Knighter

Hi has anyone had any experience with the Zwo auto focuser and in particular using it with the ASIAIR pro. I am deliberating buying one for my skywatcher 130pds. Has anyone used one on this scope before?. 
regards

Matt 

8 hours ago, LeeHore7 said:

You should be able to use pipp software https://sites.google.com/site/astropipp/to convert the video files to tiff, ser or avi output I think and then stack in autostackket3 software https://www.autostakkert.com/

Hi Lee thanks i have used slow shutter with good results with my iPhone, but I have made the switch to ASIAIR pro with one of their ccd cameras I have all the kit apart from the mount which I ordered about 2 months ago and still waiting. I have ordered the ioptron cemp-25. I sold I’m other mount several weeks ago to help pay for it all so now waiting.....not so patiently anymore 

On 26/06/2020 at 00:39, sputniksteve said:

Hi Matt,

Which eyepieces did you use for these? Did you use the ones that come with the Skymax?

The first image is absolutely gorgeous. 

Is the blue tint on the edging of the second image - chromatic aberration? 

Hi Steve, I used a zoom lens the problem is you can see exactly what magnification you are on bu it’s around 16mm I think. The zoom is 8mm to 24mm 

20 hours ago, sputniksteve said:

That's a really nice picture. Was this with the zoom eyepiece and if so, at what level of zoom was it?

Hi yes it was I think that was around 17mm zoom. It’s difficult to tell as there are no fine markings on the zoom piece to determine the exact mark but roughly 17mm 

22 hours ago, Victor Boesen said:

The FOV of the camera and scope at prime focus should be small enough so you don't need an eyepiece or barlow. Also, I don't even know if you can reach focus through an eyepiece with a ZWO camera?

Short answer: Yes:)

Perfect thank you for the advice 

22 minutes ago, Paul M said:

I too will have a bash at guiding my 127 Mak with the ASI120mm and the 50mm spotter. I suspect it will be ok using my DSLR as the imaging camera but less successful with the ASI178 due to it's smaller sensor.

Eyepiece for visual observations? Yeah, sure. Great on the moon and planets. You need good eyepieces to get the best views though.

Eyepiece projection for astrophotography? Whole different ball game. Tried it back in the day with a film camera with poor results. You can end up with a huge, dim image that is impossible to image with an astro camera but can put a phone camera to a low power eyepiece and get great images of the Moon. But eyepiece projection a regular imaging arrangement isn't a path I'd go down! 

Barlow projection is ok on shorter focal length acopes so long as your alignment and guiding are ok but you'll struggle on a 127Mak. 

I even have a silly plan to try the 127 as a guidescope on my 250 Newt! The numbers work, just, but the mechanics aren't so good. Not least of the problems would be the combined weight and torque of the 127 swinging off the back of the Newt. Actually, it's a bad idea

Yes that’s what I thought I have a 7mm to 24mm zoom eyepiece and with the ezxyz phone mount with my iPhone got some great shots with the set up. I think if the zwo mini scope dosent work will bite the bullet and get the off axis setup and be done with it. I will let you know how I get on. 
this is as a picture if the moon with my iPhone and mount 

On 29/06/2020 at 19:46, Victor Boesen said:

Well FLO have done a good job once again;) Mount is perfect.

You can definitely use the eyepiece for visual observing since it'll allow for a wide field of view despite the telescope's focal length, but for imaging you shouldn't use it. 

Hi Victor, so am I right in thinking even for planetary photography not to use any eyepiece even for the moon?  

12 hours ago, ollypenrice said:

Quite near the top of the mountain, in fact! 😁

Let's get back to basics, first in theory: the resolution of detail involves 1) the resolution of the optics which, when they're diffraction limited, is proportional to aperture. A 127mm scope has a theoretical maximum resolution of 0.91 arcseconds. It can distinguish details 0.91 arcseconds apart. Details closer together than that connot be distinuished. There is no way round this rule.

2) The resolution in terms of the camera-and-lens as a system. The unit of interest is arcseconds per pixel. (How many arcseconds of sky land on one pixel?) If the system is working at 2 arcsecs per pixel any two points less than 2 acsecs apart land on the same pixel so will not be distinguished.

Whichever of these values is the worst in terms of resolution will define the best resolution of which the system will be capable.

Now for the practice. Photographic systems with high resolving power soon fall foul of other limiting factors which override their theoretical resolution. These include:

1) The seeing. The atmosphere distorts the incoming beam, sometimes by very large amounts. It isn't unusual to be limited to 2 arcseconds or worse. Sometimes it's also better than that. Local conditions determine the limit.

2) The guiding. Divide your imaging pixel scale by 2 for a rough idea  of the guiding precision you'll need to support that resolution. A good (not an average but a good) mass production mount can usually manage a guide error of about 0.5 arcsecs. That means that you are, in reality, limited to 1.0 arcsec per pixel for imaging. 

So even if we ignore the optical limitations of 127mm we find you are trying to image at 0.5 arcsecs per pixel. This would need incredibly good seeing (unlikely) and a guide error of 0.25 arcsecs. (Also unlikely! Our excellent Mesu 200s deliver around 0.3" at their best.)

Enter another key term, empty resolution. If you open a high quality image in Photoshop, one which was correctly taken at the limit of the system) and look at it full size on your screen you are seeing all it can give. You can hit Ctrl+ and make it bigger. Or hit CTRL+ again and make it bigger still... but it contains no new resolution. Doing this is a waste of time. The detail just isn't there. And so it is with imaging at unrealistic pixel scales like 0.5"PP. The same information will be landing on several pixels. You'd be better off with bigger pixels which would 'fill' faster. One way to do this is to bin pixels 2x2 or 3x3 where this is possible.

Olly

Hi Olly thanks you for this I clearly have a lot to learn really interesting 

3 hours ago, rob_r said:

Longer focal lengths can lead to flexure where the scopes will be pointing at different points in the sky. I have read on the link below that off axis is best for focal lengths over 1500mm to 2000mm. I have the same scope, the SW SkyMax 127 and considering getting a guide scope and camera. Through my own reading up on the subject, I came across this article, https://agenaastro.com/articles/guides/autoguiding/selecting-a-guide-scope-and-autoguiding-camera-for-astrophotography.html and lists some recommendations although it is now a couple of years old. 

Thanks for the link will take a read Thankyou 

5 hours ago, Paul M said:

I'm not sure it's viable with the small 50 spotter as it doesn't have so much focus movement and would probably have a poor image. I think the way forward with a very high guide ratio is a longer focal length guide scope, binning the imaging camera or switch to off axis guiding.

From my readings it seems the off axis guider is preferred for long focal length imaging for a number of reasons.

Some would say it's the only way to go.

Hi Paul yes I spoke to FLO today and they pretty much said the same thing, but they also said people have had success with the zwo mini scope with the 127 mak so will give it a go first and see how I get on before spending more money. This is becoming an expensive hobby!. But well worth it!!

would you also not use any eye piece looking at planets too, like the moon for example? 

23 minutes ago, Knighter said:

Hi Paul, that’s great information thank you very much, really appreciate it 

Matt 

Hi Paul so can you use a 2 x Barlow on the guide scope that would take the ratio on the calculator to below 1.10 it takes it to 1.09

10 hours ago, Paul M said:

I did a bit of looking round myself. I'll use the ASI120mm with both my 250 Newt and the 127 Mak. Lots of varying views about image scale/ratio between main scope/camera and guide scope/camera. 

I hava an ASI 178 on order too. This tool: http://astronomy.tools/calculators/guidescope_suitability Gives these options for imaging with the 127

 

The guiding ratio in the bottom green box is the important number. It's below 1:10 for my 1200D as the imaging camera but above for the ASI178.

It seems that keeping the ratio below 1:10 (well below, if possible) is key to sucessfull guiding. For my 250 Newt it gives much better figures.

Given the numbers above, without binning, I expect the ASI178 will be difficult to guide with a 120mm guide camera through a 50mm spotting scope/guide scope on the 127 Mak

Put your own figures in that tool and see what you get. The result isn't definitive but a measure of how sucessfull your guiding might be.

Hi Paul, that’s great information thank you very much, really appreciate it 

so can you use a 2 x Barlow on the guide scope that would take the ratio on the calculator to below 1.10 it takes it to 1.09

Matt 

6 minutes ago, Paul M said:

I have the Celestron 127 Mak. Not sure how they compare performance wise but it's also 1500mm f/l.

I'm new to imaging and had a quick session with with the Mak on my NEQ6Pro mount and my unmoded Canon EOS 1200D last month. No guiding but have a ASI120mm guide cam on order which I will use with the 50mm finder rom my big Newt  At 1500mm it's long enough! so no Barlow needed.

This was M57 with 12 x 120 seconds at ISO 800 (Using APT on my laptop) and roughly processed in Photoshop. I'm quite happy with it as a trial run. The NEQ6 is more of a mount than needed so I expected good subs anyway.  I just srewed the camera to the back of the scope and focussed it (using APT live view) and set it off!

Certainly a very usable scope for Smaller DSO's but no good for M31 (Andromeda Galaxy). 

That’s great thanks I have the 120mini it came with the ZWO 30mm mini scope (as a bundle) just worried now that it won’t be powerful enough to guide the scope. 

22 minutes ago, catburglar said:

I wouldn’t use a barlow- at the native 1500mm focal length you’ll be imaging at approximately 0.5 arcsec per pixel- I’d be surprised if you can get your auto guiding setup to get the best from that sort of scale. I’d keep the native resolution and bin the pixels 3x3 (or 2x2 if you have really good seeing and excellent guiding)

Hi ok thanks but would you mind explaining what you mean in the last sentence about native resolution etc. Would the guiding camera be ok for my mak IRC’s all from ZWO to work with the ASIAIR pro. 

Ok that’s great guys Thankyou. I have looked at the calculator by using a 2 x Barlow gives a bigger picture for example of the whirlpool. I’m guessing that would be better rather than not using one?. 
sorry I’m new to Astro photography 

2 hours ago, Victor Boesen said:

Hi Matt

You'll need quite a solid mount shooting at that focal which will probably be the hardest part. Because of the focal length you'll also be limited to smaller DSOs like planetary nebula and star clusters but they often look good at these focal lengths if done correctly;)

Lastly, you will not need an eyepiece. I highly suggest shooting at prime focus when doing astrophotography.

Hi Victor I have bought the ioptron cemp-25 it was recommended by FLO due to its accuracy they also suggested a 32mm Plössl which I have also ordered so do you suggest not using an eyepiece at all then?  

Hi can anyone give advice on the best way I can use my mak for DSO photography. I know they are great for planetary work but not so good for DSO. I am using the ASIAIR pro with asi153 camera and the 120 mini for guiding with a 32mm plossl eyepiece. 
thanks 

Matt 

1 hour ago, rob_r said:

FLO have two bundles at the moment which I am considering as I have a Mak 127 also, https://www.firstlightoptics.com/guide-cameras/sky-watcher-9x50-finder-adapter-zwo-asi120mm-bundle.html and https://www.firstlightoptics.com/guide-cameras/sky-watcher-evoguide-50ed-guidescope-zwo-asi120mm-bundle.html. I can't really offer a definitive advice as the focal lengths of both scopes need to be considered plus the ratio between them which I gather should be under 4. I'm sure more experienced members could elaborate further for us both on this regarding the arc seconds per pixel and need to read up further on differential flexure. However, entering the information into this calculator for both bundles seems to be a good ratio, https://astronomy.tools/calculators/guidescope_suitability. But you could imagine that a guide scope could in theory be physically longer than the main scope. 

Hi Rob yes I have quickly found it’s a bit of a mine field when it comes to purchasing filters, eyepieces etc so these forums are a bit of a god send with astronomers with a huge amount of experience. 
I did see those but also saw this one 

https://www.google.co.uk/amp/s/h5.aliexpress.com/item/32845131969.html

you can get it for around £80 in the uk. The drivers are from the ASIAIR website so used with a skywatcher scope is a slightly cheaper alternative. 
i have ordered the ASIAIR pro and camera to work with my iPad so want to make sure it works with that kit and their app. I know the one from FLO will work as the camera is from them. Just seeing if there was a slightly cheaper alternative as my budget has gone out the window with recent purchases 

Hi I am after some advice. I am looking to purchase a guide scope for my 127 mak. Can anyone recommend a cheap camera and scope or even better a bundle that I would purchase. 
many advice would be appreciated 

regards

Matt 

7 hours ago, Messy Hair 101 said:

Amazing what you can do with a camera phone now! On the second one, it does look a bit soft. Is it possible to stack pictures using your phone? You can take a video but I don't know about the file formats. Just make sure it's as sharp as you can get it too. It's harder to do with a full moon. The terminator on a partial moon really helps you to see details and fine tune your focus.

Hi I don’t think you can stack photos with an iPhone but I did struggle getting the full moon Image to focus I’m wondering if it’s because it’s so bright even with a moon filter and the phone struggled I did use an app called slow shutter specifically designed for night photos plus I can actually take the photo by using the same app on my iwatch so I don’t have to touch the scope at all which minimises any shake 

Hi I have taken some images of the strawberry moon with my 127 mak using nexyz phone mount using iPhone 10 Xs max. I have then used an app called infinity photo on my iPad Pro to help sharpen the images.
Any feedback would be appreciated.

I am waiting for the asi air pro and the ASI 183MC ordered from FLO so cant wait to get some images with that set up. 
 

Regards 

Matt 

15 minutes ago, Bobby1970 said:

You can get USB C OTG cables. Also if using ZWO Camera download AsiCap. 

As long as there's an iOS version. 

Hi Bob that’s great thanks for the advice will take a look 

Matt 

1 hour ago, Neil H said:

Does the iPad not have a usb , I know that a kindle you can use a micro usb to standard size usb ,so you may be able to get this lead to work you iPad then down load nightcam on Apple store this works with most cameras then you may be able to use ASL camera from FLO

Hi Neil my iPad Pro has a usb-c connector. I know Apple sell a usb to usb-c connector but just don’t know if for example a ZWO ASI 224MC Color Astronomy Camera would work through this so I can use an app to take video or phots 

10 minutes ago, DaveL59 said:

no idea re apple but most handheld devices don't operate as host controller for USB and would need a OTG type adaptor in order for an external USB device to work (such as a USB memory stick). Could be that their USB-micro adaptor serves that purpose but driver support in the device could well be limited to storage and audio. Do you have a regular USB webcam you could try before spending on something that may well not function?

Hi unfortunately I don’t. I would just be nice to connect a camera to my iPad Pro, through the usb-c connector rather than having to splash out on a laptop which I don’t currently have. 

The new iPad the new micro usb connector I know Apple sell usb to micro USB adapter just don’t know if a camera will work through this type of adapter