4” or 4.5” Refractor on HEQ5

[JonHigh]

Hi all, just following on from another post… I’m about to pull the trigger on the 102 triplet, an upgrade from my SW Evolux 82 doublet. However the 115 has been mentioned and has got my wondering if perhaps that might be a better bet, as this will be my only imaging scope for a long time to come! Both scopes are from Altair, both SFPL-53 glass so are basically the same. Only difference is size and weight. I have an HEQ5 mount with about 2kg+ of accessories to attach. I would be buying a reducer so that’s going to add more weight. Really don’t want to buy more stuff after this and just keep the equipment I have. Checking on the site the 102 comes in at about 6Kg whereas the 115 is about 8Kg. Presuming the reducer is about <1kg adding more weight. Will that 115 be pushing the mount to the red line? Would it be better to get the 102 making it easier on the mount and possibly better guiding therefore getting better images vs bigger aperture? Alternatively save some money and get a 102 doublet if image quality is almost the same (say within 10%) as a triplet and a RC6 or Newt to cover the bases? Hope this makes sense. 

Edited June 19, 2023 by JonHigh

[nfotis]

Adding a reducer may add weight but at the same time reduces focal distance, so it should balance eventually.

A HEQ5 easily handles a 102ED or triplet,  a 120 triplet may be starting to push it for long exposures (depends on good balancing).

If you are suffering from winds, I would avoid larger than 100mm triplet APO, or go to an EQ6-R class mount for better stability (it's quite heavier, though)

If you are using a pier and have protection from winds, this little mount can do amazing work

https://www.cloudynights.com/topic/618910-will-the-heq5-be-enough/

 

[JonHigh]

41 minutes ago, nfotis said:

Adding a reducer may add weight but at the same time reduces focal distance, so it should balance eventually.

A HEQ5 easily handles a 102ED or triplet,  a 120 triplet may be starting to push it for long exposures (depends on good balancing).

If you are suffering from winds, I would avoid larger than 100mm triplet APO, or go to an EQ6-R class mount for better stability (it's quite heavier, though)

If you are using a pier and have protection from winds, this little mount can do amazing work

https://www.cloudynights.com/topic/618910-will-the-heq5-be-enough/

 

Thanks for the link. Will have a read in a bit! Although my head is telling me the 102 my heart is saying 115. 🙄

[nfotis]

7 minutes ago, JonHigh said:

Thanks for the link. Will have a read in a bit! Although my head is telling me the 102 my heart is saying 115. 🙄

If I didn't already own the 102ED from SVBONY, I would be tempted by their incoming 122 triplet, but that's another story... 🙂

(I intend on using the money savings toward a monochrome sensor and NB filters instead)

 

[JonHigh]

20 minutes ago, nfotis said:

If I didn't already own the 102ED from SVBONY, I would be tempted by their incoming 122 triplet, but that's another story... 🙂

(I intend on using the money savings toward a monochrome sensor and NB filters instead)

 

That makes sense. Filters aren’t cheap either. What mount do you use? I found the EQ6r too heavy but the HEQ5 was much more manageable so ran with it. The jump from a ASI585 to a Cooled APS size sensor has completely destroyed it. And totally surpassed the limits of what the Evolux can do which is why I’m looking for a new scope. Just want to get the right one that still gives me the guiding and tracking performance I’m used to without undue stress on it. Also I would like to get the most out of the camera as it’s so capable. 

[Clarkey]

FWIW I am planning to move my 115mm Starwave triplet to my HEQ5 this coming season. I was using it on an AZ-EQ6 but I think it should be fine on the HEQ5 with a 60mm guidescope and camera / mini PC. I intend to use the larger mount for a larger scope (RC8 plus ST80 guidescope). My HEQ5 has been belt modded and also has new bearings / grease so better than stock. I expect it to be fine at this FL - but I have not tried it yet.

[nfotis]

4 hours ago, JonHigh said:

That makes sense. Filters aren’t cheap either. What mount do you use? I found the EQ6r too heavy but the HEQ5 was much more manageable so ran with it. The jump from a ASI585 to a Cooled APS size sensor has completely destroyed it. And totally surpassed the limits of what the Evolux can do which is why I’m looking for a new scope. Just want to get the right one that still gives me the guiding and tracking performance I’m used to without undue stress on it. Also I would like to get the most out of the camera as it’s so capable. 

 

Forgot to mention, I own a HEQ5 (bought used years ago, so not even a regular USB connection). Added a larger PrimaLuce Lab dovetail clamp, and I am slowly gearing up for adding a guide scope etc as soon as I get a cooled camera (for now I am doing some occasional planetary imaging - I have loaded it up to a C9.25, ADC, 2x Barlow and an ASI462 camera - when I'm not just using it for visual observation with my Skymax 180 etc)

 

[JonHigh]

On 19/06/2023 at 17:55, Clarkey said:

FWIW I am planning to move my 115mm Starwave triplet to my HEQ5 this coming season. I was using it on an AZ-EQ6 but I think it should be fine on the HEQ5 with a 60mm guidescope and camera / mini PC. I intend to use the larger mount for a larger scope (RC8 plus ST80 guidescope). My HEQ5 has been belt modded and also has new bearings / grease so better than stock. I expect it to be fine at this FL - but I have not tried it yet.

The SkyMax150 gives me no trouble at all on my HEQ5. Held Jupiter and Mars in place for about 2hours with zero drift last year. I wonder if  C9.25 might be pushing it a bit but I’m more in to imaging so I’m always thinking about load limits I guess. However SCT/Maks are more compact than a heavy long refractor OTA! 

[JonHigh]

The Altair Wsve 115 version apparently weighs in at about 8Kg (17.6 lbs) and 72cm with dewshield retracted, 88cm with dewshield extended before added anything on the back. So I am guessing I might have moment arm issues (being over 1meter in length once reducer, spacers and camera are attached) as well, plus about 10.5kg (23.1lbs) in weight or so. Really thinking the Wave 102 will be a better fit. Shorter, lighter and other than a slightly narrower FOV I’m unsure exactly what the real world difference will be in imaging as I’m not going to be using it for visual purposes. 

[vlaiv]

I'm firm believer in capability of HEQ5

Yep, that is 200mm F/6 OTA + 60mm guide scope on Heq5 balanced by 3x 5kg counter weights.

Now, that is experiment I would not repeat, but I did manage to take an image in that combination. Not the best image in the world, but image still ...

Here is HEQ5 in different configuration (sorry for poor quality images):

Yap, that is 100mm scope being used as side by side guide scope for 8" 1600mm RC scope. This time balanced only by 2x5kg - although they were pushed as far down as possible.

Heq5 if well adjusted / tuned / re-lubed can handle up to 12Kg of load for imaging without too much issues.

I would put 115 on my heq5 without any hesitation, especially since it's been additionally modded since above images.

[JonHigh]

Considering that’s not bad! but definitely agreed only experimental. 
I was toying with the idea about getting an RC6/8 with a Skywatcher 80mm guide kit and a good FPL-51 or 53 Doublet instead of the Triplet? Good to see the 8” RC works well! Only hesitation was collimating having only owned Maks and Reflectors! Still, there is no rush so having input from you all,  looking around and working it out before the season kicks off again it great, then a decision must be made!!! 

Edited June 20, 2023 by JonHigh

[pipnina]

2 hours ago, vlaiv said:

I'm firm believer in capability of HEQ5

 

Yep, that is 200mm F/6 OTA + 60mm guide scope on Heq5 balanced by 3x 5kg counter weights.

Now, that is experiment I would not repeat, but I did manage to take an image in that combination. Not the best image in the world, but image still ...

 

Here is HEQ5 in different configuration (sorry for poor quality images):

 

Yap, that is 100mm scope being used as side by side guide scope for 8" 1600mm RC scope. This time balanced only by 2x5kg - although they were pushed as far down as possible.

Heq5 if well adjusted / tuned / re-lubed can handle up to 12Kg of load for imaging without too much issues.

I would put 115 on my heq5 without any hesitation, especially since it's been additionally modded since above images.

I do find my HEQ5 a little variable. Some nights I am pulling RMS at 0.35 seconds, at its worst when there's any wind at all it'll end up around 0.6-0.7. Before tuning it was guiding above 1s.

I do agree it punches above its weight class however. Mine is also "overburdened" to the point where the 2 5kg weights provided are nowhere near sufficient to balance it. Yet it still performs well most of the time?

I think the big weakness as always is wind. My new refractor has a much smaller wind profile than my old 8-inch which was a lighter setup.

Ultimately I think weight is a far less important factor with mounts (unless you're way way overburdening them!) than their rigidity against the wind... Which may correlate with their weight rating but probably won't be exact. Manufacturers probably aren't being super scientific with their method of working out the max weight anyway!

[JonHigh]

I did hear that Sky-watcher changed their weight limits almost over night some time ago. So being slightly conservative isn’t a bad way to go as I’m sure they know people will overload the mounts and still attain good results making them better than they are??? A good engineer always adds time to a job so when it’s done earlier than expected… we’ll need I say more. Lol. 

[The Lapwing]

4 inch is tops for that mount I am afraid 

[JonHigh]

Thanks and yes. After doing a lot of research on the web, forums and club, it would seem that you are also correct. I just want to get the best images without pushing the mount anywhere nears it limits. So i will be getting an Altair Wave 102 triplet in a couple of weeks time with either a .8 reducer and/or 1x flattener. Really looking forward to it and the season to come! A healthy jump from my Evolux 82 which incidentally has served me very well! It’s a brilliant scope for what it is! 

Edited June 25, 2023 by JonHigh

[The Lapwing]

On 25/06/2023 at 14:51, JonHigh said:

Thanks and yes. After doing a lot of research on the web, forums and club, it would seem that you are also correct. I just want to get the best images without pushing the mount anywhere nears it limits. So i will be getting an Altair Wave 102 triplet in a couple of weeks time with either a .8 reducer and/or 1x flattener. Really looking forward to it and the season to come! A healthy jump from my Evolux 82 which incidentally has served me very well! It’s a brilliant scope for what it is! 

An excellent choice, excellent value for money too, amazing really what you can buy for the money these days 

[JonHigh]

Thank you. Bought the Altair Wave 102  and very pleased I didn’t go for the 115. The 102 fits the HEQ5 just right.

[ollypenrice]

Late to the party but I think you were bringing a visual observing perspective to an astrophotography purchase. In considering the two scopes, what matters isn't aperture but field of view and image scale in arcseconds per pixel. The difference in FL is not enough to make a very significant difference to resolution of fine detail but it is enough to restrict your field of view. I think you made the right choice because you'll notice the extra FOV far more than you'll notice any miniscule loss of resolution.

Choosing a scope is like picking out a lens from your camera bag: nine times out of ten your first though will be, 'What focal length do I need for this shot?'

Olly

[JonHigh]

On 21/07/2023 at 15:31, ollypenrice said:

Late to the party but I think you were bringing a visual observing perspective to an astrophotography purchase. In considering the two scopes, what matters isn't aperture but field of view and image scale in arcseconds per pixel. The difference in FL is not enough to make a very significant difference to resolution of fine detail but it is enough to restrict your field of view. I think you made the right choice because you'll notice the extra FOV far more than you'll notice any miniscule loss of resolution.

Choosing a scope is like picking out a lens from your camera bag: nine times out of ten your first though will be, 'What focal length do I need for this shot?'

Olly

I guess as I’ve bought it. Lol. Thanks for your comments and you are definitely right in what you say. I come from a photographic background which has helped a great deal but astrophotography is not normal everyday photography! With the help of Sky Safari and CDC showing me exactly what the FOV will be with the  scopes and camera combination pushed me towards the 102. Glad I did having now added all the extras, it’s not a light rig! 

Edited July 23, 2023 by JonHigh

[JonHigh]

On 19/06/2023 at 22:27, nfotis said:

 

Forgot to mention, I own a HEQ5 (bought used years ago, so not even a regular USB connection). Added a larger PrimaLuce Lab dovetail clamp, and I am slowly gearing up for adding a guide scope etc as soon as I get a cooled camera (for now I am doing some occasional planetary imaging - I have loaded it up to a C9.25, ADC, 2x Barlow and an ASI462 camera - when I'm not just using it for visual observation with my Skymax 180 etc)

 

Been considering a PrimaLuce dovetail Clamp to replace the stock one as the Losmandy bracket looks a bit thin on one side as it’s curved. Seems okay and holds the scope fine but it’s holding ££££‘s of equipment. I do realize that it is rated to hold a lot more weight so am I worrying unduly?

[nfotis]

10 hours ago, JonHigh said:

Been considering a PrimaLuce dovetail Clamp to replace the stock one as the Losmandy bracket looks a bit thin on one side as it’s curved. Seems okay and holds the scope fine but it’s holding ££££‘s of equipment. I do realize that it is rated to hold a lot more weight so am I worrying unduly?

 

I don't know, my HEQ5 mount is an old one, which didn't even offer a Losmandy dovetail clamp, only a Vixen-compatible one - and it was causing aesthetic damage to dovetails with its screws, which were half-broken.

So, my new clamp was a major (and rather costly) upgrade, since it now permits me to mount a C9.25 with its fat dovetail etc. I was handling it with my original clamp and an alternate Vixen dovetail, but it didn't feel very secure (it was quite steady, though, if you let the screws dig into the dovetail  - the current friction version should be quite improved).

 

[JonHigh]

Thanks for the reply. I must admit I was pleased to see that Skywatcher had updated the saddle closer to the 6r when it came around to my purchase as the photos I saw were of the original one. But sure, had it have been the original, I think I would have upgraded it without question.

[ollypenrice]

This kind of hardware, bought new, is very expensive and out of all proportion to the quality of the final image. I'd be inclined to devise a failsafe additional strap of some kind. I've concocted all kinds of variants on this theme.

Olly

[JonHigh]

Sound advice but knowing my luck the scope would come off, swing out, taking the mount with it! I think I might look at updating my photography insurance policy!!! 😂 

Edited July 24, 2023 by JonHigh