Redcat 51 - focusing issue. What am I doing wrong?

[Adam J]

10 minutes ago, teoria_del_big_bang said:

Unfortunately you are right and some people do not see to have a conscience at all.
Over the years I have become quite distrusting of people I do not know and wary wary of buying 2nd hand, although to be honest the much maligned Ebay is actually very good at getting your money back in cases like this, but still not bought any astro gear off them as generally just too expensive anyway.
That just seems to be how the world has gone over the past years, too may people just willing to con others for monetary gain.
I think what makes buying 2nd had astro stuff open to abuse is that pretty much all genuine Astronomers (whether visual or AP) are very trustworthy (well seems to me so far) and all genuine Astronomers seem to look after their gear extremely well and in cases something is wrong or even suspected wrong with the gear they are selling are very honest.
So as a result I tend to trust them more than I probably should, fortunately buying mostly of SGL and on add item off ABS have been well pleased with my purchases.
So when this sort of thing happens and the seller just turns their back on any issues it is quite shocking.

I think I will continue to stick to 2nd hand from SGL mainly.

Steve

I don't know Steve its happened to me a couple of times, someone on ABS literally sold me a filter wheel with a obviously stripped thread on it and I have received a scratched filter, again ABS. 

In both those cases the sellers refunded. But recently I came to the conclusion that I wont ever buy an expensive item like a mount, scope, or camera without seeing it working first. My biggest one i fear is buying optics and they are hit and miss new let alone second hand, the scope itself can look great and be utter trash, there is just no way to test it at a motorway service station meetup on the M1. 

Adam 

[Adam J]

3 minutes ago, powerlord said:

I think the forum community helps. A seller knows that if he is dishonest on here, folk will hear about it. And on ebay, you get hit with bad ratings, etc. On ABS, you get banned. so what, you use another email address.

I'll certainly be much much more careful in the future buying from ABS.

stu

This is exactly why I really disagreed with the change in policy allowing people to sell items on this forum without gaining reputation first. But I suppose that I can and do look at post count when I buy from someone on here. 

Adam 

[powerlord]

7 minutes ago, Adam J said:

This is exactly why I really disagreed with the change in policy allowing people to sell items on this forum without gaining reputation first. But I suppose that I can and do look at post count when I buy from someone on here. 

Adam 

that's what I do. And of course, you can maybe search for posts from them about the bit of kit, etc.

Anyway.. back to the topic at hand...

My thoughts are that the optics were pinched, and are not not pinched. which is good.

But that doesn't help the curvature. My finds are the same as Georges = 30%. kinda rubbish. I found same thing. about 30% on subs, but stacked it was down to 18% (?).

Compared to my canon 300mm which is nearly totally flat.

So, I think next thing to do is tweak that rear corrector. I assume that is the lens that was removed in later models as I thought it was a 2 sets of 2 lenses (2 at front, 2 in middle). whereas if that's true, this has one at the back too.

So I'll try making small adjustments to the distance of it from the middle lens and see what effect it has.

stu

 

[teoria_del_big_bang]

11 minutes ago, Adam J said:

I don't know Steve its happened to me a couple of times, someone on ABS literally sold me a filter wheel with a obviously stripped thread on it and I have received a scratched filter, again ABS. 

In both those cases the sellers refunded. But recently I came to the conclusion that I wont ever buy an expensive item like a mount, scope, or camera without seeing it working first. My biggest one i fear is buying optics and they are hit and miss new let alone second hand, the scope itself can look great and be utter trash, there is just no way to test it at a motorway service station meetup on the M1. 

Adam 

Very true, and regarding optics it is very much hit and miss, often the seller may not be aware of the issues if not experienced. 
I bought my Esprit 2nd hand so not exactly cheap and did go to the guys house and take a good look, but I had no idea what to check. I seemed to have been lucky and after 3 years without any optical issues I had it recently fully serviced at RVO including a Zygo test and all came back good except needed a good clean of outer lens.
But even if you do this then a week or so later there is no guarantee the seller will return the money if there are any issues found and a repair could end up making it no cheaper than new.

I guess at least buying new gives you a lot more peace of mind regarding repair or refunds.

Steve

[newbie alert]

2 hours ago, Adam J said:

You really must report him to ABS they look very dimly on this type of behaviour and will ban him. 

Adam 

People knowingly sell duff items on here also...  It's out of order but it happens

[newbie alert]

50 minutes ago, teoria_del_big_bang said:

Very true, and regarding optics it is very much hit and miss, often the seller may not be aware of the issues if not experienced. 
I bought my Esprit 2nd hand so not exactly cheap and did go to the guys house and take a good look, but I had no idea what to check. I seemed to have been lucky and after 3 years without any optical issues I had it recently fully serviced at RVO including a Zygo test and all came back good except needed a good clean of outer lens.
But even if you do this then a week or so later there is no guarantee the seller will return the money if there are any issues found and a repair could end up making it no cheaper than new.

I guess at least buying new gives you a lot more peace of mind regarding repair or refunds.

Steve

That's interesting to know, what do they do re-adjust collimation if it needs it?  How much did they charge?

[Adam J]

38 minutes ago, newbie alert said:

That's interesting to know, what do they do re-adjust collimation if it needs it?  How much did they charge?

I would save your cash and adjust collimation yourself. Just purchase the cheap artificial star from FLO and make sure you are getting concentric diffraction rings either side of focus in the centre of the image. If not then tweak the main collimation screws (not to be confused with the centring screws!) until they are concentric. 

[teoria_del_big_bang]

1 hour ago, newbie alert said:

That's interesting to know, what do they do re-adjust collimation if it needs it?  How much did they charge?

I think so, as it happened mine did not need it but was in a good need of a clean that was just about all.
I think I paid £120 for the service but most of that was the Zygo test to check the optics themselves mainly for my peace of mind, apart from the cleaning, which I guess I could have done myself, nothing really was required to be done.

Steve

[AstroGS]

The most frustrating was the fact, that it would have been super easy for the seller to just coordinate/facilitate the repair. 
 

Also, my experience from other forums has shown me that if you are about to buy 2nd hand items, of a certain value and above, it is best to buy them from a dedicated to that subject forum. Usually, the members of those forums will be less inclined to hide issues with the item they sell, as they value their hard earned reputation as more important. 
 

Selling platforms are very often misused by people that just want to get rid of their faulty garbage, without being able to regulate that. 

Edited May 10, 2022 by George Sinanis

[AstroGS]

@powerlord well done mate. I would love to see the scope to work as it should. 

[ollypenrice]

On 02/05/2022 at 14:33, George Sinanis said:

 

1. WO are using very cheap plasticky-feel screws that can be very easily broken! Why WO?

 

Because the primary goal of any William Optics telescope is to look pretty on the outside and cost as little as possible?

Regarding the seller, I wonder if a solicitor's letter would help to focus his mind?

Olly

[Stu]

21 hours ago, Adam J said:

This is exactly why I really disagreed with the change in policy allowing people to sell items on this forum without gaining reputation first. But I suppose that I can and do look at post count when I buy from someone on here. 

Adam 

That policy has been reinstated now….

[ollypenrice]

On 09/05/2022 at 12:39, Adam J said:

I don't know Steve its happened to me a couple of times, someone on ABS literally sold me a filter wheel with a obviously stripped thread on it and I have received a scratched filter, again ABS. 

In both those cases the sellers refunded. But recently I came to the conclusion that I wont ever buy an expensive item like a mount, scope, or camera without seeing it working first. My biggest one i fear is buying optics and they are hit and miss new let alone second hand, the scope itself can look great and be utter trash, there is just no way to test it at a motorway service station meetup on the M1. 

Adam 

I once bought a refractor at a service station on the M1! I took along the bits needed to set up the classic 'illuminated ballbearing' artifical star test. The test was good so I bought the scope. It was fine - though it wasn't a premium instrument at a premium price.

Olly

[AstroGS]

New RedCat51 v2 delivered  

 

I do hope my experience this time is much better than the previous one. At least it is a brand new one. 
 

Getting it ready when skies decide to clear!

 

 

[Ratlet]

30 minutes ago, George Sinanis said:

New RedCat51 v2 delivered  

 

I do hope my experience this time is much better than the previous one. At least it is a brand new one. 
 

Getting it ready when skies decide to clear!

 

 

Absolutely delighted for you getting one that will work.  Love the glamour shots of it.

[AstroGS]

So tried tonight to get first light but, the clouds kicked in the moment they saw the red new kit shining.

But, managed to get 1 frame 300 secs from each Beehive Cluster, Soul Nebula and SH2-157. 
 

I had that need to know that is a “good” one

 

p.a. Ignore the red layer. I was going for the crescent nebula and I used the L-extreme

Edited May 28, 2022 by George Sinanis

[Adam J]

On 28/05/2022 at 23:36, George Sinanis said:

So tried tonight to get first light but, the clouds kicked in the moment they saw the red new kit shining.

But, managed to get 1 frame 300 secs from each Beehive Cluster, Soul Nebula and SH2-157. 
 

I had that need to know that is a “good” one

 

p.a. Ignore the red layer. I was going for the crescent nebula and I used the L-extreme

Looks good to me. 

Adam

[AstroNebulee]

Looks great there George 👍, pleased you have a good one now 😊

[AstroGS]

Proper first light - i can say i am happy!

 

[symmetal]

Can't complain about your new Redcat George.  Good stars in all four corners too. Better than mine which has slight coma in one corner. Bet you're relieved. 😊

I like the 3 way dovetail splitter. 😀

Alan