oymd

1 hour ago, paul mc c said:

Could be pinched optics...is it a reflector your using.

Its a WO71 refractor. The five element one which has a built in flattener.

Ambient temps are about 15C where the scope is setup. I doubt its pinched optics? Unless pinched optics can occur even when its relatively warm?

I have not touched the scope in ages, and stars were always perfect, until about 2 weeks ago.

I also checked with CCD Inspector, and there is 1% tilt only, and a pretty flat field.

Morning everyone.

Have been getting perfectly round stars for sometime, but recently I have noticed that my stars started looking a bit strange?

Any thoughts what might be causing this?

It does not look like pinched optics, and I'm certainly not imaging from a cold site?

Many thanks

Ossi

10 hours ago, Frogliza said:

Hey oymd, this is an old thread but I wanted to ask if you get good stars to the edges of your FOV? I'm using a ZWO ASI294mc and NexStar 6SE and having a similar problem to your original post.

Did 105mm of backfocus work? 

Hi

105 worked, but overall results were not great. Edges are not good, but was told that’s the best regular non edge SCTs can offer. 
I abandoned the endeavour all together and got back to my refractors. 

Here is what it sounds like. 
 

Noise got louder after tensioning the DEC belt, but it always sounded like that, just lower volume. 
 

https://youtube.com/shorts/-mzB7F8gJv0?feature=share

1 hour ago, scotty38 said:

I cannot answer your question but if you adjusted the DEC belt and it's now making a horrible noise wouldn't you be better off readjusting that first?

I did. I slackened the belt and it sounded better. 
 

My summary above is a gross underrepresentation of my issues with my DEC.

The DEC always sounded bad, but I was worried about doing any physical damage and was afraid to open up the mount.
 

My main mount is my AZ-EQ6Pro, and the CEM40 was meant as a backup for a mobile setup.
 

it’s only last week that I decided enough is enough, and I need to find out what is wrong with the mount mechanics, and decided to open it up.  

Hello everyone

Can someone please advise how to remove the saddle off the CEM40? Mine is the first iteration, the basic CEM40.

I have been experiencing very erratic guiding recently, so I tensioned the belts on both RA and DEC. Also fine tuned the DEC backlash.

The RA slewing sounds smooth and excellent, but the DEC sounds horrible, as if something is grinding inside!

Opening the RA assembly is fairly easy, but for the life of me I could not remove the saddle to open and inspect the DEC gear assembly?

I removed the small plate protecting the wires, and the FOUR large central bolts holding the saddle, but it would not budge. Its as if the 4 bolts served no purpose?

What am I missing?

Many thanks

I’d appreciate some advice regarding which OAG to buy for my setup, and pros and cons of each?

Imaging will be an Edge HD 11 + 0.7 reducer. 

Camera is the 2600MM Pro + 7x2” EFW. 

Guide camera will be the 290MM Mini, but I’m planning on buying the 174MM Mini. 

Both OAGs have 12mm prisms, and I believe both have bigger openings in their stems, so allow much more light through. 

The Celestron is considerably wider and heavier, and will take up much more space in the imaging train. 

I think the ZWO OAG has a better attachment mechanism to the EFW, where it screws on directly. I do not think the Celestron one can be screwed to the EFW. 

Which OAG do you suggest to buy?

Many thabks

Ossi

2 minutes ago, Dr_Ju_ju said:

If there is that gap around the heater, such that the heater only connects to the camera body, as you say, by your T2 ring, all should be ok, but my camera (1600) screws directly to the filter wheel body, so anything, even a hair etc, has the potential for a lopsided fit. 

ahh...I see what you mean now.

My camera is an OSC, so no filter wheel.

Thanks for the tip

12 hours ago, Dr_Ju_ju said:

you could try scraping off the insulation across the break & then selotape a small piece of baking tinfoil across the break, & if you're luck it may not introduce any tilt, especially if you 'balance' out the with additional tape spaced around the heater....

Thanks Julian

Tinfoil! That's a good idea. I will try that.

Why do you think that will introduce tilt?

The dew heater is on the camera body, and the imaging train connects to the 11mm T2 ring, which stands proud from the surface of the camera by 11mm?

On 26/10/2022 at 20:51, Tomatobro said:

If its open circuit then peel if off and fit a new one. £22 plus postage from Flo

12 hours ago, Dr_Ju_ju said:

Yes, it probably is fixable (scrape off the insulation and lightly solder a fine wire across the break) but that would produce a bump, and so introduce a till, so as suggested, it would be easier/better to just buy a new one.

5 hours ago, Tomatobro said:

When the new one is fitted put a plastic tie wrap round the camera body where the black connector comes out to take the strain off the heater connection

Thank you all for your replies. 
 

There is indeed a black zip tie on the camera body. You can see it if you look carefully at the picture. 
 

The issue is I’m on vacation and this setup is abroad at my remote Obs. 
 

FLO does not ship to where I am now. 
 

Is there a DIY fix I can do as a temporary fix till I get back to Blighty and order a new one?

I think overall the engineering and design of this ring is terrible. The power cables are very very stiff, and they are of equal length, where they should have designed them with one shorter than the other. 
 

With regards to removing the plastic insulation and soldering the golden traces, I might try that at a local electronics shop. It will not introduce any tilt as it’s no where near the imaging train. 

Evening everyone

As I was cable managing yesterday night, I nudged the power for the dew heater strip on my 294MC Pro, and I heard a snap. 
 

Looks like there’s a crack now in the wire. If I carefully tape this, would it still work?

More importantly, if I do try to see if it works, could I cause some sort of short and fry the camera, since they now share a common power port?

Thanks

I’ve just had a look at my EFW package. 
 

I'm missing the 6 silver M2.5 screws needed to fix the EFW to the camera. 
 

Can I buy those separately?

1 hour ago, scotty38 said:

I believe the 2600s can bolt to these filter wheels

That’s what is suspected, but was hoping for some advice regarding this?

how’s it done?

Good evening everyone

I've recently purchased 2600MM and a 7x2 ZWO filter wheel.

I'm staking my first steps in Mono imaging. Will be using this setup with an Esprit 100.

Can someone please advise on what is the best way to connect the camera to the EFW?

My experience so far has been with OSC, using the 294MC Pro, and never used an EFW before.

I bought the EFW used, so might be missing some adaptors, but the camera was new, so all bits and bobs should be there.

I can see that the EFW has holes on it? Does the camera attach to the EFW using adaptors, or using the screw holes?

Some pics of your actual setup would be very helpful?

Many thanks

Ossi

When considering alternatives to the ZWO 2600MM or QHY268Mono, which one is the better choice for mono imaging and why?

My understanding of mono imaging is that I will need RGB filters and a Luminance filter. 
 

Since the alternatives like the Altair 26M and Rising Cam options come with an UV/IR block window, how does that work with the RGB and particularly with the Luminance filter?

My understanding is that the ZWO and QHY options come with an AR window and no UV/IR block option?

Thanks

3 minutes ago, Pitch Black Skies said:

I know someone who is selling the 2" LRGB Baader ones. He is selling a 2" filter wheel too.

Is it the ZWO filter wheel?

I see. Silly me. Yes. They are 2mm. 
 

Guess I will go with the Antlia V LRGB. 

The Baader ones are a bit cheaper, but not in stock at FLO or anywhere else. 

The box says m48x0.75mm??

Is it possible that they are just 0.75mm thick?

I have been imaging OSC for the past 2 years, and I am putting together a Mono setup, as I think it will suit better my LP skies.

I have done a lot of reading, and plan to buy the 2600MM Pro.

I have just bought a set of very expensive 2" 3nm Antlia Pro SHO filters.

I have yet to buy an LRGB set.

From my reading, the SHO filter choice is critical, especially OIII, as there are issues with halos etc, bar Chroma and Astrodons.

With regards to LRGB, is it equally important to buy the best I can afford, or is LRGB forgiving, as opposed to SHO?

I am thinking of going with a ZWO 2" LRGB set, which is the cheapest, if it does not really matter that much?

Many thanks.

1 hour ago, DaveS said:

I would mount a rotator between the camera and the OAG, either the TS 48 mm or TS 42 mm depending on the thread size.

Ahhh....

That's a nice trick!

I have a T42 rotator lying somewhere! Its a TS optics one!

23 hours ago, newbie alert said:

I keep the long edge of the imaging camera and the guide cam and the prism long edge the same

So my imaging cam is set to 90 degrees( in my plate solve software it says 270)  the long edge of the 290 set to match the long edge of the prism...  

As in the top image and not the bottom

22 hours ago, alacant said:

Then I must have misunderstood. My flat-frame method is used to align the prism with the long axis of the sensor. English is very much my second language. Sorry!

Thank you gents for your replies

Let me clarify what my problem is:

My image train consists of Camera ===> T2 spacers ===> OAG ===> T2 spacers ===> Celestron 0.63x reducer ===> Celestron C8

As you can see, on BOTH sides of the OAG there are T2 spacers.

When I am assembling the imaging train, these spacers are SCREWED together, so the FINAL orientation of the OAG prism to the Camera Sensor is RANDOM, and it is a matter of LUCK where the final position of the OAG prism ends in relation to the Sensor.

Since the imaging train all relies on SCREWING adaptors together, I can never get the OAG prim to end up where I want it to be, in relation to the sensor?

The OAG has some adjustment, using those 3 thumbscrews, but the adjustment radium is not enough to rotate the prism enough to lie PARALLEL to the long axis of the sensor.

I have undone and redone the train countless times, and it always comes back to the same orientation.

9 hours ago, alacant said:

Hi

Mark the long edge of the sensor orientation along the back of the camera; using the writing can be misleading. Set the prism roughly parallel and take a flat frame. Push the prism stalk inwards a mm or so at a time taking flat frames as you go. Stop when you see the shadow of the prism. It's now easy to rotate the stalk to make the shadow parallel to the edge of the frame. 

Finally move the prism away from the edge until the shadow just disappears without introducing further rotation. Get it somewhere close, but don't stress over it as you may need to rotate it again to find guide stars.

HTH

I think you misunderstood me.

My issue is not the prism showing up in my images.

My issue is getting the prism aligned with the long axis of the sensor.

Using thin spacers was mentioned above, but that will alter the backfocus.

Since this is my first experience with an OAG, I would appreciate some advice regarding setting the prism location PARALLEL to the long axis of the CMOS sensor?

I must be missing a trick?

Since I have quite a few T2 extensions between the OAG and the camera, the position of the prism is dictated by the turns of those extensions when I am screwing them all together. I then have a few degrees of rotation adjustment on the OAG by those three adjustment thumbscrews, but I seem to NEVER get lucky and get the prism to end up on top part of the long axis of the sensor?

No matter how many times I unscrew everything then screw them back together, I never managed to get the prism where I want? Is there a trick I am missing?

On 12/05/2022 at 08:40, newbie alert said:

I love my non edge XLT 8 for imaging..I'm enjoying it so much that it's not been off the mount for over a year

A heavy dither will sort out you colour mottle on the background sky

2nd image shows a flare off the star, could be that the tube wasn't cooled to ambient temperature, or collimation.. have a scroll around and if the brighter stars all have flares then certainly could be collimation, is this a full image or a crop? 

Also I don't get your guiding, the RMS figures look really good but doesn't correspond with the star profile target and  peak to peak rms

 

 

I am dithering every frame, but I guess I need to increase my dithering value.

Yes, guiding is always between 0.5 to 0.7, which would get me FANTASTIC stars on my refractor setup, but for some reason here, it does not match the result I see on my images.

1 hour ago, Cosmic Geoff said:

I have tried unguided imaging with a C8, and ASI224 MC camera. At f10 most images were so soft and small-scale as to be almost unusable.  Results at f6.3 were much better. I think the seeing affects the softness of the images achieved.

agreed, its just an experiment i thought id give it a go!