New ZWO mono camera on the way?

[DaveS]

Interesting QE curve, peaking in the [OIII] - H-Beta region. Is that a function of the IMX 571 sensor itself?

[Spongey]

4 minutes ago, DaveS said:

Interesting QE curve, peaking in the [OIII] - H-Beta region. Is that a function of the IMX 571 sensor itself?

There has been some discussion on this over on CN.

TL;DR: There is some doubt cast over the published ZWO curve, and the QHY curve seems to be more believable (subjective, of course) 

[DaveS]

Thanks for the link, and yes I did read it all.

[gorann]

Just read that CN thread and there is a lot of uncertainty about the correctness of the QE curves. And when comparing the performance of this camera (ASI or QHY) to the closest predecessor, the ASI1600MM, it wins an all accounts, including chip size, dynamic range (16 bit), more well depth, no amp glow, no micro lensing, and certainly more QE.

[Deeko]

Has anyone taken delivery yet of the 268M? Close to buying but unsure of how it would actually connect to my ZWO EFW 7x 36mm filter wheel. Same question on CN but nobody seems to be able to confirm the connection on the 268M as photos of it on retailers site actually show the 258C which folks say has a different connector. Quite confusing.

[gorann]

22 minutes ago, Deeko said:

Has anyone taken delivery yet of the 268M? Close to buying but unsure of how it would actually connect to my ZWO EFW 7x 36mm filter wheel. Same question on CN but nobody seems to be able to confirm the connection on the 268M as photos of it on retailers site actually show the 258C which folks say has a different connector. Quite confusing.

I am also very tempted and a bit confused. The tilt plate (as seen on the QHY site) looks different between the M and C models - does anyone know why and what consequence it may have for adjusting tilt. I worry that it cannot be adjusted without removing the camera, especally on a RASA.

[Spongey]

5 minutes ago, gorann said:

I am also very tempted and a bit confused. The tilt plate (as seen on the QHY site) looks different between the M and C models - does anyone know why and what consequence it may have for adjusting tilt. I worry that it cannot be adjusted without removing the camera, especally on a RASA.

Neither of these are actually 'tilt' plates, but it is stated as such due to a poor Chinese translation. The interface on the 268C is a dovetail type adapter that allows for camera rotation. 

The interface on the 268M is only the bolt on configuration. QHY provide an adapter in the box that converts this bolt on interface to M48, and consumes 5mm backfocus (see my above post regarding adapters included with the 268M). Otherwise, it is possible to bolt the camera directly onto the QHY filter wheel / their other bolt on accessories such as OAG etc.

[Deeko]

1 hour ago, Spongey said:

Neither of these are actually 'tilt' plates, but it is stated as such due to a poor Chinese translation. The interface on the 268C is a dovetail type adapter that allows for camera rotation. 

The interface on the 268M is only the bolt on configuration. QHY provide an adapter in the box that converts this bolt on interface to M48, and consumes 5mm backfocus (see my above post regarding adapters included with the 268M). Otherwise, it is possible to bolt the camera directly onto the QHY filter wheel / their other bolt on accessories such as OAG etc.

Thanks for the info! For using the ZWO EFW 7x36mm it seems I will be working with a starting point of 17.5mm bf (12.5mm + 5mm adapter) . I could reasonably add another 5mm to that for total distance between the filter glass and camera sensor giving ~22.5mm.  Put these numbers into the CCD calculator (image below) and looks like the 36mm filters will be just fine, even with a few mm extra on top of the 22.5 bf. Now I just need to look at soring out the rest of the bf to connect to my flattener/reducer.

 

Edited January 24, 2021 by Deeko

[DaveS]

I will wait until my 268M turns up and I can see exactly what spacers are provided before trying to second guess what is needed. There will be plenty of time before the next clear night. Months probably.

[Xsubmariner]

 I suspect the 268M will come with the same spacer kit as the 268C, which is also identical to the 600L. While hoping to get the 268M next week, it’s unlikely I will get any imaging done as the sky here looks dismal for a week or so.

The 268C doesn’t come with a tilt plate, it has a dovetail coupling to enable the camera to be rotated. I don’t like it much as it’s possible to off-centre the camera. Once I have the camera centred I only loosen one screw to rotate or remove the camera. I am thinking of using locktight on the other 2 screws.

[Deeko]

With all the info I had I pulled the trigger for the 268M at the introductory price. I'll wait until I have a play with it until I sell my ZWO 294MM, was just getting used to it too

[SamAndrew]

Yep also pulled the tirgger now on the 268M, expecting it by the end of Februrary. I've held off on the filters and wheel for now. Planning to get the new Antlia 3nm filters once they become avaialble at 365 astronomy. Shame the ZWO version is £400 more, the usb hub is a nice feature.

[Spongey]

Just now, SamAndrew said:

Shame the ZWO version is £400 more, the usb hub is a nice feature.

I couldn't agree more. If they were more similarly priced I almost definitely would have gone with ZWO, but that extra £400 is effectively a 'free' filter wheel and more. It seems that ZWO have done a great job at building a customer base among the community and are now reaping the rewards. 

[Deeko]

1 minute ago, SamAndrew said:

Yep also pulled the tirgger now on the 268M, expecting it by the end of Februrary. I've held off on the filters and wheel for now. Planning to get the new Antlia 3nm filters once they become avaialble at 365 astronomy. Shame the ZWO version is £400 more, the usb hub is a nice feature.

I am looking at those Antlia 3nm filters too, hope to see some good reviews of them comparing to the likes of Astrodon etc. as those prices are insane and keep creeping up.

[gorann]

I just joined the club and pushed the button for the QHY268M from Modern Astronomy. Bernard promised that shipping to Sweden would be no problem, I hope he is right🥴

Edited January 25, 2021 by gorann

[gorann]

On 24/01/2021 at 10:53, Spongey said:

Neither of these are actually 'tilt' plates, but it is stated as such due to a poor Chinese translation. The interface on the 268C is a dovetail type adapter that allows for camera rotation. 

The interface on the 268M is only the bolt on configuration. QHY provide an adapter in the box that converts this bolt on interface to M48, and consumes 5mm backfocus (see my above post regarding adapters included with the 268M). Otherwise, it is possible to bolt the camera directly onto the QHY filter wheel / their other bolt on accessories such as OAG etc.

So now I have one on order 🥴 and need to find out how to attach it to my telescopes. I will use it on the RASA 8 so there I need a female T2 thread and then I want to use it with a filter wheel on my Meade 14" ACF, but I think I will stear away from the bolted wheel and rather want to screw on the filter wheel on a M48 or T2 thread so I do not need to take the wheel apart and unscrew all those small screws to get it onto my RASA. So I am thinking about a Starlight Xpress  5x2" wheel. How do you know that the camera comes with an M48 adapter? On the OPT and QHY sites it says Female M54x.75.

[Spongey]

1 hour ago, gorann said:

So now I have one on order 🥴 and need to find out how to attach it to my telescopes. I will use it on the RASA 8 so there I need a female T2 thread and then I want to use it with a filter wheel on my Meade 14" ACF, but I think I will stear away from the bolted wheel and rather want to screw on the filter wheel on a M48 or T2 thread so I do not need to take the wheel apart and unscrew all those small screws to get it onto my RASA. So I am thinking about a Starlight Xpress  5x2" wheel. How do you know that the camera comes with an M48 adapter? On the OPT and QHY sites it says Female M54x.75.

The 268M comes with the following adapters as marked in red and blue: 

These are all the bolt on type, and (I believe) are all spacers except the end piece, which provides an M48x0.75 female thread. This can of course be attached directly to the camera as it shares the bolt pattern with all the items in the diagram. M48 to M42 adapters are relatively common so shouldn't be too tricky to find.

From the images I have seen it doesn't look like the camera has any threads on it directly.

 

Edited January 25, 2021 by Spongey

[Spongey]

Duplicate post

Edited January 25, 2021 by Spongey

[gorann]

The first recipient of a QHY268M has to tell us what came with the camera!

[Deeko]

1 hour ago, gorann said:

The first recipient of a QHY268M has to tell us what came with the camera!

Will not be me! Probably second half of Feb before I lay eyes on it, but might be lucky. In the meantime I am still having great fun with the 294MM and still not used the unlocked 1x1 bin mode yet.

[DaveS]

Yeah, I can't decide on which adaptors, spacers etc until I get my hands on the actual hardware.

[tomato]

It’s a plus IMHO if the mono QHY camera comes without the 3 screw dovetail adapter. It’s not the best way of attaching a camera to an optical train, especially one as demanding as the RASA.

[DaveS]

It doesn't come with the dovetail which is a bit of a pain for me as it would make rotating the camera a doddle without having to rotate the filter wheel and upsetting the balance. ASA mounts are extraordinarily sensitive to balance.

I would like to know what camera side adaptors come with it as I would like to attach it to my ols SX filter wheel.

[gorann]

1 hour ago, tomato said:

It’s a plus IMHO if the mono QHY camera comes without the 3 screw dovetail adapter. It’s not the best way of attaching a camera to an optical train, especially one as demanding as the RASA.

Agree and depending how long they are they could even cause spikes in the image on a RASA 

[teoria_del_big_bang]

3 hours ago, DaveS said:

I would like to know what camera side adaptors come with it as I would like to attach it to my ols SX filter wheel.

What SX FW do you have and do you plan to use 2" or 36mm Filters.

I have a similar dilemma in that I am really tempted to upgrade from my ASI1600mm to either of these 2 cameras but only have 36mm filters and really cannot justify the cost of new camera FW and NB filters.
With the plate on either camera using 17.5mm of the BF if screwed onto the SX FW which is then another 15 mm (approx) to filter then 36mm filters should be okay, albeit only just.

Do 36mm unmounted filters actually have 36mm useable  diameter ?
I am assuming it will be less due to the fact they do mount to a hole smaller than 36mm on the wheel, and there maybe some alignment errors and I guess ideally the light path needs to be a reasonable clearance of the hole in the wheel to avoid reflections or other issues.
But I am guessing 32.56 mm minimum size should mean 36mm are okay to use?

However, bolting the camera to FW seems a better solution so If I go for the  QHY268M then I can buy the 7X36mm wheel that goes with it for same price as the ZWO camera, but I do like ZWO so do I wait for that one and see how it performs with my current SX wheel  and if issues then hope the promised ZWO 36mm bolt on FW makes an appearance soon ?

God why can I never make a decision 🙂 

Steve

Edited January 26, 2021 by teoria_del_big_bang