TS-Optics 6" f/12 Cassegrain Teleskop, very first impressions.

[Greymouser]

Well had it out for a little while tonight, battling the Dew and am left with mixed feelings.

The second image is tonight outside in the back garden, not the best photo, but there you go. I knew I would be fighting the dew, but thought it would be a good test, which it was, with the primary mirror staying dew free, but the secondary starting to dew up after a while, which whilst disappointing, was to be expected I suppose with 95% humidity. I also had real problems with my eyepieces, so will have to dig out my eyepiece dewstrap, though not for a while for the forecast is awful for ages. I struggled with focus at first, then realised what the spacers were for. Doh!

Anyway, it seems to be a good scope, the focuser is half decent, but not as good as the Skywatcher ED80 one, I would say, which is surprising when I consider that many think that is poor. ( Mine is good on my ED80 though. ) I wandered round for a while and settled on M42 in the end, which was nice. Good contrast, but not that good a view of the Trap, certainly I got better with my C5 when last I looked, but the seeing is not good here tonight, imo. At least I could easily see them. Hard to judge night to night, at least for me with my lack of experience and the dew on the eyepieces, so I will have to see them side by side when next the opportunity arrives.

The OTA is of a good size and weight, ( they say 5.4 KG, I will weigh soon, ) easy to manage, even for me with my frozen shoulders and a damaged back. It fits very nicely on my Evolution mount, which handles the OTA very well, but balance was not as easy as the C5 is, to achieve. For some reason too, there was more vibration when focusing, which I do not really understand, but I will figure it out and improve it. I do think the focuser needs replacing with a better one though when it can be afforded.

Next quality control. As stated on another thread I have read tonight, whose responsibility is it? Manufacturer; retailer or distributor? Perhaps a combination of all three. Well this scope has two combined as it is a TS scope, bought in this case from TS, so there is little excuse for QC faults. The thing is though there is a fault I think. Two in fact, firstly the focuser feels loose and not well made, not surprising maybe considering the price point: 399 Euros. Maybe I will find a way to fettle it, maybe it is what it is and it needs upgrading. Secondly, whilst tonight was only the second time out of its box for me,  I see a potential problem with the primary. I saw nothing wrong with it in daylight, seemed clean and fine, but tonight as I was checking for dew closely, ( after I had finished my little session, )  I shone a bright white light down there, which showed me little speckles on it like dust. When I came in I allowed the OTA to settle out, warm up etc, then looked down the end with the bright white torch, which again showed the dust like speckles, which to my mind just should not be there on a brand new scope. Worse still there appears to be a very small ' growth ' like thing ( fungus? ) about 2/3mm across or so. I tried to photograph it, but is does not show up on the photo, so may try again tomorrow.

I have a problem, if it was the excellent FLO I bought it from, I would ask for a replacement, but with this coming from Germany, I am somewhat reluctant. Even more so as the companies customer service is unknown to me, how to prove the fault was not caused by me? Never mind that the fault is minor and doesn't seem to affect performance, as well as being easily solved, maybe. 

Overall I am in two minds about this scope, it is  a good design, but to be honest, with my very first impressions, I prefer my C5. Of course this was cheaper than my C5, but it is not as versatile and the quality control is not as good as might have been hoped. The C5 has a corrector plate that dews up fast, but even this scope has a secondary which dews up after a bit, so is not immune to dew. The C5 is also easier to solve the dew problem on. Of course this may have no dew problems most of the time, only being a problem in high humidity. Not sure I will be buying from Germany again.

It would have been so much easier if FLO sold classical Cassegrain of course!

[johninderby]

I was wondering how the quality control of the 6” would stack up to the 8”.

After checking on the TS website I do notice that the focuser is not the same as the 8” which is rather good but is a more basic focuser. Also note the mirror is quoted as 96% refectivity not the 99% of the 8”.  Still I would expect it to perform quite well and it is keenly priced. Have you checked the collimation yet? Hopefully you will get some better seeing soon. 

Recently had the 8” out and water was running off the OTA and both the eyepiece and finder were dewing up but not the secondary. Hmmmm.

Here is a photo taken down the tube and you can see what the mirror of the 8” looks like.

Edited January 20, 2020 by johninderby

[CraigT82]

If there is one thing I've learned about telescopes, it's never study the objective with a torch!

Even the newest shiniest mirror will look filthy under bright torchlight. 

[dweller25]

Hello @Greymouser,

That looks like a nice scope and it’s certainly very good value for money.

I was also out last night with my C6 and as I don’t live two far from you was similarly affected with poor seeing and heavy dew, so I am not surprised your secondary dewed up - all my open fronted scopes have suffered from this issue and I still had to use a dew shield on them to avoid the problem.

The focuser can be adjusted if you are handy, see here......

https://www.cloudynights.com/topic/647093-fixing-my-gso-cassegrain-focuser/

The mark on the primary - could it be a loose paint fleck ??
If it is mould then pointing it at the sky for a good dose of UV will kill it - or you could speak to TS and return it - they have excellent customer service.

Don’t think the dust specs on the primary will be an issue and as the tube is open the dust will get worse - my advice is to not point a torch down there.

Hope that helps.

 

 

 

Edited January 21, 2020 by dweller25

[Greymouser]

10 hours ago, dweller25 said:

The mark on the primary - could it be a loose paint fleck ??

No, I am pretty sure it is not, but will check again. I will wait for the sun again to give it a blast of UV, though that wait could be quite a long one...
I couldn't see any problem with the optics when I opened it, nor until I shone the bright, very white torch down the end, perhaps a mistake that. I am not bothered about the dust, that is normal with an open OTA, but the possibility of mould made me shiver a little. I will check as soon as I can.

@johninderby I agree the dew on the secondary was surprising, but I did check the humidity with my electronic thermometer and it was 95% and 1.7 degrees C, so perhaps not that surprising really. I have read of several having similar problems with Newts too. Easy to solve that one though, with a home made dew shield. The view down your OTA looks very similar to mine. Your comment about the reflectivity, makes me wonder just where different scopes stand on this, because not all comment on it. I mean just where does Celestron SCT, or Skywatcher mirrors stand on it? It is not important, just interesting for comparison.

I want this scope to work and fit in with my stable, alongside my C5 at F6.3.

Edited January 21, 2020 by Greymouser

[johninderby]

Can be  difficult to properly evaluate a new scope if the weather doesn’t co-operate. Hopefully with a few outings you will get a better feel for it.

The Celestron SCt XLT coatings are about 95% reflectivity so very similar although the TS has quartz mirrors so will be more stable during cooling which means you should find you don’t have to wait for tt to fully cool down to get good views.

Edited January 21, 2020 by johninderby

[Greymouser]

On 21/01/2020 at 22:12, johninderby said:

Hopefully with a few outings you will get a better feel for it.

Hopefully you will be right, whenever the weather plays ball again.

Unfortunately, events could overtake me and at the moment I am regretting buying this, even before properly evaluating it, as I think I need to trim my flock down, quite drastically maybe. We will see.

[Thommy]

I agree with the others that you should test it on several nights to see if your findings are consistent.

TS are known for their first-class service. If I were you, I would contact them and explain the problem.

/Thommy