Megrez 90 Vs technosky 102ed

[Ratlet]

I've got one of the flavours of 102ed fpl53 doublets, however I've always been really keen on the megrez 90.  It just seems to be the a more flexible all round unit, you lose a little aperture but you gain something that is more grab and go and an even wider fov.

I've just seen one come up for a reasonable price and was wondering if I'm possibly just got a bit of new kit envy going on.

Does anyone have any experience with imaging with a megrez 90?  How is it for chromatic aberration?  For visual I've heard good things but am I likely to miss the 12mm of aperture more than any benefit of from imaging/ear give I don't frequently do it?

[Elp]

Think I've seen it. Just last week a used FLT91 sold for less than half price, that would have been a purchase. Don't know about the Megrez as they're older scopes.

Not sure how much a difference a triplet makes for visual as I believe the main correction of the third element is for one colour, you hardly see any colour fringing in a good doublet. Photographically you'd likely notice more of a difference, less star bloat maybe one.

[Ratlet]

Think the Megrez 90 is a doublet.

[Ratlet]

Jeepers though @Elp, is that the flt on eBay on the 19th?  That's an incredible price.  Bit concerned that they didn't show any images of the optics, but someone got a deal on that.

[Elp]

3 minutes ago, Ratlet said:

Jeepers though @Elp, is that the flt on eBay on the 19th?  That's an incredible price.  Bit concerned that they didn't show any images of the optics, but someone got a deal on that.

From a charity/pawn shop? Yes, an absolute bargain, though they took photos of everything but the most important thing, the optics.

Edited September 25 by Elp

[Elp]

Not sure on the whole Megrez line, they all seem to have different optics when people list them. There's one listed as fpl53 but the lens front doesn't mention it. If your 102 is anything like my Starfield (probably the same scope) then I don't think you'll get any benefit from another doublet, unless if you simple want a smaller scope.

[John]

I've never imaged but I did own a Megrez 90 for a while a few years back. It was a doublet which used an FPL-53 ED element, or at least mine was.

Quite a nice scope 🙂

One of the few that I've bought new but I did loose rather a lot on it when I decided to sell it a few months later, despite it being in practically mint condition 🙄

I moved to the Vixen ED102SS after that one and appreciated the additional aperture for my visual pursuits.

 

[TiffsAndAstro]

10 minutes ago, Elp said:

From a charity/pawn shop? Yes, an absolute bargain, though they took photos of everything but the most important thing, the optics.

I've seen some charity eBay's with close ups of the front of the scope. Dust cap is still on mind you.

I tend to think, charity? Doesn't know any better....but I'm wary in case it's actually deliberate

[Ratlet]

21 minutes ago, Elp said:

From a charity/pawn shop? Yes, an absolute bargain, though they took photos of everything but the most important thing, the optics.

That was my first thought as well.  That and it looks like it had sold previously but been relisted.

16 minutes ago, Elp said:

Not sure on the whole Megrez line, they all seem to have different optics when people list them. There's one listed as fpl53 but the lens front doesn't mention it. If your 102 is anything like my Starfield (probably the same scope) then I don't think you'll get any benefit from another doublet, unless if you simple want a smaller scope.

I'll need to have a look.  I wasn't aware there was a range of them. 

The scope is with ENS so I was going to see if they would part exchange.  The 102 is absolutely fantastic though.  I've had it out more than the dob, so it is a decision that would need a good think as I'd absolutely kick myself if I went down that route and found the image wasn't up to the same impeccable standard.

[John]

I thought the optics in my Megrez 90 were nice but the Skywatcher ED doublets (eg: ED80, 100, 120) are as good IMHO. In fact WO used the Synta 120mm F/7.5 objective in their Megrez 120 refractor. The instrument was  more "polished" than the Skywatcher ED120 but optically just the same.

I'd be surprised if a Megrez 90 offered anything performance-wise that the Technosky 102ed doesn't - most likely the latter will deliver more, as the aperture suggests it should.

 

Edited September 25 by John

[omo]

Consider also a Crayford focuser (albeit very pretty) for imaging, versus your current R&P

[paulastro]

On 25/09/2024 at 14:57, Ratlet said:

I've got one of the flavours of 102ed fpl53 doublets, however I've always been really keen on the megrez 90.  It just seems to be the a more flexible all round unit, you lose a little aperture but you gain something that is more grab and go and an even wider fov.

I've just seen one come up for a reasonable price and was wondering if I'm possibly just got a bit of new kit envy going on.

Does anyone have any experience with imaging with a megrez 90?  How is it for chromatic aberration?  For visual I've heard good things but am I likely to miss the 12mm of aperture more than any benefit of from imaging/ear give I don't frequently do it?

I've  owned a Megrez 90 (fpl53) and it was excellent, sharp, good contrast and no worrying CA - visually at least.  It was very well built and quite heavy for the size.  In fact I've also owned a Tecnosky 102ED F7 fpl53s, same as the FLO version.  I'd say the performance of the 90 was much like the 102s except for the difference in aperture.

Image wise, not much between them I can recall.  The 90 is a short tube so not a lot of room for balancing if you're  adding lots of imaging  bits onto it.  Also my Megrez 90 had a foot unit with a photo thread on it - no dovetail and rings.    Having said all this, I did like the 90 and have thought of picking one up if I found one at a good price.

[plyscope]

The Megrez 90 is a really nice telescope. I enjoyed mine for visual. I sold it when I moved on to a TSA 102. The Megrez 90 is around 570mm focal length despite being specified as 621mm.

Nowadays I think I would prefer the 102 ED. More aperture and better focuser.

https://www.cloudynights.com/articles/cat/user-reviews/megrez-90-fd-fluorite-doublet-review-r2769

 

 

[Elp]

9 hours ago, plyscope said:

The Megrez 90 is a really nice telescope

Are they all the same optics? I'm sure I've seen different ones, doublet, triplet, TMB...

[plyscope]

Well I am not familiar with all of them but as far as I know the Megrez scopes were all doublets between 80 and 120mm.

William Optics certainly made other telescopes using doublets and triplets with different names.

[Elp]

Maybe aftermarket confuses the matter. There's a TMB one listed on eBay ATM, says Megrez 80 on the focuser but the objective is a triplet.

[Ratlet]

13 minutes ago, Elp said:

Maybe aftermarket confuses the matter. There's a TMB one listed on eBay ATM, says Megrez 80 on the focuser but the objective is a triplet.

It's not helped by WO at the time calling to objective flourite when it was fpl-53

[Ratlet]

I'm going to leave it to fate.  I've messaged ens to see if they would consider an exchange.  But it'll be 2 weeks till I could do a trade as working.

I love the 102ED to bits but the Megrez is a perfect fit in my stable.  It'll mount on the azgti and az5 easily and will negate the need for me to get a grab and go.

I shall wait with baited breath lol.

[John]

54 minutes ago, Elp said:

Maybe aftermarket confuses the matter. There's a TMB one listed on eBay ATM, says Megrez 80 on the focuser but the objective is a triplet.

Some of the WO refractors used objectives made by the russian companies LOMO and LZOS. Thomas M Back designed a couple of those. Very highly prized like all TMB / LZOS / LOMO objectives.

[Shed9]

The Megrez with ENS is the 90FD variant but I'm guessing a newer one given it has 558mm fl on the front text.  The 90FD is definitely an FPL-53 air spaced doublet (to my knowledge at least).   The asking price is about right for a standard Megrez 90, let alone with a moonlite bolted on to its rear - don't dismiss this in the overall decision process.  Wouldn't hurt to call ENS to have a chat if you haven't already.   I've purchased old mirror blanks from them in the past and they offered to strip them before shipping which I thought was going a tad above & beyond - really helpful and they delivered what I ordered with no complaints from me.  An no, not affiliated with them at all, just a happy customer is all.

I have an older Megrez 80 doublet and whilst the 80 is a little simpler in the focusing department, the business end of the glass is certainly punching above it's weight.  WO scopes are really well made and that shows across the line.  I think Ed Ting did a video in the last year on the Megrez 90, probably worth a watch.

 

Oh, and the FLT91 on ebay this last month, that was me that bagged that one 😁.  It was one of those cash converter type of shops selling product on ebay.  I saw it on the Thursday, dropped an email to the seller and they responded quite quickly later that evening advising the lens was good and (more importantly) that they hadn't tried to clean it with a duster and Mr Sheen.  I took a punt and hit the buy button on the chance it was what it said it was.  I've given it the once over and it all looks good so far, not had the chance to fully check it with other commitments going on but no concerns at the moment.  The FLT91 came with the flattener 0.8x reducer, all necessary adapters and the slide base guide scope, with the original bag (an RRP of >£2350), so yup, an absolute purchase.

Edited September 30 by Shed9

[Ratlet]

24 minutes ago, Shed9 said:

The Megrez with ENS is the 90FD variant but I'm guessing a newer one given it has 558mm fl on the front text.  The 90FD is definitely an FPL-53 air spaced doublet (to my knowledge at least).   The asking price is about right for a standard Megrez 90, let alone with a moonlite bolted on to its rear - don't dismiss this in the overall decision process.  Wouldn't hurt to call ENS to have a chat if you haven't already.   I've purchased old mirror blanks from them in the past and they offered to strip them before shipping which I thought was going a tad above & beyond - really helpful and they delivered what I ordered with no complaints from me.  An no, not affiliated with them at all, just a happy customer is all.

I have an older Megrez 80 doublet and whilst the 80 is a little simpler in the focusing department, the business end of the glass is certainly punching above it's weight.  WO scopes are really well made and that shows across the line.  I think Ed Ting did a video in the last year on the Megrez 90, probably worth a watch.

 

Oh, and the FLT91 on ebay this last month, that was me that bagged that one 😁.  It was one of those cash converter type of shops selling product on ebay.  I saw it on the Thursday, dropped an email to the seller and they responded quite quickly later that evening advising the lens was good and (more importantly) that they hadn't tried to clean it with a duster and Mr Sheen.  I took a punt and hit the buy button on the chance it was what it said it was.  I've given it the once over and it all looks good so far, not had the chance to fully check it with other commitments going on but no concerns at the moment.  The FLT91 came with the flattener 0.8x reducer, all necessary adapters and the slide base guide scope, with the original bag (an RRP of >£2350), so yup, an absolute purchase.

Cheers for that shed.  I messaged them on Friday so I'll give them a call.  I think I'll be in the right ballpark price wise for a part exchange.  

I'll need to watch  Ed's video again.  I was desperately having a look over refreshing views to see if he had any images from it but from what I can tell he is eaa in mono (still no filter so will show CA).

I've spoken to the wife and explained to her that there is a non-zero chance I'll be going down to Birmingham at the end of next week lol.

[Ratlet]

Just back from his video and trying to call ens lol.

I completely forgot ed usually does astrophotography.  Quite happy he posted the satellite images as the single frames are less likely to show the CA.

I think the scope has a good spot in my stable.  I've got the 10" dob for faint fuzzys and the 90mm will be great for imaging and visual.  If I need something with a bit more reach than the 90mm I've got the 130pds (and won't have to sell it lol).

Now just hoping nobody else sees it.

[Ratlet]

Someone beat me to the punch lol.  Oh well, back to waiting!  At least I don't have a long drive to Birmingham and at the end of the day I still have the 102ED to look through and it is a delight

[Elp]

4 hours ago, Ratlet said:

102ED

Are you looking for something "easier" to take outside (less stress on the mind, smaller, lighter)? I know the 102 although not massive in refractor terms, is significantly larger than say a 90mm and below.

I ask because likely nothing below the 102 will "match" it, you'll still get very good views through a smaller scope, but I'm wondering what you're trying to gain.

Any other of the smaller WO scopes will do if you're simply looking to lighten the load with good optics Z61/Z71. Or if you're after a good price maybe the Askar 71F, I've been looking at it a while but it's too similar to my Z61.

[Shed9]

4 hours ago, Ratlet said:

Someone beat me to the punch lol.  Oh well, back to waiting!  At least I don't have a long drive to Birmingham and at the end of the day I still have the 102ED to look through and it is a delight

Ironically, it's entirely possible and likely that it was your post that sent people to look at it, and the subsequent sale.  The WO tubes are definitely nicely engineered OTA's however in hindsight I'm not sure you would see that much difference between the WO90 and your current setup.   They are not that uncommon coming up for sale though, not a closed door as such.