Third refractor to almost matching two same refractors?

[TareqPhoto]

Hi all and happy new year,

For this year i will try to minimize my buying of gear but finalize or finish what is missing from last 2 years of purchased items, trying to have consistent gear for really long term and never looking back.

I have two TS-Optics 90mm CF triplets, i only used one the first one as i keep the second for later when i get a better mount or second mount anyway, and the one i am using/testing is showing really nice quality and i am happy, i didn't post examples around because i have some issues with my computers, but that didn't show the real quality of the scope really, so now i think i want to go far and add a third one to match those two in FOV mainly, if for quality too then a bonus, but i think it all depends on what i want to do, actually the third one can be used for certain data, so if i have say three telescopes and for example two OSC cameras and one mono then i can use one OSC for RGB and the mono for Lum and maybe Ha but i decided to use it for SII instead, so the third camera if i buy as OSC will be for dual band [Ha/OIII], now what do you recommend for that third telescope if it was you to decide?

 

1. 102mm f/7 achromatic or FPL-53 ED doublet (or FCD-1 triplet) + 0.6x reducer [stars will be removed] + IMX571C + dual band filter
2. Third 90mm, so it will be exactly same setup as two 90s i have, both are used with 0.8x reducers and ToupTek IMX571 [M & C], here i will go with IMX571C can be used for RGB stars only
3. 110mm f/6 such as StellaMira doublet + Starizona APEX 0.65x + IMX571M + SII 3nm
4. 70mm f/5 Petzval + 294C, for stars only
5. 80mm f/4.4 6-elements + 294C, also for stars only
6. RedCat 51 or equivalent + 183 color, stars only
7. My Askar FRA400 + IMX571C stars only, or IMX571M with dual band for Ha/OIII

 

I can make that 90mm + 0.8x = 432mm as main FOV, or go with something little wider, i don't want to go longer, even 435mm-440mm i don't want, so it is almost the above options are what i could find, and they are almost affordable, less then $1500 or less than $1000, the soon budget will allow me to get one but without a camera, i even can use any above as individual alone such as 102mm or 110mm if necessary, but most likely i will do my best to put many many telescopes all at once for use per night rather than using only 1 or 2 per night, it never was good ending using 1 setup for me anyway, and i was testing two scopes together and i had few/minor issues i will fix later hopefully, so with another mount later i will try to use like 3-5 scopes at once if possible, i prefer to use mostly refractors of 80-120mm range, longer than that then i have my Newt/RC, smaller than that i already have two 60mm done or even Canon lenses, so i want to be at average 100mm aperture scopes more or less, i don't mind if achro or not good quality ED doublet so i can remove stars and use the ones from the CA corrected ones, that is why i want three scopes [or more] so i don't waste nights collecting data for each filter or band, i doubt i can spend many nights collecting data of each filter for one target only mostly if it is narrowbanding target or galaxies.

Thank you

[tooth_dr]

If you get three scopes, then get three mono cameras - you can shoot SHO in one go Ha Oiii Sii, or shoot Lum, Red and Blue and make a synthetic green and have a full colour image in one go.

I run two scopes at the same time and it's enough of headache keeping track of data and the correct flats, darks, bias etc.  CMOS cameras with their short subframes mean I'm sometimes dealing with 1000s of frames - any more scopes would be a huge task and use a lot of storage space.  Running five scopes would be a nightmare TBH.  Not to mention the logistics of mounting and aligning that many scopes.  The alignment saddles alone would absorb your entire budget.

It's not how much data you collect, it's how you process it, and a lot of the really good experienced APs on here can make great images from mediocre amounts of data.

IMO get your computer issues sorted and start enjoying the one scope and go from there!

[TareqPhoto]

32 minutes ago, tooth_dr said:

If you get three scopes, then get three mono cameras - you can shoot SHO in one go Ha Oiii Sii, or shoot Lum, Red and Blue and make a synthetic green and have a full colour image in one go.

I run two scopes at the same time and it's enough of headache keeping track of data and the correct flats, darks, bias etc.  CMOS cameras with their short subframes mean I'm sometimes dealing with 1000s of frames - any more scopes would be a huge task and use a lot of storage space.  Running five scopes would be a nightmare TBH.  Not to mention the logistics of mounting and aligning that many scopes.  The alignment saddles alone would absorb your entire budget.

It's not how much data you collect, it's how you process it, and a lot of the really good experienced APs on here can make great images from mediocre amounts of data.

IMO get your computer issues sorted and start enjoying the one scope and go from there!

Start from the last line and going up.

A. I was using one scope for few years say 2-3 years, wasn't happy really, didn't make anything better, i did the journey with one so time to try with two or three or 10 together.

B. I tried with two scopes setup and it was ok, i saw someone before on a site where he was using three scopes, and another one using two, so if those people were able to use two or three why can't others, sure it will be headache, we got enough headache with one setup already so it doesn't matter with more now.

C. I mentioned that i will think about getting another scope, if it is a good scope then most likely i can have like 2 scopes on each mount, so total 4, going with more scopes only a matter of time and setup quality, but not necessary, i will try to stay within 2-4, i mean what is the purpose of having two nice mounts that can handle two or three scopes but ending up using only one setup, no sense. 

D. Aligning two scopes isn't easy, but not impossible, i have that alignment saddle i can use for scopes, i have three different models but one is so expensive really [ADM], but i can work on that slowly until i finish it.

E. I have one color now already, so the third camera will be a batter between a mono and OSC, for one OSC i have two options, either RGB so one mono left for Lum, but i don't want to use a filter wheel/drawer to change filters, and i was thinking about buying a dual band filters that can give Ha and OIII from one filter with OSC, and i have SII i can get with the mono, so two cameras can give me Ha/OIII/SII, then i have to decide if third camera should be just OSC or a mono with RGB filters, headache for autofocusing each if the scope isn't a true APO corrected quality, and it means i need to add an item which is the autofocuser, a lot to think about here.

 

I bought a mini PC which is better performance than my so old laptop i used for astro, that fixed a lot of issues, and for storage, i think this is least worry thing, i bought 5TB for planetary and 4TB HDD for DSO, that planetary drive is full already in 2 years while that 4TB is still at half or less from DSO files since 2018 including 100-200 bias every time and 50 flats, so it can be managed, i can easily buy more drives, they became cheaper nowadays.