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Old 01-07-2018, 08:13 PM
TareqPhoto (Tareq)
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Wide field APO refractor ... which one?

Hi again,

I am planning to get another scope for imaging than my ST80, and i keep thinking about either expensive one which means i have to wait 1 year or so and keep saving or start with whatever affordable now and don't think about high end expensive ones yet.

In my plan there are 2 options if i want to go cheaper and only for wide field imaging, and they are:

1. APO triplet 80mm + Reducer [the scope must be at least f6, not f7 or 6.5 or f8]

2. APO quadruplet so it already has a flattener, but 70mm or 60mm ones so it is already wide [300-400mm range]

Which of those two options above you prefer to go with?

And if so, then which brand or manufacturer? i really want a nice quality one, many will mention many scopes and all are good, but sure one can be slightly better than all other or tested and reviews to be as highly recommended, so what do you suggest/recommend?

Thank you again!
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Old 01-07-2018, 10:55 PM
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kosborn (Kevin)
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Take my reply with a grain of salt because except for a very cheap and effectively unusable 4" Newt, the only telescope I've owned is my current SW Esprit 100ED. It's an apochromatic triplet which comes with a 2 element field flattener. It is a 550mm focal length, 100mm aperture f/5.5 and I couldn't recommend it more highly. I've read reviews where it is compared to a Tak FSQ 106 (https://www.cloudynights.com/topic/4...sw-esprit-100/) and it isn't too far behind (for much less cost).


Kevin
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Old 02-07-2018, 07:33 AM
kens (Ken)
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I'm interested in the responses. I've been looking at the Borg 55 http://www.iceinspace.com.au/forum/s...54&postcount=1 and the Vixen FL55 mentioned in the same thread. Alternatively the TS 71mm F/4.9 https://www.teleskop-express.de/shop...-flatener.html
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Old 02-07-2018, 08:03 AM
glend (Glen)
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An 80mm APO Triplet (f7 typically) with reducer corrector become f5,53 . Plenty fast enough for imaging, circa 440mm focal length. Most have good imaging R&P focusers. I have one of these.
Then there are the new wave of 60mm ED (FPL-53) scopes around f6 with flattened, from WO, TS, Astrotech, etc, circa 360mm focal length. I have one of these. Of course if you have the money there is the TAK 60.

Generally speaking, the 80mm is a better all-rounder imho. You will get good field coverage, for example the Rosette Nebula fits the field perfectly, as do many other nebulae.

The 55mms are too small into to be of much use.
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Old 02-07-2018, 02:22 PM
Wavytone
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There’s this 86mm f/5.4 quad APO with 3” focusser and a 60mm image circle...

https://www.teleskop-express.de/shop...field-APO.html
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  #6  
Old 10-07-2018, 01:46 AM
TareqPhoto (Tareq)
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Hey again,

Thanks for your posts.

Still i didn't make my mind about anything yet, on Facebook someone recommended me to go with something like 100mm scopes because i do have Canon lenses including the best one i have 300mm f2.8L IS mk1, he said with this i have to forget about any APO refractor in 60-80mm and directly go with 100mm, and i asked in many groups there about how can i attach or place any Canon lens on my mount, and they always go with wrong answers such as how to connect lens to camera but i have connector or how to use ring holder on the lens, but my question was simple as how can i use the Canon lens alongside with guide scope whatever on the mount, they are all connected to cameras, but then i can't place them on the mount together and the answers are like going in circle or no direct answer, one or 2 gave good answer but the links are for stores i never use or can't use, so it remains like either i can't find a way to use my Canon lenses with guide scope so i must buy an APO refractor or just keep waiting the right answer with links to stores i can order from and can ship to my country.

For 100mm i was hoping to keep saving and then buy Takahashi FSQ-106 and never look back, if i managed to use my Canon lenses then i can wait for 100mm scope and so i will save for a Tak, if i buy Esprit maybe one day i will buy a Tak then i can't sell this Esprit and it will be a waste.

I am not sure about TS scopes, sounds good reviews but i don't see so so many images and results out of them to justify one, 2 or 3 nice images aren't enough, when i look around i barely can see many images from those TS scopes, so i try to avoid them and go with popular names instead [SW, Orion, ES, Celestron, WO,....etc]
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Old 10-07-2018, 02:25 AM
JA
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Quote:
Originally Posted by TareqPhoto View Post
Hey again,

Thanks for your posts.

Still i didn't make my mind about anything yet, on Facebook someone recommended me to go with something like 100mm scopes because i do have Canon lenses including the best one i have 300mm f2.8L IS mk1, he said with this i have to forget about any APO refractor in 60-80mm and directly go with 100mm, and i asked in many groups there about how can i attach or place any Canon lens on my mount, and they always go with wrong answers such as how to connect lens to camera but i have connector or how to use ring holder on the lens, but my question was simple as how can i use the Canon lens alongside with guide scope whatever on the mount, they are all connected to cameras, but then i can't place them on the mount together and the answers are like going in circle or no direct answer, one or 2 gave good answer but the links are for stores i never use or can't use, so it remains like either i can't find a way to use my Canon lenses with guide scope so i must buy an APO refractor or just keep waiting the right answer with links to stores i can order from and can ship to my country.

For 100mm i was hoping to keep saving and then buy Takahashi FSQ-106 and never look back, if i managed to use my Canon lenses then i can wait for 100mm scope and so i will save for a Tak, if i buy Esprit maybe one day i will buy a Tak then i can't sell this Esprit and it will be a waste.

I am not sure about TS scopes, sounds good reviews but i don't see so so many images and results out of them to justify one, 2 or 3 nice images aren't enough, when i look around i barely can see many images from those TS scopes, so i try to avoid them and go with popular names instead [SW, Orion, ES, Celestron, WO,....etc]





I wouldn't bother with other lenses or scopes- At the 300mm focal length the Canon 300mm 2.8L would be excellent. If you need a tiny bit more focal length, say around 400mm, then get one of the Canon 1.4X teleconverters/extenders for very little image quality loss. All you need to do is to mount your guidescope (you don't say which) together with your camera (you don't say which, but presumably DSLR) on to a common mounting rail that can be held by your mount (you don't say which mount). In any event the mounting rail /plate will most likely be either of the Vixen or Losmandy style dovetail.

Use the lens tripod collar thread to screw the lens/camera combo on to the dovetail mounting plate and then do the same for your guidescope, except that you may need some guidescope rings etc, to help you mount and aim the guidescope. At a guess a 11 or 14 inch (common mounting plate lengths) mounting plate should suit your situation, although I would try to select the shortest plate to suit your gear to minimize overhang and center the mass better. That should get you started.

In the spirit of a complete answer, If you want something different, It may also be possible to mount the guidescope to the lens by dispensing with the lens tripod collar and replacing it, if you are lucky enough to get the exact size, with a rigid telescope mounting ring which also has some top screw threads for potential guidescope mounting. Also possible, and i've seen it done. but somewhat flimsy and I wouldn't recommend it, would be to mount ( a tiny) guidescope to the camera hot shoe.

Also to help extract the most out of your 300mm 2.8L lens it would be good if you have one of the newer model fullframe 5D cameras or 6D.

Best
JA

Last edited by JA; 10-07-2018 at 02:48 AM.
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Old 10-07-2018, 03:27 AM
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Striker (Tony)
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How about the sharpstar 65Q, I have one and will be testing it out this weekend.
https://www.astronomyalive.com.au/te...telescope.html
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Old 10-07-2018, 05:39 AM
TareqPhoto (Tareq)
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Quote:
Originally Posted by JA View Post
I wouldn't bother with other lenses or scopes- At the 300mm focal length the Canon 300mm 2.8L would be excellent. If you need a tiny bit more focal length, say around 400mm, then get one of the Canon 1.4X teleconverters/extenders for very little image quality loss. All you need to do is to mount your guidescope (you don't say which) together with your camera (you don't say which, but presumably DSLR) on to a common mounting rail that can be held by your mount (you don't say which mount). In any event the mounting rail /plate will most likely be either of the Vixen or Losmandy style dovetail.

Use the lens tripod collar thread to screw the lens/camera combo on to the dovetail mounting plate and then do the same for your guidescope, except that you may need some guidescope rings etc, to help you mount and aim the guidescope. At a guess a 11 or 14 inch (common mounting plate lengths) mounting plate should suit your situation, although I would try to select the shortest plate to suit your gear to minimize overhang and center the mass better. That should get you started.

In the spirit of a complete answer, If you want something different, It may also be possible to mount the guidescope to the lens by dispensing with the lens tripod collar and replacing it, if you are lucky enough to get the exact size, with a rigid telescope mounting ring which also has some top screw threads for potential guidescope mounting. Also possible, and i've seen it done. but somewhat flimsy and I wouldn't recommend it, would be to mount ( a tiny) guidescope to the camera hot shoe.

Also to help extract the most out of your 300mm 2.8L lens it would be good if you have one of the newer model fullframe 5D cameras or 6D.

Best
JA
I prefer if there are links or images f what you are talking about, as i am trying to imagine what you are talking about and i feel i couldn't get it.

Beside my Canon lens, i do have the following setup or equipment i will use for imaging:

Mount: Skywatcher AZ-EQ6
Camera for imaging: QHY163M [so no DSLR]
Guide scope: either ST80 or ZWO 60mm
Guide camera: QHY5L-II-M, i do have ZWO ASI385MC for planetary, can be used here too.
Filters: 3rd party LRGB and Optolong NB [Ha/Oiii/Sii] filters all at 36mm size inside 7x36mm QHY filter wheel

I am using EQMOD rather than Hand controller and still have some problems to perfecting my polar alignment, but all told me to do that which i am almost close using Polemaster, and just last time night i started to use stars alignment as many recommended me to use it to get to targets better, and also last time i tested guiding again as i wasn't good in using it in the past once or twice, i got targets i wanted but they are all noisy and not pinpoint stars and let's say bad amp glow with OIII exposures as i was using higher gain, but i do live in light pollution area anyway.

So i want a scope or lens that i can depend on for all filters if possible and not Achro that will force me only for NB, and also for focusing as with Achro i may need to focus for all filters while with a lens or triplet i may not need to focus for each filters, but maybe 2 or 3, better than focusing for 5 or 7 filters, and hope i can buy autofocus motor one day but i have to make sure my lens is giving me results i need.

I am still learning, but i like to have right or nice setup before rather than depending in very simple and cheap gear even if they will do a job, so that i bought an astro cooling camera and filters, so i have to skip ST80 then and use something better, someone showed me an image from a triplet scope with exposure less than what i did with my ST80 and it was no comparison, only Ha, the image from that triplet was way way amazing with better stars or more stars and better contrast, so maybe that triplet even for one filter can resolve better results than an achro, at the end many are going this way with imaging scope, hope i can test my lens first and then i can decide which another scope, but i feel i will wait much longer and save budget so i can buy a Tak and never look back.
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  #10  
Old 10-07-2018, 05:42 AM
TareqPhoto (Tareq)
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Quote:
Originally Posted by Striker View Post
How about the sharpstar 65Q, I have one and will be testing it out this weekend.
https://www.astronomyalive.com.au/te...telescope.html
I am sure it is a nice scope, but i saw better or another options more appealing, so i will pass this one, thank you!
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  #11  
Old 10-07-2018, 07:47 PM
JA
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Tareq
To avoid duplication or mis directs with suggestions, exactly what mounting hardware do you already have for your ST80 and ZWS60 guidescopes? Mounting rings, dovetails etc... Post a picture of both with their mount hardware attached.

Best
JA
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Old 10-07-2018, 09:35 PM
TareqPhoto (Tareq)
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Is that really necessary because i really think i will use one of them as a guide scope not both once i buy another scope or using Canon lens, the mounting rings are the same as they came with, stock one, you can see those from those pics exactly

https://astronomy-imaging-camera.com...m1-460x460.jpg

https://www.firstlightoptics.com/use...rtravel_80.jpg

For that ST80 i bought FLO dovetail so i can put it on mount, but i replaced the stock focuser to 2" CrayFord and that one doesn't have a place for inserting a finder, but why you asking to see those mounting rings or dovetails anyway?

Here are the focuser and dovetails i am using with my ST80, if you want i can take an image of whole setup for you, but it isn't the problem, i just need to add a new scope for imaging or using my current lenses.

https://optcorp.com/products/tpo-2-c...escopes-cf-crf

https://www.firstlightoptics.com/dov...-dovetail.html
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Old 10-07-2018, 11:06 PM
Wavytone
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Tareq,

Having watched your posts on CN as well as here I will call you out. You are like a butterfly, hopping from one daydream to another, but never actually making a decision to commit to buy gear and use it. Every time someone offers you one or more solutions you change your requirements (if they were ever defined).

In my country we have a phrase for such people: "Your eyes are bigger than your wallet". There is a rather less polite term, too.

Make up your mind, commit to some gear and start using it, or call it quits.

Last edited by Wavytone; 10-07-2018 at 11:21 PM.
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Old 11-07-2018, 12:53 AM
TareqPhoto (Tareq)
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Originally Posted by Wavytone View Post
Tareq,

Having watched your posts on CN as well as here I will call you out. You are like a butterfly, hopping from one daydream to another, but never actually making a decision to commit to buy gear and use it. Every time someone offers you one or more solutions you change your requirements (if they were ever defined).

In my country we have a phrase for such people: "Your eyes are bigger than your wallet". There is a rather less polite term, too.

Make up your mind, commit to some gear and start using it, or call it quits.
You are right, it is all the fault of my eyes, they are bigger than 40", so i will keep asking always until i am done, you may not like that or been bothered, but some wouldn't mind, at least i bought something after all, and the remaining are harder to decide, i don;t have same your rich level to just "Buy and use it and later change if necessary", i buy once, not to buy twice or buy and regret, so that i ask much more than anyone else, and some really understand it and don't mind it.

I did use my gear i have currently, but really i try to avoid to post results here or on CN, i post in facebook, even my worst results people like it and they encouraging me, while if i post in forums where most members have those high end or $$$$ gear i feel like all my results even the best of best aren't good enough, that is why i ask about gear so i can try to catch up or match one day, and i am almost in half of the road now, i don't need to have 3 mounts and 6-8 scopes and 4-5 cameras, also i don't to buy and test it and then decide later, i buy what i am 100% know it is the one i need or at least i will not replace later.

Call it whatever you want, if i didn't get answers from one place then i can get them from another, and about me changing always is because everyday i learn something new and see more images, this always have affect on my decisions, last year i was thinking about few items because i didn't know about anything else or didn't see reviews or enough images, but since then until now many things happened and i saw more images and read more reviews or more about items, so it is up to me to re-fine or change my decision whenever it is necessary, didn't know that changing my decisions and asking a lot will cause all that annoyance or harm, sorry for that and i apologize.
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Old 11-07-2018, 01:37 AM
JA
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Hello tareq,
Does your eq6 mount have the Vixen mount saddle or the dual Vixen/ Losmandy stylevmount saddle?

Best
JA
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Old 11-07-2018, 03:54 AM
TareqPhoto (Tareq)
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Hello tareq,
Does your eq6 mount have the Vixen mount saddle or the dual Vixen/ Losmandy stylevmount saddle?

Best
JA

Hello JA,

Mine has dual style saddle, it is AZ-EQ6 from Skywatcher.
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Old 12-07-2018, 10:41 AM
JA
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OK Tareq, you said you wanted to know how to physically mount both your Canon 300mm 2.8L IS USM lens and your guidescope to your mount. As you mentioned imaging, the suggested method is for use in equatorial and NOT Alt-Azimuth mode. It may seem like I'm being overly prescriptive (telling you how to suck eggs almost) , but that's what you wanted. This is A way to do it. There are others. One could improve the rigidity somewhat as I'll mention later. You can buy the components at various astro suppliers of your choosing.....

Best
JA

STEP 1. Take your lens and under the foot of the tripod lens collar you will notice a female thread. It is a 1/4-20 tpi UNC female (internal) thread.
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Last edited by JA; 12-07-2018 at 01:14 PM.
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Old 12-07-2018, 10:46 AM
JA
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STEP 2. Obtain a 1/4-20 socket head capscrew of appropriate length (probably in the 10 to 15mm length range), Stainless Steel is good as shown:
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Old 12-07-2018, 10:51 AM
JA
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STEP 3: Obtain a Losmandy Style dovetail plate which should suit your dual style Losmandy D / Vixen AZ-EQ6 mounting saddle. The shorter the plate the better so as to centralise the mass more- perhaps around 8 to 11 inch long (2 standard size lengths) - probably 11inch as things may get crowded on an 8 inch plate. The Bottom on the mounting plate is shown in the first image and the topside in the second image. This type of plate should have sufficient counterbore sizes underneath to house the head of a standard 1/4-20 sockethead capscrew so that it does not protrude from the counterbore recess.
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Click for full-size image (adm-dovetail-a1-1000x700.jpg)
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Click for full-size image (adm-dovetail-a2-1000x700.jpg)
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Last edited by JA; 12-07-2018 at 01:17 PM.
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Old 12-07-2018, 11:22 AM
JA
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STEP4: Notice that your guidescopes the GWO or ST80 have various mounting threads/ holes underneath. A web image of the GWO 60 is shown below and it has what I believe to be (based on manufacturer specs) a series of three 1/4-20 UNC female threads, as can be seen in the 2nd image taken from below the scope along the mounting bar that links the 2 telescope guide rings. You may be lucky able be able to use 2 of these 1/4-20 threads to mount the scope. One would not be ideal, but you could also drill the losmandy bracket to suit a second hole if required. It depends on the centre distance between the holes. This is something you should check beforehand (preferably in person) with the Losmandy plate supplier as there a differing sizes and hole distances available.
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