6" f/4 challenge: QUATTRO 150P, Stellalyra + corrector or something else?

[GTom]

Looking for recommendations on a short-tube Newtonian for photography. F/4 sets quite a few challenges I know. Still I would like to venture in this territory because this speed would be more forgiving to the mount & guiding and also more travel friendly being basically airline compatible. For camera I'd start with a modified Nikon D5100 with this scope.

So far the candidates:

Stellalyra probably with the GPU corrector

RVO Horizon

QUATTRO 150P with its own corrector, limited to approx 4/3rds sensor size (less than APSc) but super-fast f3.45! Expensive at first.

TS Photon CC needed

Altair,  again, CC needed

 

 

Edited June 13 by GTom

[Clarkey]

I would suggest that all of them would require money spent for decent results. In general, the focusers tend to be poor and need replacing. (I believe there are two versions for the Quattro, but it seems more recently the rubbish one comes as standard). The TS / RV and SL are probably all GSO variants and have all the same issues. On top of this the secondary spiders are not really up to the task. I have the TS version, but by the time I added a decent CC and focuser it was getting up towards £1000. Personally, I would suggest getting a decent astrograph to start with and save yourself the hassle. Have a look at the videos from Cuiv starting here:

 

 

[GTom]

Yeah, suspected that. Was wondering if any "localized versions" (RVO, Altair) could save me e.g. replacing the focuser.

[Clarkey]

5 minutes ago, GTom said:

Yeah, suspected that. Was wondering if any "localized versions" (RVO, Altair) could save me e.g. replacing the focuser.

I would add that the 150mm f4 scopes regularly come up second hand. You could consider a used one and spend the difference on a Steeltrack or similar focuser. (The ST does take a bit of fettling to fit a 150mm scope). Once 'working', these scopes can give very good results - but they are not too good out of the box,

[GTom]

Yupp, exactly that 😅. The idea came from me seeing two second hand kits.

[Backyardscope]

I have the Quattro 150P, its an excellent scope, one of best purchases for a long time. It may take time to tune it if you do not have any experience in fast newtonians.

The video above, truth being told; he over exaggerates the issues with the telescope, surely someone with an ounce of common sense, if you received a scope with all these issues, you would send it back!

I have done no modifications on the telescope to date apart from change the spider to a CNC version, which I bought from a supplier which was not from @FLO, works just as good compared to the Backyard Universe version. The only reason for changing, I liked the reflection of colour in the spikes, otherwise the standard secondary spider would have sufficed as I managed to image quite well without one initially.

Never needed to tape the focuser around, never needed to paint back of the secondary as the one supplied is already blackened.

Nothing wrong with the linear power focuser, these focusers are shipped with UK stock I believe, the normal dual speed focusers are shipped in the Americas. Some of my images are on the Sky-Watcher Website prior to any modifications, including the spider.

No problem with secondary & primary collimation. Secondary collimation stays quite well corrected and no image shifting. The only thing people need is having patience to tune it and get the spacing correct with the coma corrector. 

You have a lot of scope for £500 inc. a decent Coma Corrector with ED Glass.

Edited June 14 by Backyardscope

[alacant]

12 hours ago, GTom said:

the candidates:

Apart from the Quattro, all the other telescopes you list are the same; a re-marketed gso model. The problem with these is the ridiculous positioning of the secondary, leaving the focal plane here:

And so impossible to mount cameras without tilt, let alone balance.

The Quattro you'll find regularly for sale on the pre-owned market due to quality control issues. Or lack thereof. It took us three attempts to find one with optics and/or focuser which were usable.  It depends very much from which batch you purchase. Contrary to the mis-information, the Quattro produces a flat field over aps-c. The only affordable model for full frame we've witnessed is the 203mm or 208mm f3.9 ES (Bresser) with the 85mm secondary. Full account for the Quattro 150p  here.

In our hands-on experience, the only Newtonian f4 which works out of the box is the TS UNC or ONTC.

Cheers and HTH

Edited June 14 by alacant

[Backyardscope]

37 minutes ago, Clarkey said:

I would add that the 150mm f4 scopes regularly come up second hand. You could consider a used one and spend the difference on a Steeltrack or similar focuser. (The ST does take a bit of fettling to fit a 150mm scope). Once 'working', these scopes can give very good results - but they are not too good out of the box,

Mine was fine out of the box, others can differ!

[alacant]

4 hours ago, Backyardscope said:

Mine was fine

Absolutely. If you get a good one, they're superb. Fast, bright enviable...

Alas, if not, a nightmare!
Cheers

[Backyardscope]

Another point to add into this thread, one must remember anything below f/5 in reflectors, quality of components are paramount. Errors are magnified many times over. That's the reason why I say they are more suited to people with experience with fast newts. 

[GTom]

Will be a quick learning curve for me as I was all in refractors so far, haven't owned a Newtonian in the past 15 years. Needs must, can't go slower as this would be a travel scope too, anything longer wouldn't fit a cabin bag.

If I have to resort to visual only in the first few trips, so be it, 6" Newt. will most likely give far better visuals than my 3.5" refractor...

[Backyardscope]

2" sight tube for secondary collimation and a chesire eyepiece for the primary. Forget the laser method.

[Rallemikken]

15 hours ago, GTom said:

Stellalyra probably with the GPU corrector

I have this newt, and got this https://www.firstlightoptics.com/coma-correctors/skywatcher-coma-corrector.html

 coma corrector. Gives perfect stars all over, even with my Canon 5D MkII fullframe. Focuser seems solid and stable. Primary mirror cell not so good. DO NOT thighten the three supporting screws in the bottom. And there are some light leaks. Small details. All-in-all, a good scope.

[Albir phil]

15 hours ago, GTom said:

Looking for recommendations on a short-tube Newtonian for photography. F/4 sets quite a few challenges I know. Still I would like to venture in this territory because this speed would be more forgiving to the mount & guiding and also more travel friendly being basically airline compatible. For camera I'd start with a modified Nikon D5100 with this scope.

So far the candidates:

Stellalyra probably with the GPU corrector

RVO Horizon

QUATTRO 150P with its own corrector, limited to approx 4/3rds sensor size (less than APSc) but super-fast f3.45! Expensive at first.

TS Photon CC needed

Altair,  again, CC needed

 

 

Hi I recently bought 150 quattro,I live in Spain and got mine from Germany the focuser was the better one so did not change that,I did replace the spider, and fitted primary mirror mask from backyard universe.Had no problem with fitting them.i.also made a foam bung that fits behind the main mirror to stop light leaks.All in all no problem and it's a great fast astrograph 👍

[dunc]

7 hours ago, alacant said:

...

In our hands-on experience, the only Newtonian f4 which works out of the box is the TS UNC or ONTC.

Cheers and HTH

Just to interject with my experiences. I had a Skywatcher 150 PDS for a while then upgraded for a better focuser and mirror set.  I got a TS1506 UNC but eventually had to replace the mirror cell, the standard one wouldn't let me collimate even after lots of trying and tweaking and a Concenter, Advanced Cheshire, cameras, lasers, swearing. In the end I 3d designed and printed a new mirror cell with decent springs and knobs and now its a fantastic scope which is easy to collimate and holds it.

[GTom]

On 14/06/2024 at 09:05, Backyardscope said:

I have the Quattro 150P, its an excellent scope, one of best purchases for a long time. It may take time to tune it if you do not have any experience in fast newtonians.

The video above, truth being told; he over exaggerates the issues with the telescope, surely someone with an ounce of common sense, if you received a scope with all these issues, you would send it back!

I have done no modifications on the telescope to date apart from change the spider to a CNC version, which I bought from a supplier which was not from @FLO, works just as good compared to the Backyard Universe version. The only reason for changing, I liked the reflection of colour in the spikes, otherwise the standard secondary spider would have sufficed as I managed to image quite well without one initially.

Never needed to tape the focuser around, never needed to paint back of the secondary as the one supplied is already blackened.

Nothing wrong with the linear power focuser, these focusers are shipped with UK stock I believe, the normal dual speed focusers are shipped in the Americas. Some of my images are on the Sky-Watcher Website prior to any modifications, including the spider.

No problem with secondary & primary collimation. Secondary collimation stays quite well corrected and no image shifting. The only thing people need is having patience to tune it and get the spacing correct with the coma corrector. 

You have a lot of scope for £500 inc. a decent Coma Corrector with ED Glass.

May I ask a favor? Could you (or any other Quattro 150p owners) provide me a number for the LENGTH of the OTA? Really unprofessional from the manufacturer and all the retailers that they dont give proper dimensions... I need to fit the little fellow in a cabin bag! (55-56cm) Is it possible to remove the white rim on the top of the OTA? That and the main collimation screws could save enough length...

Edited June 15 by GTom

[alacant]

10 hours ago, GTom said:

LENGTH of the OTA

55cm. The dust cap adds 1cm and the locking screws a further 1cm, so 57cm total. Remove the locking screws anyway and simply use m5 retaining screws instead (to retain your extra up-rated springs) which fall flush with the mirror cell. So 56cm is looking good for carry-on.

 

Recommendation: fit one of these kits before travel.

10 hours ago, GTom said:

possible to remove the white rim on the top of the OTA

Yes, the last four screws before the open end of the tube. BUT... if you have the original spider, remember to loosen -at least two at right angles of- its tube retaining screws before removal, otherwise the tube will distort upon removal.

Cheers, happy travels and HTH

 

Edited June 16 by alacant

[GTom]

Magic,thank u!

[Backyardscope]

Good kit that is  Use the spider and it's nicely machined.

[Ardsley Astro]

I'm confused what to do now, I was going to go for the 150P-DS and then at a later stage get a Coma corrector. Looking at the CC supplied with the Quattro alone its priced over £250. Then there is the focuser. If the ones supplied in the UK have the decent focuser then I wont have to replace that either at great expense. This makes me lean towards the Quattro. What worries is me the collimation. I've collimated my Celestron 130EQ and my Sky-watcher 130P, but is the jump to F4 (F3.45 with the CC) really that much more difficult? The other option is going for the Stellalyra 6" F5 and then maybe the cheaper £99 CC but if I'm buying separately I would like to buy and use the scope without the CC first, so then I have the question of will it prime focus a DSLR.

[alacant]

3 hours ago, Ardsley Astro said:

the collimation

There's a lot of rubbish/misleading/wrong information about collimation of Newtonian reflectors, none more so than the horror stories surrounding f4. In fact they're all collimated in the same way. All low end instruments will have something wrong at the focal plane, no matter how careful you are.

If you want perfection and/or a Newtonian (any Newtonian) which works out of the box, you're going to have to begin at a much higher price point. 

 If it's any help, the German importer we deal with relays batches of the Quattro -with the proper focuser-  to ovl, who supply some UK retailers. Take a chance?

Cheer an HTH

 

 

 

Edited Monday at 17:53 by alacant

[Backyardscope]

Patience helps and the correct tools. I used the quattro initially with a DSLR with the CC without any focusing issues. 

However I do recommend buying a low profile t ring and setting the spacers yourself instead of using a standard t ring, as the spacing seems to be a bit finicky.

Edited Tuesday at 06:14 by Backyardscope

[ollypenrice]

If you consider the whole of the the word 'travel' rather than just the bit about the aeroplane, I wonder how travel-friendly an F4 Newt is likely to be? An instrument which is very sensitive to fine tuning is going to need fine tuning at your destination.  How much of your holiday time will that take? How much imaging time will be consumed? Does anybody know? I don't, but I think it's a big risk and not one that I, personally, would want to take.

Olly