Opinions - New Askar 103mm APO triplet

[Elp]

Look forward to the comparison.

[Raum]

Hi,

After using the Skywatcher 200pds for a while (really dislike collimating it), I want to have a relatively portable refractor (compared to the newt) for mainly astrophotography. I use a modded canon70d, but plan on getting the imx571 cooled cam. I want to stay under 1000€, but if there is a bargain that could be made I could go to a max of 1500€, it needs to have a aperture of at least 80mm (4") and a fl of at least 400mm (without flattener/reducer) a faster scope would be appreciated coming from a newtonian. What would you guys prefer/recommend. I have the following scopes in mind, feel free to recommend other ones if they are better/more suitable to my criteria.

TS optics Apochromatic refractor AP 80/480 ED Triplet Photoline OTA = around 800€ without flattener

 

Tecnosky ED Triplet 80/480MM F/6 V2 = around 750€ without flattener

 

SVBONY SV550 APO Triplet Refractor OTA 80 F6 = around 900€ with flattener and guide scope

 

ts optics Apochromatic refractor AP 80/480 CF-APO f/6 FPL55 Triplet OTA = around 1200€

 

Tecnosky 80/480 mm FPL53 Apochromat - OWL Series = around 1200€

 

Askar 103 without flattener =  around 1300€

 

SVBONY SV550 APO Refractor Telescope Apochromatic Triplet 122mm F7 = around 1500€ without flattener, cheaper during deals

All of these are triplets (either FPL51 or FPL 53/55 (almost the same specs)).

Thx in advance

[Elp]

A lot of these scopes are very similar and some might be made at the same source factory, although they're getting better I don't think you can lump the SVbony within this class. A triplet will usually be better than a doublet but the scope will be heavier so it also depends what mount you have.

[Raum]

10 hours ago, Elp said:

A lot of these scopes are very similar and some might be made at the same source factory, although they're getting better I don't think you can lump the SVbony within this class. A triplet will usually be better than a doublet but the scope will be heavier so it also depends what mount you have.

Interesting, thx for the answer. They are probably made in mostly the same factory indeed. Don't the tecnosky (not owl version) and the sv550 have the same specs tho?

The FPL51 is of course worse then the FPL53 on the more expensive scopes, but does it matter that much when imaging? The pictures on astrobin look mostly the same for these scopes.

I have the eq6r, but I want this scope to be portable (for possible vacations) if possible. I don't know how much a refractor above 4" (100mm) would be portable tho.

[Elp]

14 minutes ago, Raum said:

portable

I wouldn't consider a 4 inch refractor portable. For most modern airlines it's too long for carry on but youd have to do some research, I wouldn't trust one in checked in luggage. For travel something in the 60-80mm range will be better.

Glass is a debatable topic, it all depends on the mating glass matching, their coatings, how well the scope is put together etc. It's difficult to assess from finished astro images as most are very heavily post processed with star tools to reduce issues. I know from my FPL53 doublets that they do star bloat around bright stars but it doesn't bother me.

From your list the TS Photolines are regarded well as I believe the Tecnoskys but the latter aren't widely available around here more so in the USA so you'll hear more about them on the CN forums.

[Stu]

13 minutes ago, Elp said:

I wouldn't consider a 4 inch refractor portable. For most modern airlines it's too long for carry on but youd have to do some research, I wouldn't trust one in checked in luggage. For travel something in the 60-80mm range will be better.

Glass is a debatable topic, it all depends on the mating glass matching, their coatings, how well the scope is put together etc. It's difficult to assess from finished astro images as most are very heavily post processed with star tools to reduce issues. I know from my FPL53 doublets that they do star bloat around bright stars but it doesn't bother me.

From your list the TS Photolines are regarded well as I believe the Tecnoskys but the latter aren't widely available around here more so in the USA so you'll hear more about them on the CN forums.

There are some 4” scopes which are carry on portable, but in the main I agree they are just a bit too bulky for carry on.

[Elp]

As an indicator, this is a stark illustration of the size difference, a WO Z61 (an excellent scope overall) and a Starfield 102 (also good but hasn't got the diverse use the former has, it is also a similar scope to those listed above), note these are fully closed positions:

[Raum]

23 hours ago, Elp said:

As an indicator, this is a stark illustration of the size difference, a WO Z61 (an excellent scope overall) and a Starfield 102 (also good but hasn't got the diverse use the former has, it is also a similar scope to those listed above), note these are fully closed positions:

Interesting, thanks a lot for the comparison.  Then I would probably get the 80/90mm triplet, those are quite a bit shorter (around 20cm/ 8inch) then the starfield. The only worry I have then is a portable mount. Any idea on those?

[900SL]

On 14/01/2024 at 02:09, Raum said:

Hi,

After using the Skywatcher 200pds for a while (really dislike collimating it), I want to have a relatively portable refractor (compared to the newt) for mainly astrophotography. I use a modded canon70d, but plan on getting the imx571 cooled cam. I want to stay under 1000€, but if there is a bargain that could be made I could go to a max of 1500€, it needs to have a aperture of at least 80mm (4") and a fl of at least 400mm (without flattener/reducer) a faster scope would be appreciated coming from a newtonian. What would you guys prefer/recommend. I have the following scopes in mind, feel free to recommend other ones if they are better/more suitable to my criteria.

TS optics Apochromatic refractor AP 80/480 ED Triplet Photoline OTA = around 800€ without flattener

 

Tecnosky ED Triplet 80/480MM F/6 V2 = around 750€ without flattener

 

SVBONY SV550 APO Triplet Refractor OTA 80 F6 = around 900€ with flattener and guide scope

 

ts optics Apochromatic refractor AP 80/480 CF-APO f/6 FPL55 Triplet OTA = around 1200€

 

Tecnosky 80/480 mm FPL53 Apochromat - OWL Series = around 1200€

 

Askar 103 without flattener =  around 1300€

 

SVBONY SV550 APO Refractor Telescope Apochromatic Triplet 122mm F7 = around 1500€ without flattener, cheaper during deals

All of these are triplets (either FPL51 or FPL 53/55 (almost the same specs)).

Thx in advance

I have the TS CF 90 APO. It's excellent. 

[Nik271]

Note that the rear 100mm of the tube is removable, so in that configuration the scope with contracted dew shield should be just 60-10= 50 cm long, so should fit in cabin luggage. My only concern for portability is the weight, about 6 kilos. I wish they made an FPl 53 doublet in the same body, 

[Elp]

47 minutes ago, Raum said:

portable mount. Any idea on those?

Check what other people are using, these two may struggle with an 80mm triplet:

1. AZgti in EQ mode, 

2. Skywatcher SAGTI,

If you've got the budget these will be way better:

3. Ioptron hem15 or higher budget hem27,

4. Zwo Am3 or higher budget Am5.

The ZWOs will be better than the ioptrons as they have hd drives on both RA and DEC, but the ioptrons are also good (I've got hem15) at slightly cheaper prices.

[SamAndrew]

First imaging light for my Askar 103. I threw caution to the wind and went for the 0.6 reducer.

Initial impression

1. There's minimal tilt straight out the box
2. Corner stars are reasonable considering I haven't adjusted spacing to account for my filters yet, looks promising given it's a refractor at F4. ASP-C sensor.
3. Median FWHM on that single sub is 1.84 * 1.88" = 3.46"
4. Mechanical quality and fit and finish is excellent.

I'll try and do a full review once I've got some complete images, but so far I'm happy.

First frame with a stretch, no calibration:

raw corners (looks like spacing adjustment needed to account for filters):

Corners once BXT applied (basically perfect, wouldn't expect anything less now ) :

Single frame, no calibration, BXT, Graxpert and a stretch:

[Stuart1971]

15 minutes ago, SamAndrew said:

First imaging light for my Askar 103. I threw caution to the wind and went for the 0.6 reducer.

Initial impression

1. There's minimal tilt straight out the box
2. Corner stars are reasonable considering I haven't adjusted spacing to account for my filters yet, looks promising given it's a refractor at F4. ASP-C sensor.
3. Median FWHM on that single sub is 1.84 * 1.88" = 3.46"
4. Mechanical quality and fit and finish is excellent.

I'll try and do a full review once I've got some complete images, but so far I'm happy.

First frame with a stretch, no calibration:

raw corners (looks like spacing adjustment needed to account for filters):

Corners once BXT applied (basically perfect, wouldn't expect anything less now ) :

Single frame, no calibration, BXT, Graxpert and a stretch:

That’s look pretty darn good, especially with a reducer, I bet it’s almost perfect with just the flattener…what did we all do before BXT,  I think that has revolutionised processing for many people…👍🏻

[Adam J]

8 minutes ago, Stuart1971 said:

That’s look pretty darn good, especially with a reducer, I bet it’s almost perfect with just the flattener…what did we all do before BXT,  I think that has revolutionised processing for many people…👍🏻

We spent time making sure our optics worked correctly...some of us still do as BXT cant generate detail out of thin air. 

Edited February 11 by Adam J

[Stuart1971]

4 minutes ago, Adam J said:

We spent time making sure our optics worked correctly...some of us still do as BXT cant generate detail out of thin air. 

No, but when you have spent an age of time trying to get that last bit of tilt out of your system, but still get a slight elongation in one corner, BXT can do wonders, and for some people who just can’t afford high end optics or mount, it’s  a godsend to get half decent images….

So it has its place in my book…

[Adam J]

20 minutes ago, Stuart1971 said:

No, but when you have spent an age of time trying to get that last bit of tilt out of your system, but still get a slight elongation in one corner, BXT can do wonders, and for some people who just can’t afford high end optics or mount, it’s  a godsend to get half decent images….

So it has its place in my book…

Its actually hardly ever tilt causing bad corners from what i see, its just the go to explanation, its much more often a problem with collimation a problem would normally result in the OTA being returned or tweaked. I can just see it that in the future when you get a new refractor with collimation problems the manufacturer will just say why don't you just use BXT.... 

The above looks more like an optical issue than a tilt issue to me. I would be doing a star test not "fixing it" with BXT. 

If an out of focus star test in centre field shows non concentric rings...I think it will, then it needs colimating as something has shifted in transport. Not sure if the cells on these are user colimatable. So maybe ask the supplier if this turns out to be the case. 

As its showing on the short side of the sensor then its also possible to rotate the camera 90 degrees, if it stays the same its tilt, if gets mush worse its colimation. 

It has its place as you say, but even a budget refractor should come well colmiated even if the polish / correction is not top notch and while fixing minor issues is great you should not convince yourself to accept less than what you paid for. 

Edited February 11 by Adam J

[SamAndrew]

I plan to do expensive scope without BXT vs cheap scope with BXT comparison  although I don't have much broadband data with the FSQ-106; given my light pollution most of my data is narrowband.

For 1/7th of the price the Askar 103 is looking good.

[Elp]

I've been reading the focuser may not be that strong holding an image train, anyone like to comment?

Also have you experienced pinched optics issues when imaging, I assume once the scope is acclimatised it goes away.

[SamAndrew]

I thought the focuser is excellent, one of the best I've used, no issue with a 2600MM + filter wheel.

The problem I had was the blue channel was much softer than the red and green; all the reviews I've seen have been OSC which I think will hide the issue because you'll focus to an average point for all colours, but when using mono and refocusing between colours it was very noticeable. I was probably expecting a bit too much for the 0.6x reducer. Shame as it was so well built, It would be fine for narrowband, I nearly kept it for visual use, but FLO were happy to accept the return. Plan to share my analysis once I get chance, the data is hard to process to an acceptable result.

[Stuart1971]

On 11/02/2024 at 23:25, Adam J said:

Its actually hardly ever tilt causing bad corners from what i see, its just the go to explanation, its much more often a problem with collimation a problem would normally result in the OTA being returned or tweaked. I can just see it that in the future when you get a new refractor with collimation problems the manufacturer will just say why don't you just use BXT.... 

The above looks more like an optical issue than a tilt issue to me. I would be doing a star test not "fixing it" with BXT. 

If an out of focus star test in centre field shows non concentric rings...I think it will, then it needs colimating as something has shifted in transport. Not sure if the cells on these are user colimatable. So maybe ask the supplier if this turns out to be the case. 

As its showing on the short side of the sensor then its also possible to rotate the camera 90 degrees, if it stays the same its tilt, if gets mush worse its colimation. 

It has its place as you say, but even a budget refractor should come well colmiated even if the polish / correction is not top notch and while fixing minor issues is great you should not convince yourself to accept less than what you paid for. 

that is certainly not a collimation issue shown, as the OP said its mote likely a reducer spacing issue, the star shapes tell you that quite obviously, i owned a Tak FSQ85 that was  basically crap, and had to go as the collimation was awful and these were the star shapes i got in the corners…really bad astigmatism

It’s the only scope on the market that you have to use two flatteners with and even then it’s not great….

Edited March 4 by Stuart1971

[Adam J]

9 minutes ago, Stuart1971 said:

that is certainly not a collimation issue shown, as the OP said its mote likely a reducer spacing issue, the star shapes tell you that quite obviously, i owned a Tak FSQ85 that was  basically crap, and had to go as the collimation was awful and these were the star shapes i got in the corners…really bad astigmatism

It’s the only scope on the market that you have to use two flatteners with and even then it’s not great….

The FSQ is a totally different optical design to this scope the effects of collimation errors are different. The issue with the FSQ85 is that it was never optically designed to cope with modern small pixel cameras., Unfortunately what your seeing here is quite typical. of this. 

[Elp]

Whoever sniped that offer scope was fast off the line. A good buy methinks.

[Calvin Klein]

On 05/03/2024 at 09:18, SamAndrew said:

I thought the focuser is excellent, one of the best I've used, no issue with a 2600MM + filter wheel.

The problem I had was the blue channel was much softer than the red and green; all the reviews I've seen have been OSC which I think will hide the issue because you'll focus to an average point for all colours, but when using mono and refocusing between colours it was very noticeable. I was probably expecting a bit too much for the 0.6x reducer. Shame as it was so well built, It would be fine for narrowband, I nearly kept it for visual use, but FLO were happy to accept the return. Plan to share my analysis once I get chance, the data is hard to process to an acceptable result.

I will be extremely keen to see your analysis results.  I was very excited about this scope and 0.6 reducer having just read every post and review I could - until I saw this.  I was thinking of using this combination with a 2600MM/EFW and Antlia Pr LRGB filters but am very concerned now with the performance of the blue channel.  As you say, all testing so far is with OSC.

[Stuart1971]

2 hours ago, Calvin Klein said:

I will be extremely keen to see your analysis results.  I was very excited about this scope and 0.6 reducer having just read every post and review I could - until I saw this.  I was thinking of using this combination with a 2600MM/EFW and Antlia Pr LRGB filters but am very concerned now with the performance of the blue channel.  As you say, all testing so far is with OSC.

It’s a very budget price for a reason, buy cheap and you will buy twice..😉

[Elp]

But if the colours dictated by mono LRGB filters are in focus they're in focus aren't they? If ones soft it'd be not in focus.