StarlightHunter

The filter is so near the camera if you thread the adapter in the 11mm ring (the one closest to the camera) that I think it should not be vignetting, or at least it should be something very light.

22 hours ago, AstroNebulee said:

Thank you for the advice on a ir/uv filter, would it be a 2 inch one? Or could I fit a 1.25inch one direct to the 294mc pro? Yes I hope to achieve focus, I think I will have to get the focus tube in a little bit more than without the rotator in. I'll let you know 👍

If you have the 2" one you can fit in directly in the rotator. It you have a 1.25" filter the best option is to use the adapter that came with the camera to put it inside the 11mm ring.

I'm sure it will workI was usin the same rotator/lattener/spacers/camera and you will achieve focus.

Just a suggestion: use an IR/UV cut filter. you can thread it inside the rotator. That way you will not get very bloated stars.

I edited the comment as the image was not being shown.

Here you can see my setup.

In the top-down order:

72ED without the 2" eyepiece adapter

treaded to:

Field rotator from FLO

threaded to

OVL flattener

threaded to:

ASI 294MC-Pro camera and spacers (using the OAG).

The spacers I used with the camera are the ones in this image

And I achieve focus without any problem.

Hi @fozzybear

I've just rotated it counterclockwise like any other thread.

If it is rock solid in your case maybe you will need to use some tricks.

Apply some heat near the thread with a lighter and then, with a thick cloth in your hand try to unscrew it. You could also use WD-40 but that could spill over the lens and maybe damage the coating.

No other ideas for that.

I'm using this rotator with a OVL field flattener in the old version of the 72ED with an ASI294MC and it works perfectly.

At least for me, I get focus without any problem. I attach the rotator, then the OVL flattener then spacers to get 55mm backfocus and then the ASI294MC-P.

All works like a charm.

Ok. The best option here is to check on field

I will need to find some time and clear skies to do some testing.

Thanks!

27 minutes ago, ebdons said:

Hi depending on the optics of the scope I use cls (non ccd) with ir cut only on frac optics achro apo sct etc, when use on my newt then no need for the ir cut I found and yes you're correct about star bloat but I use the IDAS NB1 and NGS1 on my apo and achro and they both limit star bloat albeit the NB1 is better, I don't know if this is what you're asking? ton

Yes, That's exactly what I was asking. Thanks. I've an SW ED72 APO so I should need IR correction on a non filtered camera.

Newts and non refracting telescopes do not need IR filters AFAIK.

I was more concerned about reflections, focus problems or even less light coming to the sensor because of two filters being stacked.

Just to add more information to this flattener thread, it has a 2" thread on the telescope side so you can screw filters on it.

Ok. To finish this thread and to solve the problem I had, the real problem in my case was the ED72 not being well aligned.

The focuser body was misaligned with the rest of the telescope because of a failure in the body attachment building. I just got a colimation eyepiece like the one of the photos and I was able to align the body and retight the screws so now it is well aligned.

Hi there.

I recently adquired a ASI294MC-Pro camera and I read OSC cameras works better using IR/UV filters to avoid star bloating.

I adquired two filters from Aliexpress, both of brand Svbony. One is the UV/IR and the other one is the CLS filter as I live in a very poluted area.

The thing is the CLS is not a CLS-CCD filter, so it does not block IR, so I wanted to know if it is "wise" to pile up both filters so I can block IR/UV and city lights.

Had anyone tried this before?

I attach some photos of the CLS filter and a test I did with my DIY spectrographer

21 hours ago, Deeko said:

Just we I am on the same page here - when you unscrew the bevel on the OVL as in your bottom photo, it reveals an M56 female thread? Second question - how did you unscrew the bevel, mine is rock solid!

Yes. M56 female that fits directly into the rotator.

About being rock solid, I just unscrewed it. Had not any problem doing it in my case. I think you will need to try tips and tricks for blocked nuts and screws.

Just for your interest. I recently bought an ASI294MC-P and using the spacers the flattener and the rotator all works perfectly and can achieve focus in the middle of the focuser length.

On 26/07/2019 at 13:50, NAugustin said:

Nope, it´s not fitting. Also, I got the Info from OVL that the Rotator is threaded M56(M) for the SW Reducer/Flattener while the OVL Flattener is M48 thread.

Therefore, I bought an adapter M56(F) to M48(M) together with my Rotator BUT its not fitting the Rotator. Somehow this is again some weird angle of the thread that after a few turns the adapter can not be screwed fully onto the Rotator. Don´t know if I can use it like that (see picture) but at least I have to test if I still get into focus... I like the OVL flattener and did not plan to get the 0.8 reducer/flattener from SW...

I received my rotator almost a month ago and it fitted perfectly with the OVL flattener. You need to unscrew the beveled part of the flattener. That's it.

Here it is a photo of the fitting. Hope this helps

Thanks for the info. I will order it then.

Any news on connecting this accesory to the OVL field flattener?

I'm interested too.

Yes, I was about to buy this one:

But I'm pending of FLO answer about compatibility with the FLO flattener

In the images the distortion changes the position and they are taken with different camera rotations.

Thanks. I supposed the problem would be most probably due the attachment. I will order a threaded attachment because I'm using the most basic 2 thread rings that comes with the scope focuser.

Hi there.

I am using an OVL field flattener with the Skywatcher 72ED and I am getting some weird distortions.

In the image https://starlighthunter.com/imagenes/galaxia-de-andromeda-m31/  the distortion is very evident at the bottom side.

In the images https://starlighthunter.com/imagenes/nebulosas-trifida-y-de-la-laguna/ and https://starlighthunter.com/imagenes/cumulo-globular-m4/ it is at the bottom-right  side and barely noticeable.

Today, watching some images at astrobin I found this one:

https://www.astrobin.com/full/379566/0/

Same configuration, same problem (this time left side). Any clues about this?