Jammy

Rather than release the clutches I point mine to a star near the zenith, which is easy to do with goto.

I don't think there is a right or wrong way really.

Hi all.

I've created my own darks library for my ASI1600mm Pro.  Various gains and various exposure times all at -10 Celsius.

I'm just wondering what people do with them?  Once you've taken darks and processed an image you get your master darks.

Do you guys just keep the master dark, in a master darks library, or do you process your darks again each time you stack a new image?

I'm just thinking to save storage, could I discard the dark sub frames and just keep the masters?  I don't want to throw them away if that is wrong though.

Also, with this camera I take dark flats rather than bias frames.  Because the scope is covered, do I need to do dark flats each time I take flats?

I have an even illuminated flat box which I always use at the same exposure lengths.  I guess the only thing that could vary is the gain value.

I understand the need for flats every time you change focus, for each filter etc., but if I'm using the same exposure time can I just use a previous set of dark flats as long as the camera settings are the same?

If this is possible, can I then create a dark flats library for any difference in gain values?  Not sure if I gain values affect dark flats though.

I've read that back, and that's a lot of questions!  All help greatly received.

Thanks for the response.  I've not used PI, and can't really comment.  APP doesn't cope very well with the banding and that's why I've noticed it.

I have the same issue even at bortle 6/7.  My L subs start to blow out above 20 secs, that's why I wanted to lower the gain value.

3 hours ago, Knight of Clear Skies said:

Below unity gain I think your camera is discarding real data

I didn't know that.

I've only tried because I've seen other people getting good results at gain zero.

I'll be completely honest, I've no idea what it is supposed to do if anything.

I've asked the same question on one of the ZWO forums and I've been told the camera does not perform well at gain zero and it's been suggested using at 75 gain.

I tried it at 75 gain last night, but I'm just running off some darks and flats to see if its any better.

I did the Sharpcap sensor analysis and smart histogram and it gave 138 for unity gain (ZWO say 139), and 59 for high dynamic range value.  I'm not sure what HDR is or does.  I'm a novice when it comes to these type of cameras.

Also, having gone through the whole learning curve of imaging from web cam, dslr and cooled cam with PC, drift aligning etc... I can't believe how simple this makes everything.  Have a little patients with it and most of all enjoy!!

I've been trying to image M51 with Evostar 80ED and ZWO ASI1600mm Pro cooled camera.

I've used the camera at unity gain at -10C many times and it's always worked really well.

As an experiment, I've decided to change the gain to zero to see what difference it makes.  I've also added a IDAS D2 LPS filter and increased my exposure time from 20 secs to 60 secs.  In bortle 6/7 skies data was blowing out above 20 secs of Lum before I got the LPS.

All my images are now coming out with vertical banding.

Is this due to the camera gain value?

I've added some shots of what I'm getting out of the camera:

Single Light Frame

Master Dark

Master Dark Flat

Master Flat (ignore all the dust spots!)

Output file from APP without any further editing.

My flats and dark flats are taken with a light box at around 1/10th sec, is that too short?  I'm getting the required 20000 ADU value at that for Lum.

I've not noticed any problem with the camera at unity gain,  but having seen other people using gain zero for images and thought I'd try it.

Any help would greatly be appreciated, thanks.

They've not updated the user manual from the first version yet.

It is very easy to use once you get to know it, and all the steps are pretty much in sequence.  I'd have a play about with it and get to know it.

I know that's not what you wanted to hear, sorry.

There are lots of youtube videos on how to use it, and also a ZWO ASIair FB group which is pretty good, ZWO use it themselves to communicate info about the device.  (Not sure if I'm allowed to say that in here - mods feel free to delete this if that's against the rules??)

The manual is found on this page, but it is out of date.  I believe they're working on an updated version:

https://astronomy-imaging-camera.com/manuals-guides

Thanks for the suggestions guys - I'd seen a few options online, but it's always better to get recommendations.

I'll give these a try.

Hello

Can anybody recommend a .fits viewer for windows.  I already have fits liberator 3 but wondered if there were any others?

I'm looking for something that allows you to easily flick through frames to check them, and also has a decent size image window.

Maybe I'm asking for too much...

On 20/02/2020 at 21:34, Graeme1858 said:

Hello

I put a cardboard and duct tape flat frames light box together recently. After reading this very informative thread I can see that my effort is definately a mark 1.

Foam board is the way to go!

Regards

Graeme

Foam board is surprisingly strong.  Still using my light box and getting good flats.  They sell foam board and hot glue guns in 'The Range' if you have one near you.

Right!

I've tried fitting the dovetail bar that came with the NEQ6, but unfortunately the drilled holes are too small for the bolts that came with the Evostar 80ED.  Can anyone recommend a longer dovetail bar that will accept the 80ED tube rings and bolts?

I could try drilling out the holes on the bar which I have, but I'd rather not attempt it!

Thanks for the comments.

I've moved the OTA as far forward as I can within the tube rings, but it's still not enough.

I do have a longer spare vixen dovetail bar which came with my NEQ6 mount, which I've never used.

I'll have a go at swapping the dovetail over and moving the OTA as far forward as possible.  See if that helps.

From your answers I gather that balancing in declination is just as important as it is for RA when imaging.  I thought it must be, but always best to ask.

When I'm trying to balance my telescope for imaging does it matter that I can't get it balanced in declination?

I can get the right ascension to balance fine through the mount and counter weight.

With the telescope being relatively small (Evostar 80ED) with OAG guide cam, main cam, electronic focuser and filter wheel attached I can't physically move the scope forward enough within the tube rings to get it to balance.  It isn't greatly out of balance, but then I'm not sure how important this is.  If I helps to have this balanced, is there any way of adding counter weights to the front end of the scope?  Do i need to get different tube rings/dovetail?

I'm just wondering how others have managed to get around this.  All comments welcome 😀

I asked about dew heater control in the ASIair facebook group and was told by the group moderator "the intention is to have controllable DC ports on the pro - we are still waiting to see the exact production version so will have to wait see how that looks".

I guess nobody knows!!

On 11/12/2019 at 13:37, Space Oddities said:

From the specs that leaked, there doesn't seem to be any output for dew heaters, like there is on the Pocket Powerbox. That's a pity! I was in the same situation, and went for the Powerbox instead, figured it's more future proof too.

I asked about dew heater connectivity on the facebook group and was told that dew heater connection is included.  No idea if that's true or not though.

I'm going to put my order in, my laptop doesn't like the outdoors!!

Looking at the known specs, could anyone tell me if the ZWO EAF (elec. auto. focuser) can be powered direct from the ASIair, or does it still require external power?  Same goes for the cooler fan on the ASI 1600mm Pro?   I'm hopeless when it comes to electronics!

Thank you.  I didn't know the Black Diamond was the same scope.  Every day is a school day!

Sorry if I'm repeating a post anywhere, but I'm trying to find out if anyone has a Sky-watcher Evostar 80ED and a ZWO Electronic Automatic Focuser.

Are these compatible?  The EAF manual mentions a few Sky-watcher telescope ranges, but not the Evostar.

I've done several web searches but can find nothing.

Maybe we should have a compatibility thread... just a thought.

Thanks guys, I'll take a look.

You've been really helpful ?

Thanks for all the replies guys.

I managed to make the flat frames light box at the weekend.  I used @Oddsocks method for testing the light distribution, which really helped spacing the perspex sheets.  I also needed to add some inner foam board to diffuse the light because of a slight light drop off at the very corners of the box.  I probably wouldn't have spotted this without the photometer, to the naked eye it did look very even.  I also did a stretch in photoshop as described by @Horwig.  That idea came to me after I'd glued it all together, and before I read your reply!

I've sized the front circle large enough to fit over the front of the C9.25, and I've also made an insert that will allow me to use it with an Evostar 80ED.

I'm now waiting for a dimmer switch to arrive that I found on eBay, then I'll be ready to start taking flats.

First time I've used foam board, surprised just how strong it is ?

12 hours ago, NGC 1502 said:

 

This could be a useless comment because I’m not at all familiar with what you’re constructing.  But instead of gluing, could you use removable screws instead, enabling easy dismantling for modifications ?   Or is there some reason that you must use glue  ?

Ed.

I'm going to make something like this photo (image stolen from Richard McDonald's website).  Foam board doesn't take screws very well (if at all), but can be jointed with a hot glue gun.  It's the distances between the inner baffles that I'm trying to space correctly before I fix it all together.

3 hours ago, Davey-T said:

The white opaque plastic in my 10"SCT light box rests on the front of the scope, seems to work OK, I've seen similar ones.

Illuminated from the rear with four dimmable halogen bulbs

Dave

Looks good Dave.  I'm hoping to make mine compatible with my Evostar ED80 too by allowing a sleeve to fit within the opening for the C9.25

I'll post a pic when I'm done ?

@symmetal @Oddsocks

Many many thanks for the detailed solutions.  You've excelled yourselves ?

I'm going to construct the box this weekend.  Fingers crossed it will all work as planned.  I've drawn a CAD model of what it will hopefully look like.  Now to put the theory into practice!

I'll give feedback when I'm done, but only positive ?

I'm making a flat frame light box for use with my C9.25 SCT using the traditional method of light behind opaque perspex sheets, and set within a foam board box.

Large EL panels just feel too expensive at this moment in time.

In order to make sure I've spaced the perspex correctly before I glue everything together, is there a way of checking how even the illumination of my flat frames are?

I've seen on forums where people have posted flat frames with numbers, contours etc to show how even the illumination is, but I've no idea where these things are done.  Do I need specialist software to do this?

Thanks for any help

Thanks Steve.

That's just what I need. I didn't know those adapters existed. I did wonder if you could buy a splitter - mount, dew heater, and now the Bluetooth... power tanks need more sockets!

Just as an aside, my adapter works without the Null Modem.

Thanks for posting this thread

The BT Link bluetooth adapter is the same as the one on the USConverters website.  Are you sure you have the correct baud rate?  You can change the baud rate by downloading Teraterm.exe from the linked page (near the bottom of the screen).

www.usconverters.com/index.php?main_page=page&id=15&chapter=0

Be careful to only install Teraterm, as other software asked if you would like to install it also.  I've no idea what it is, but it isn't needed (might be malware).  I've uninstalled all the software now that I'm finished with it.

If you do have the baud rate set correctly at 9600, make sure the Master/Slave switch is also set to Slave.  Within the Teraterm software type 'role=?' and it will respond either M or S to confirm this is the case.

I should have mentioned that the PC software will only communicate if you have the DCE(F) / DTE switch set to DCE(F).  When you are using the device with your scope set to DTE.

Jonno, I've just read through all your post again (now that I've typed this out).  Why do you need the adapter if you have Skyfi?  Doesn't Skifi use a wifi signal instead of bluetooth?

Is the cigar/lighter plug connected to a 12v powertank, or is it a separate  5v 500mah battery?  Sorry, I'm not entirely clear what you mean.