Neko

Hi, 

did you try changing the motor value (ranges from 1 to 3 ) in the settings ? 

Regards, 

Carles. 

Hi Steve, 

thank you, I have seen that review, but he is using a small guide scope though..  

couldn't find any other (well found one in japanese a while back but was similar) 

Thanks for your help

Regards

Carles.

Hi all, 

I have recently bought an OAG to use with my SCT 8" with 6.3 reducer, and the only guide camera I've got, that usually use with

Evoguide50ED, is an old (first gen) QHY5m camera...  Having tried that on the mentioned setup with the OAG, found it hard to get

stars, and also hard to focus, So I was looking into an affordable alternative and saw that sv905c (to also use as planetary, occasionally) 

So I was wondering if any of you got experience with this camera, specially for guiding. Haven't been able to find many reviews (actually

just 2) or opinions. 

I am aware (or maybe just a wrong guess) that any present/modern camera will be more senstivie and thus being able to get more stars

than my old QHY5, but just wondering for affordable alternatives. Interested on the "mini" format as then I could use the mini helical 

focuser that comes with the Askar OAG, as with the QHY5 I have to remove it and it makes things harder too. 

thanks in advance! 

Carles. 

2 hours ago, skybadger said:

The point is really to rough adjust using the black known and then fine adjust using the screws. No slip that way. I sold my sp after putting LX belt drive on it. . Still have a Dx with ss2k. 

 Not that it slips.. but sometimes when changing direction it might move; itbhappen to me that PHD2 reporting. polar alignment value and a different one when changing direction or area of sky. Hence why..

What's the LX belt ? I have ss2kPC on my SP, but was thinking on modding with belt.  As a Japanese friend who has done it with GP told me, it is hard to get proper tension, as it doesn't have a good way to do it in that mount. 

Would like to know your experience with belts in an SP

1 hour ago, skybadger said:

The knob is an indexing clamp for course latitude adjustment.  underneath there is an indexed plate, release the knob, move the mount by an index (think gear teeth or splines) and retighten, then fine adjust for latitude using the screws. It came like that from the manufacturer. Some people removed them as they were a bit 'fussy' sometimes to setup. 

Yes, I've taken down the whole mount few times.  That indexed plate limits to some degrees the amount of latitude to be sdjusted. If doesn't reach, needs to loosen the main screw, move the outer plate that keeps presure with an Spring, then tight again. 

Still , if you had adjusted your polar alignment with polar scope, and when youre ready , tighten that black knob , you'll see polaris position shifting.. even if you just stand at the back of the mount and tight that knob, you'll see a tilt.   Since I discovered that, i leave it loose, and insted installed that screw in front. 🤷🏻‍♂️ 

Guess because that issue, later models (including vixen SP-DX, GP, GP-DX...and clones ) have already an screw fixing in front lile this one;

Sure, you can turn it around, but look at the worm in case is not damaged. Sometimes bending was the result of over tightening de mesh... When i got mine (second had too, many years ago ) it was also bent. So I've replaced it. You can try that "fix" or just  get a replacement.  All depends if it will be for visual only or AP

Recently one of mines had the worm a bit bumped.. looking closer.

https://teleskop-austria.com/WormEQ3#m

You could measure yoirs and check with the shop,  but considering that eq3, eq5 snd others are  copies of vixen polaris /super polaris/great polaris, i think it could be compatible 

21 hours ago, Pixies said:

Yey! The polar scope illuminator still works!

The old battery was still in there. Lots of blue fuzzy corrosion to remove (and my fingers are still a bit 'stingy')

A quick question about the mount, and I can't see anything in the manual. What is this knob for?:

That black knob is for fixing the latitude. But I've found it very ineffective, and to me it also producing some tilt to the axis in the mount. 

It would be the old version of the nowadays screw on front that stops the whole mount to move  in latitude. 

In that post you mentioned ive fone a mod for it. Is not great, but linda works better than this 

The tripod is lile mine, but yours is taller : ) 

about the bent part, I think you could get a compatible eq3 or eq5 psrt for it. 

also you've got the unofficial manual in German, English and Spanish (this last one, translated by myself 😛 ) 

it is a very complete, well structured manual, very helpful. 

you can download it from "download" section, or the Eng version straight from here

https://www.startools.org/downloads/unofficial-english-manual-

^^ 

Carles. 

On 14/01/2021 at 02:23, Eryk Mozejko said:

Looking at the photo il guess the material is either a PE or PTFE. drop it in water , if it sinks its PTFE, floats is a PE.

probably the best thing would be get a 0.5mm sheet of PTFE and cut 3 or 4 bearings so you can try them stacked like a shim to get the right results. 

I would think !.5 mm would be the right thickness as the part number listed is the same. The end ring on the shaft should dictate how much gap is taken up to get both bearings to mate with each surface.

At least with shimming layers of 0.5mm sheet you can experiment with which gets you the best results. otherwise by a small ball of a putty like substance. Something like Blu-Tak or what ever equivalent is available locally to you (its a product used to stick things like posters on walls temporaily. usually obtained from office stationary suppliers. stick the ball up against where the bearing should go. then fit the shaft in place without turning it. then pull it apart. hopefully the putty with have bee squashed into the thickness of the smallest gap between the two surfaces the bearing is to fit between.

 

Hi Eryk, 

sorry for the delayed reply. I finally gotten PTFE washers from UK , but weather here in spain has been awfull so couldn't test much till recently . 

I have ordered 1mm 0.5mm and 0.25mm . and played with it a bit, but indeed in Dec with the addition of the washer, tracking kind of improved a bit, but specially dithering has had a massive improvement. 

Attached are PHD2 logs from a session from last month. Same night,  just different parts of the sky (South-East and North-Zenith)  dithering movement and recovery was pretty fast (before it took around 2minutes or more.. ) backlash seemed to improve too  I don't know exactly why Polar Alignment value changed throught the night..perhaps flexure of some kind , no idea. 

Quote

I like the idea of the return screw you have to stop the RA body from slipping in its altitude adjustment. by taking off the plate 1-9 there should be two small grub screws, silver in colour now visible in the 4 and 8 o'clock positions. tightening these applied pressure in order to help stop the whole mount from tilting on its altitude axis on its own. But these two screws also stopped that side of the part 1-2 from clamping part 1-3 properly from both sides. Which denied the mount its full capacity to carry heavier equipment.

That is something too...the screw I've added somehow helps, but not a lot. I was thinking if there would be a way of changing the whole latitude adjustment base . The silver colour screws you've mention, I have adjusted a bit but as you say, too much will refrain the mount from moving..and I have to Polar Align often since the mount is outside, but the telescope I mount it each time and it might move. 

Eitherway, the washers did it's job. Indeed it was weird that it was missing in both axis... in DEC I think I've ended up with 0.50mm. And also added one to RA.  Still a bit more to tune up but so far, so good

I own and currently using the QHY8L  with optolong L-pro filter. 

And I am pretty happy with it. Bought it used also, but I paid a lot less since when I got it it wasn't working, then sent it myself to qhy and they fixed it

no problems since.  As comments avobe mentioned, depends on your focal lenght... but I mainly use it with my Borg 89ED focal lenght 600mm, a bit undersampled, but doesn't look bad either. 

One thing that  I don't like much is the TEC regulator, DC201, which is separate from the main camera, which adds another cable and so on. 

Carles. 

I own a Borg 89ED and quite happy with it..now that I've changed the focuser. 

I'm using it for visual grab and go and also for imaging, and I think optically is good.

The one you mention is fluorite, so probably will be better. 

I really like the way it can be taken appart in few pieces for better transport.

BUT ,  the draw tube kind of system, even though it makes it easierto make it compact

and portable, is horrible.. and not very reliable.  I think the 72FL doesn't have this,

and probably goes with a good rack and pinion or crayford focuser.  

Also is very light weight! 

On 02/05/2021 at 23:11, happy-kat said:

There's more back focus available with the starizona evoguide field flattener I think.

Yes, but the cost is about twice as the sw one, and also there's no availability so far for starizona one.. 

Last try for now 

Similar as before, but with a more conservative process (less HDR in the core..) and different color

StarTools and LightRoom. one with aggressive noise reduction and one without 

hope you like!  Really impressive data to work with!

Second try  

This time StarTools 1.7 only. 

Similar workflow but less aggressive and cropped a bit. colors came out better too

So didn't think the need of exporting to lightroom this time 

As always, thank you for such awesome data!! 

here goes my first try

StarTools 7 and Lightroom 

Last try! .... unless I can come up with something very different! haha 

Again thank you for let us play with this wonderfull set of files hope some day I can capture something this awesome myself! 

This was with new H-a v2 file, RGB legacy  in Compose module in StarTools v1.7 . Not layering, just straight blending of red + h-a. then

compose as usual. 

I still think there is some faint nebulosity around so tried to pull it out and like it this way : ) 

Second Try!  Almost same process as before

StarTools 1.7 and Lightroom. 

This one is as challenging as fun!!!  

This is my first go, perhaps went too far with sharpening, but will try once again! 

I thought it was a gradient too, but then I've realised this is around 100hour integration time..and it could be nebulosity? So I've processed it this way. 

StarTools 1.7, Compose module. Merged Halpha + Red channel, and wiped cropped all files before loading them in the module, then sort of normal workflow

finished in LightRoom. 

21 hours ago, Dougie Smart said:

Hi All, just to let you aknow that the  polar scope for the Skywatcher EQ5 fits my Vixen GP DX EQ mount perfectly 👌.

Thanks again for your help guys. 

Glad to hear that!   enjoy! 

I think it will work fine. As far as I know the htread is the same for the vixen mounts, as the EQ3 , 5 and are clones of the vixens. 

Hope all goes well ^^ 

Carles.  

6 hours ago, Dougie Smart said:

Thanks for your reply and advice Neko.

In order to remove the Vixen polar scope, would I be correct that the grub screws need to be loosened first, then the polar scope unscrewed?

I am waiting for an Allan key (wrench key) to be delivered so that I can remove the scope from my mount.

I hope you can further advise.

Thanks agian,

Dougie

ummm, maybe I missunderstood. You want to change only the reticle? 

I've changed the whole thing for one of this 

hhttps://www.alphacygni.com/buscador-de-la-polar-y-accesorios/1506-buscador-de-la-polar-sky-watcher-eq-5-eq-6.html

What I did was just unscrew the whole thing out, and put this one. You don't need allen key for this. Just grab it firmly with your hand and unscrew it. or at least I didnt need to unscrew anything, And I took the mount a part few times...

That's all. I had to collimate mine. So probably you'll have to do it too. 

22 minutes ago, Froeng said:

Hi Dougie,

i have used the below in my 30+ years old SP-DX and it works perfectly.

https://astrogarten-shop.de/en/accessories/mounts-tripods/optional-parts-accessories/vixen-polar-axis-plate-year-2005-2025.html?language=en
 

Frank

That's way to expensive... 

https://teleskop-austria.at/polarHMRet#m   this would work and is more intuitive 

@Dougie Smart if you wan to change only the glass reticle, then this one would do. If all the rest is OK

32 minutes ago, Tomatobro said:

Have a look at https://optcorp.com/blogs/astronomy/how-to-set-the-correct-back-focus

I'm aware of this. I followed the instructions for the Hotech ff on my Borg. Just wondered the effect. In the site they show those graphs, and according to it would distort all the field ?  

Guess a good way to test it would be modifying the distance in my Hotech+borg combination to see the effect.   But weather is bad enough for long to waste next clear night on this 🤣🤣 

Thanks for your answer anyway

I replaced my Vixen's Super Polaris polar scope with one of those, and it works great. 

the thread is similar, although in my case it doesn't screw all the way in. 

I did order EQ5/6 version, maybe for my mount EQ3 would fit better, but it works

So it should work for your GP too 

Regards 

Hi folks, 

I wonder what happens if one can not reach the ideal back focus distance with a field flattener? 

For instance, my QHY8L has 20.1mm back focus, but the Evoguide 50ED FF requires 17.5mm  

then, how the images would look like? those 3mm of the sensor being too close to the FF would it 

make it not possible to focus? or will focus but wouldn't correct the whole field?  

Withouth the FF  I can reach focus but maybe about 50% of the frame (or more? ) is distorted, obviously

So, what's the theory behind it? Not reaching the ideal backfocus makes the whole field distorted or

just can not correct a certain % ? 

Sorry if that is a too dumb question ^^;