:

if the wind is a big issue, you should consider a refractor than large Newtonian/RC or SCT tubes. they all will act like a sail in the wind.

the thing is, i don't know how much wind is too much, and i can't really remember how much wind there was in the clear nights i was out, because it was never an issue 

i also don't know how much observatory tents do help or if i could build something myself, the transportation isn't really a problem after all

i just read through your report, looks really good, at least i know weight isn't an issue

[alacant]

49 minutes ago, chris_33 said:

do you have some kind of observatory?

Hi. No, but I do have a sw 130pds which I use if I feel that the wind is gonna be a factor. I've not found the wind too much of an issue though.

[vlaiv]

14 minutes ago, chris_33 said:

the thing is, i don't know how much wind is too much, and i can't really remember how much wind there was in the clear nights i was out, because it was never an issue 

i also don't know how much observatory tents do help or if i could build something myself, the transportation isn't really a problem after all

i just read through your report, looks really good, at least i know weight isn't an issue

Issue with wind is not easy one to describe as it depends on various factors, and each setup will be different. Even two "identical" setups will behave differently in the wind for all but top class equipment where there is good QC and sample to sample variation is very small. Things to consider with wind:

Size and shape of the ota. General guideline - larger the ota - more susceptible to wind. Not all scopes are the same. Compact scopes have advantage over longer ones due to arm momentum (for same diameter and weight). Sometimes larger, heavier short OTA will have advantage over slim but long one (depends on length).

Next is sturdiness of clamping - you want very stiff clamping and you want your OTA to minimally flex on pressure (this is in part related to ota construction / materials used).

You also want to minimize backlash in drive train of mount. Backlash means play in each axis - and wind can "use" that small play to move OTA back/forth in both RA and DEC. Less backlash you have - the less impact of the wind.

Mount drive also needs rigidity. Some belt driven mounts have certain elasticity (acts in similar way to backlash) - wind can induce vibrations.

And finally - stability of mount / tripod combination as well as vibration suppression capability.

To put things in perspective, I'll give example of my current setup. I've got 8" RC on HEQ5 mount. Mount has been modded (belt mod/tuning, replaced dovetail clamp/saddle plate, replaced tripod for strong wooden Berlebach planet) and this is wind related performance on average in good seeing (just eyeballing it and from memory):

- completely still air - ~0.4" total RMS

- 1-2m/s breeze (one would not normally say that wind is blowing, but you can see leaves moving and cigarette smoke is not going straight up but at an angle) - 0.5" RMS

- 3-4m/s - you can hear wind in trees and feel slight breeze yourself - ~0.5 - 0.6" RMS

- 4-5m/s - stronger breeze and gusts - 0.6 - 0.8" RMS

- over 5m/s I usually don't bother with my setup.

[chris_33]

1 hour ago, vlaiv said:

- completely still air - ~0.4" total RMS

- 1-2m/s breeze (one would not normally say that wind is blowing, but you can see leaves moving and cigarette smoke is not going straight up but at an angle) - 0.5" RMS

- 3-4m/s - you can hear wind in trees and feel slight breeze yourself - ~0.5 - 0.6" RMS

- 4-5m/s - stronger breeze and gusts - 0.6 - 0.8" RMS

- over 5m/s I usually don't bother with my setup.

finally someone giving me numbers, thank you very much

[vlaiv]

2 hours ago, chris_33 said:

finally someone giving me numbers, thank you very much

Just keep in mind that those are "eyeballed" figures for my setup in my back yard (one could say I'm a bit shielded with house, fence and some garden growth, but I still feel when it's windy). Also, speed of wind is from forecast not actual measurement, but I guess it's fairly accurate - on multiple occasions changes in wind speed were forecast and guide graph responded accordingly, but it's always mix of seeing and other factors, so as they say, your mileage may vary.

[chris_33]

58 minutes ago, vlaiv said:

Just keep in mind that those are "eyeballed" figures for my setup in my back yard (one could say I'm a bit shielded with house, fence and some garden growth, but I still feel when it's windy). Also, speed of wind is from forecast not actual measurement, but I guess it's fairly accurate - on multiple occasions changes in wind speed were forecast and guide graph responded accordingly, but it's always mix of seeing and other factors, so as they say, your mileage may vary.

of course i get that, the thing is every person is different and when i read someone complaining that he doesn't get pinpoint stars because of the wind i don't know if he expects his setup to work with 30 m/s or if it was at 0.3 m/s, your numbers give me a feeling of what to expect, and that was very helpful