0.00
#...
·
 |
|---|
|
Hello, sorry for this question. I couldn't find a complete answer anywhere. I want to buy myself a telescope for both observation and astrophotography. I am currently using my school's telescope (Meade lx85 8" Newtonian) for both observation and AP. The telescope I want is Celestron advanced VX 6" Newtonian. (I think the tube is the same tube as the C6-N.) Competitor telescopes are generally not available in my country. Anyway. my question is if i buy this celestron avx 6" newtonian telescope, can i focus with DSLR without moving the mirror? My second question is do the screws on the back of this tube hold a cap? Or is collimation done with those 3 screws? Or is collimation not possible? My 3rd question is does this tube accept 2 inch eyepieces? Thanks |
7.90
#...
·
|
|---|
|
1. It depends on the DSLR but in general I'd think that you could focus but most likely it won't work with any coma corrector. 2. Collimation can only be done with the 3 screws on the secondary holder. The back isn't available for collimation unless you remove the rear cap 3. No. |
|
0.00
#...
·
|
|---|
andrea tasselli: Thanks again for the reply!! So when I remove the 3 screws on the back, I will gain access to the collimation screws, right? |
|
7.90
#...
·
|
|---|
Thanks again for the reply!! So when I remove the 3 screws on the back, I will gain access to the collimation screws, right? Presumably, but I have never seen the back without the cover on. |
|
0.00
#...
·
|
|---|
andrea tasselli:Thanks again for the reply!! So when I remove the 3 screws on the back, I will gain access to the collimation screws, right? I understand. I hope as you said, there is no focusing problem with DSLR. |
4.02
#...
·
|
|---|
|
Buyer I have a C8-N and I might resell it; not because it's bad but because I found out I'm not the type of person to take care of Newtonians and adjust the mirrors and all that. Maybe it's because of my experience; I supposedly collimated the thing with an Orion laser collimator, stuck a plossl in there, pointed to Jupiter and expected to see something amazing or at least inspiring. What I saw was horrifying  .Jupiter was a very bright oval dot like an illuminated egg and had a brownish line running across it, off-center. The stars were all thin short lines on a grayish background. (the gray background was probably due to my location, but it added to the miserable scene) And I expected to take amazing planetary and DSO photos? Duh... Maybe it's my fault, and it probably is, but I I've been noticing a lot of old people (experienced people) end up with a simple refractor. Why? because they cannot handle all this stuff anymore, especially since Newts are heavy. Maybe I'm just overwhelmed, but this is my opinion. Newtonians are for patient, perseverant people with moderately large muscles (lol) and a moderately large backyard that they own. It also works very nicely with a observatory dome. FYI here are the cons: Too heavy for me and my mount Not easy to maintain Cheapish focusers. I would need to buy another one for astrophotography Primary mirrors with clips cause uneven star diffractions and I would need to buy an aperture mask or ring for astrophotography Too long Star aberrations and warped field will force me to buy an expensive coma corrector for astrophotography Pros: Fast F/5 focal ratio long 1000mm focal length cool star diffractions because of spider dew cannot reach mirrors in most cases That's basically it. What do you think? |
|
4.02
#...
·
|
|---|
|
In the realm where stars unfold their cosmic might, Where dreams collide with celestial light, There lies a task, dreaded and profound, The horrors of collimating, astound. A reflector, a portal to the depths unknown, An instrument of awe, a soul to own, But within its design, a sinister jest, A dance of mirrors, a cruel behest. With tools in hand, a seeker's heart, I step into a realm where chaos imparts, The alignment of optics, a delicate tango, A dance with frustration, where patience must hang. Beneath the velvet sky, I start my plight, To coax the universe into crystal-clear sight, The primary mirror, a tempestuous beast, Its perfect alignment, a maddening feast. As I adjust the screws, the tension grows, The heavens whisper secrets only it knows, Each tweak, a whisper, a delicate touch, A dance of precision, a universe to clutch. But within the struggle, doubt takes its toll, The mirror's defiance, a relentless stroll, Each adjustment brings a new aberration, A fleeting moment of astronomical frustration. |
|
0.00
#...
·
|
|---|
Buyer Thanks for your explanations. but if i buy an apo for the same price as a 6 inch newtonian, won't i face such downsides?: 1- Since it has a smaller aperture and focal length, it will collect less light while observing dso and planets. the objects will look small because the focal length is less. 2- For astrophotography, especially since galaxies are small, if I crop, won't the image get distorted? |
|
7.90
#...
·
|
|---|
Thanks for your explanations. but if i buy an apo for the same price as a 6 inch newtonian, won't i face such downsides?: You don't get to buy an APO for the price of a 6" low-end newtonian, I'm afraid. If you want to image with a DSLR then you'd either get a cheap but good lens to work with (but you need at least a tracking platform) or you get a half-decent newtonian with imaging in mind, such as the SW130. And, yes, you'd need a coma corrector and those aren't cheap either. |
|
4.02
#...
·
|
|---|
| @Eta_Carinae To answer your questions first: 1A. It will collect less light, but it's definitely not incapable for astrophotography. For visual it's a different story, you'll need dark skies for the average refractor to work more visually for DSOs. 1B. Objects will be smaller, but you should always start wide when starting astrophotography then gradually go narrower when you learn and have more experience. 2. If you crop the image, it will not get distorted. For a petzvel design apo, such as a Redcat 51, you don't need a coma corrector. You might not find many cheap APO refractors, but you should look on astronomics.com, their astro-tech ED refractors are cheap, and many beginners start out with those (you'll need a flattener also). Here is a good ED doublet for example https://www.astronomics.com/astro-tech-at72edii-refractor-ota-fpl-53-f-6.html?___SID=U And here is the flattener for that doublet https://www.astronomics.com/astro-tech-8x-reducer-field-flattener-for-the-60ed-and-72ed-optical-tubes.html There are no reviews for it which is strange. But you can believe me when I say astro-tech refractors are really good for the price. If you have a moderate amount of money, you should look at William Optics, they're very good telescopes but also require flatteners (besides the Cat series). Watch Youtube reviews too, it helps. Also look at this Astrobackyard page to see if you like any of the refractors it mentions there https://astrobackyard.com/beginner-astrophotography-telescope/#:~:text=The%20Sky%2DWatcher%20EvoStar%2080ED,between%20performance%20and%20price%20point. |
|
4.02
#...
·
|
|---|
| Or you can do what Andrea is saying and get a lens and tracker setup which is a good choice. |
|
4.02
#...
·
|
|---|
|
Or you can use a Redcat 51 with a star tracker. It will be roughly around $1300. But don't forget the necessary accessories. Like this https://www.youtube.com/watch?v=YVtl_nZLDoQ |
0.00
#...
·
·
1
like
|
|---|
| @Eta_Carinae I've been using my C6-N for DSO images recently. It came with the VX mount when I bought some years back. I also have a Redcat51, but needed some more reach for galaxies this season. Although not ideal, you can get some good images using it with a DSLR. Took this image of M51 with Canon T7i, AsiAir Plus, 30mm Guide Scope and ASI120mm for the guide cam. Processed in Pixinsight using Blur X Terminator, Noise X Terminator and some clean up in GIMP:  |
|
0.00
#...
·
|
|---|
@Eta_Carinae thank you very much for your suggestions i really don't have a budget to buy an apo and i have little or no access to these apo in my country i hope newtonian will do the job for both observation and ap. Since I already have some Newtonian experience, I don't have much difficulty, do I? |
|
0.00
#...
·
|
|---|
@Eta_Carinae Man, I really appreciate this photo. a truly amazing m51. This made me want to get this telescope. Wondering a few things? - How long is your total exposure time? - How much shutter speed did you use for one shot? -What is the bortle level of the place where we took the photo? And do you use filters? Sorry if there are too many questions  |
|
4.02
#...
·
|
|---|
| @Eta_Carinae If you believe you're the type of person who can handle Newtonians, go for it. But it's not for me. |
|
0.00
#...
·
|
|---|
| @Eta_Carinae : Thanks, all 60" exposures at ISO400. Taken over two nights, 172 images one night, then another 177 the next, for a total integration time of 5.8 hours. Shooting from suburban Los Angeles county, bortle 8/9. No filters used. I think when I bought the Advanced VX, it was $799, plus another $100 for C6-N, so not really a big investment. Just started doing DSO around October last year, starting with M42 with a Canon Zoom lens mounted on the AVX. Then picked up the Redcat, great scope! But when galaxy season presented itself, realized I had C6-N I hadn't used for AP that was DSLR ready with a 750mm/FL, so used what I had. Coma is pretty bad in the corners, and as others have mentioned, you can't use a corrector with the stock focuser. Still, happy with the results I'm getting being relatively new to the hobby... |
|
0.00
#...
·
|
|---|
@Eta_Carinae If you believe you're the type of person who can handle Newtonians, go for it. But it's not for me. Thank you for your support and suggestions. |
|
0.00
#...
·
|
|---|
@Eta_Carinae : Thank you for your answer really nice result from the white zone. I'm wondering how many second exposures I can get with the C6N and AVX. I guess coma won't be a big problem for me. Can you send an uncropped photo for me? I wonder what the coma looks like. |
|
0.00
#...
·
|
|---|
| @Eta_Carinae Hello Eta, just uploaded to the public area, file too large for posting here.. |
|
0.00
#...
·
|
|---|
@Eta_Carinae Thank you very much indeed you help me a lot. Yes it doesn't look very nice but i think i can handle it |
