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About celestron8g8

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    Proto Star

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    Wildlife and Astroimaging , Fishing , Hunting , Camping , Watching Community Theatre Plays .
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  1. I wish i could see that in RGB !
  2. Here some info and what to use : https://starizona.com/hyperstar/ Also there are videos on YouTube for other explainations :
  3. I would like to see you argue with manufactures of Focal Reducers and convince them otherwise cause all brands of FRs’ claim exactly what i copied/pasted above then gave a link to the quote . So just to let you know i wont argue with you but i usually go by manufactures description of their product . I know what your trying to say relating to resolution but resolution will be determined by the camera you use and the size of it’s sensor . I understand the more pixels the bigger the resolution where you cannot increase the image size without degrading it as where you can reduce an image without degrading it . What I don’t understand is why your so concerned with that theory over a FR ?? Especially if your not using one . What you should have done is reduce the larger image to the same size as the smaller image then do your comparison .
  4. Your are right for sure , especially if you have a big pocket book !
  5. So basically your just going by a theory and not actual facts . Sorry my bad for not understanding so i'll just bow out of the conversation . But I would like to mention a Focal Reducer is actually for this purpose and nothing else : "QUOTE" Focal reducers are primarily used in astrophotography to compress the light cone exiting the telescope down to a size closer to that of the sensor within your camera. This also results in a brighter image which reduces the exposure time. Focal reducers also reduce field curvature, providing the flat field necessary for astrophotography. "QUOTE" https://www.skiesunlimited.com/astro-imaging-accessories/focal-reducers/
  6. To get a better comparison you need to take an image with the same scope . When you change scopes your only changing the FL in the scope with the Focal Reducer attached . When I compare your images tho the f3 is slightly brighter than the f7 but since the f3 is smaller it's hard to compare detail properly . The only reason for a FR is to increase the speed of the exposure time and make the image brighter . Trade off is a smaller image due to a wider FOV but FRs' also can produce coma at the edge of FOV of the image .
  7. When you buy extra EPs' take into consideration the FOV degs . The 32mm Plossi I have is an older model and only gives me approx. 49 degs of AFOV . Celestron sells some that are now 60 and someat a higher cost but has 82 degs AFOV . If you can swing it buy as expensive as you can comfortably afford . Doesn't have to be Celestrons , Telvue sell some very nice EPs' but expensive . SO if your just getting into astronomy viewing buy wisely until you have got use to your equipment and how it works best for you . Remember it can get expensive if your not careful .
  8. If your not doing AP there really is no reason to have it . Main purpose of a Focal Reducer is to make imaging faster by changing your scope from F/10 to F/6.3 . this shortens the exposure time in AP . In return tho the trade off is it reduces the object size also . I have tried viewing with mine way back but I prefer not to use it for anything except AP which I haven't done in several years now cause I've retired from any AP . If your just wanting to view I would suggest a 32mm Plossi or maybe a 40mm Plossi for wide field viewing . I have a 25mm also that came with my C8 I bought back in 97' and it actually is my best EP for viewing planets and the moon which I used often with a 2x barlow . If you want to go higher viewing and not use a barlow then you might consider a 10mm or around 7.5mm without a barlow . just remember tho if you go higher power than what your scope recommends the viewing can start degrading and give bad viewing . Besides also when using very high power your actually looking past most objects in the sky , that's why I recommend lower power like the 32mm which you can use with your barlow which in turn makes it a 16mm EP so just remember when using a barlow it doubles your EP from whatever size it is .
  9. Sorry but i disagree . Even with cameras and lens when you add a teleconverter be it 1.4x or 2x it doubles your f/stop which limits incoming light . Scopes with EPs and barlows are really nothing more than a big lens and principles works same for both . Disagree if you wish but I’m through discussing this topic cause it seems it’s going nowhere on agreements . Have a nice day .
  10. When you add a barlow yes light incoming is reduced . Also since you are doubling your EP power for example if using a 20mm EP with a 2x barlow as you know you are viewing the same as if you were using a 10mm EP without a 2x barlow . That only makes since . Any time you add more glass to your line of viewing it will reduce incoming light . When referring to FOV it all depends on the FOV of the EP , but when you add a 2x barlow you are doubling all calculations . Maybe this link can explain to you what i'm saying . Read all the way down to the "Exit Pupil" topic and he shows the calculations . SInce I don't ever really worry about these calculations I don't remember everything all the time but these explainations usually are in most Owners Manuals , or least I know they are in my OM for my Celestron 8" SCT I've had since I bought my scope . Some times I wonder why the original question from the OP is even that much of a concern unless a person is a teacher at a school for astronomy or science explaining how optics work or is just curious and asking questions ? But reguardless here's the link : https://www.chuckhawks.com/telescope_formulas.htm
  11. IMPO , a true APO wins over your two scopes . However if funds are there the bigger the better if you could afford it . True APOs’ can take high power much better than any achro can and probably the mak too without degrade . However with true APOs’ to get the best view you need good EPs’ Televues for example . However the best you can afford is your choices . Example in the USA , Stellarvue make their own EPs’ to help match up their scopes . They can give great views . Also a factor is if you image an APO can give you excellent images and colors . Good luck on your choice of scopes tho !
  12. This review explains : https://www.chuckhawks.com/celestron_ultima_barlow.htm
  13. This is true with older SCTs' about mirror flop but if the OTA is a recent build in the last yr or so I believe Celestron has improved MF with their new SCTs' . Can't remember exactly where but I was just reading few days ago how Celestron improved the focuser to virtually eliminate MF . Now how correct this info was I can't prove it since I can't find my history where I read this . It maybe somewhere on Celestrons main website . But if his scope is new this should be something the OP doesn't really have to worry about now .
  14. IMPO you should stick with the second image . Your first image you over clipped the BP according to the histogram . I messed with it in PS and only could see a slight difference or improvement depending on taste using curves but only to the slightest amount that really doesn't make since to change . The only improvement could be in the trap section and you can do that but taking shorter exposures to expose the center stars better then doing a copy/paste by selection then feathering 1 or 2 pixels then copy and paste into this second image . other than that is multiple short exposures stacked with your other exposures then editing to your likeness .
  15. I agree with using a guide scope if possible . Celestron sells a Guide Scope package for $99.00 USD that is perfect for the 9.25 . https://www.celestron.com/products/80-mm-guidescope-package The OAG for that will run you $259.00 USD which is 2-1/2 times price of guider scope . https://www.celestron.com/products/off-axis-guider Watch this video on YouTube , this guy uses a the celestron guide scope with his 9.25 . It's just informational for how he uses the guide scope with a mono camera . (This is not me myself , just a YT video )
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