View Full Version here: : Lodestar MaximDL Guiding and Dithering
01-05-2012, 09:37 PM
After a fruitless first attempt at getting a Lodestar camera to work with MaximDL I decided to read all the manuals and google it all.
My free trial period ran out so I had to pay for MaximDL as I have no real choice as it supports FLI gear.
Tonight between clouds as usual got it all working. MaximDL sees the Lodestar and what is even better guides the PMX mount very nicely. The calibration was too easy as it was a bit like PHD.
I did a few test images and the dithering works really well.
I will not bother showing any images as the thin cloud nearly stopped even this simple test.
Another small step for a delusional old fella.
01-05-2012, 09:43 PM
That's great Bert. Getting guiding to work is a big step forward.
Just so you know you can use FLI gear with CCDsoft with the Software Bisque camera plugin.
It does not access all the features of the camera though, like setting the 2 different download speeds, or RBI control. I use neither anyway.
Lodestar also works in CCDsoft although it won't use a library dark when autoguiding. It will do autodark.
Does Maxim allow dark library subtraction in the Lodestar when autoguiding?
There are also some really good free plugins for autoguiding with Maxim. Averaging out 2 guide stars is one.
01-05-2012, 09:51 PM
Yes greg if you change the exposure of the guide camera MaximDL asks you to cover the camera for a dark.
I am amazed at the sensitivity and signal to noise of the Lodestar.
I have not even tuned any parameters and all seemed to work well.
01-05-2012, 09:56 PM
Bert, This link (http://tech.groups.yahoo.com/group/MaxImDL/message/48859) to the maxim yahoo group outlines how to set up a lodestar for full calibration including a bad pixel map in maxim.
He has setup a number of dark groups for various exposure times, but maxim also scales darks so in a pinch you could use a single group of darks with an exposure time longer than the maximum you are likely to use and maxim will scale it to suit.
02-05-2012, 10:51 PM
Bert as you come to grips with maxim you will learn to love it. It is very powerful and only has a few annoying habits like guiding best on 2 x 2 bin. Make the autosave your friend, check out the scripting and have a look at the array of plugins that have been developed for the program. Best feature of the guiding is the ability to change settings on the run which is really helpful if conditions change or you need to rebalance the rig....it gives you a little extra time so to speak. Easily the best most complete astro program out there and I love the way it gets on with everything I have plugged into the computer. Using the SBIG ST-i means I don't even have to cover the guide scope when taking darks for guiding, just a simple dark and it is automatically applied to all the subs there after. Good stuff.
04-05-2012, 06:50 PM
Thanks Robin and Mark.
Now I have the full version of MaximDL widoze does not ask me if I want to let this program fiddle with my hard drives!
I may be imagining things but the options are different. There is now an option for a single slot (filter) to be recorded as group before the next filter exposures. It seemed to cycle completely through all selected filters taking one exposure per filter at a time.
The supplied USB leads by FLI are far too long. I was having an intermittent total hang on download of an image with MaximDL with the supplied 5M lead from computer to the PL16803 camera.
A USB hub and a short shielded (ferrite) cable fixed this annoying glitch.
I await clear skies to be tripped over by more problems.
At the moment we are taking darks at -35C. The Peltier power load is only about 90% at an ambient of just over 15C.
By the way 'we' refers to my dog and me he follows me and watches what I do. When ambient gets below about 8C he sensibly stays inside.
04-05-2012, 08:36 PM
To be fair Mark almost all cameras guide best on 2x2 guiding.
05-05-2012, 01:50 AM
Yes Greg but Maxim likes to home in on hot pixels for guide stars if you let it :P. I find it is worse when I use 1 x 1 bin. There are far too many good features in maxim to let that worry me.
05-05-2012, 02:00 AM
Bert that does sound new from the version I have anyway, will have to update. Currently if I want a set of subs from a single filter I have to deselect all the others or it will cycle as you have said in autosave. I solved the lead drama with the mount hub pro, my longest lead is only 0.8m.
05-05-2012, 09:30 AM
Have a look under options on the exposure dialog. There should be a group by slot option for the filters. If that's on then it will shoot all red then all blue then all green ....
It looks like it's only active with a camera connected. There is also a minor bug here, click on options and the menu will only pop right of the arrow so if the dialog is too close to the edge of the screen it closes real fast. Move the dialog to the left a bit :)
02-09-2012, 01:50 AM
How long did it take you to learn Maxim DL?
I have the same problem as Bert.
I tried out my new CCD camera for the first time tonight.
I got it to focus on all 5 filters & download pics.
I didn't have any luck with guiding using Maxim DL & a Lodestar -
so at the moment I am trying to learn Maxim DL but it
is an extremely difficult program to use.
PHD guiding is so simple to use in comparison.
The first time I used PHD I was guiding in 5 minutes
without having to learn anything.
Tonight - Maxim DL guiding cost me 3 hours & I got no where.
Maxim DL - the most difficult program to use that I've ever seen in my life.
02-09-2012, 07:13 AM
then don't waste valuable night time experimenting with Maxim and guiding. Use PHD, get the images you want and be happy.
On those full moon nights, or nights where there is a thin layer of cloud which makes imaging unsuitable, try it then.
There is nothing wrong with PHD, nor Maxim, each do things very well, just differently. Once you guide with Maxim, you can always have PHD available, if you want.
02-09-2012, 09:00 AM
Most guiders will need autodarks to remove hot pixels to be useful in guiding. Otherwise you will find that the software often picks a hot pixel instead of the guide star.
With Maxim I believe you can record a dark and have it used in guiding doing an auto dark subtract using this saved dark. You can't do that with CCDsoft. So you would need to do that as Lodestar can have hot pixels/artifacts that need to be dark subtracted out to be useful.
You can also try subframing the image to pick a clean part of the image to guide on with a decent guide star.
STi is best as it has a shutter to allow dark subtractions in CCDsoft, no artifacts, very clean images.
I think its one of the best autoguiding cam out there at present. ST402ME is more sensitive and is cooled reducing noise and so doesn't need autodarks and is another excellent guide camera. It also has a shutter for darks if needed.
SBIG is the leader in autoguiding technology by far.
02-09-2012, 09:05 AM
Thanks for your reply.
Last night was just a test to see if I could get the new system working -
it was a full Moon anyway.
I did preset the focus etc of the Lodestar using PHD guiding to make
sure that it was all working before using Maxim DL.
Unfortunately I have to use Maxim DL guiding because I want to
be able to dither every sub-frame.
I found a video here which explains guiding with Maxim DL.
There is also another one here but it's in German (which I don't speak )
The German one at least showed a window called "Screen Stretch Window"
which is essential because otherwise all you see is a whole screen
of white noise (snow) coming from the Lodestar camera.
I didn't know about that screen.
I did try histogram & curves last night but just moving any cursor
the smallest amount would make the view screen all black &
it would not reset to the snowy screen without
exiting & starting up Maxim DL again.
The first video at least explains that you
don't run the Lodestar guide camera from the guide window -
you switch to the exposure window & click camera 2.
If I'd known both those points I might have got it guiding.
Neither of those 2 points are intuitive.
At the end of the night I tried to take a photo using PHD guiding but
it didn't work well when Maxim DL was running -
it kept losing guide stars.
The mount - although drift aligned had a much larger drift error
after 5 hours outside than when first aligned.
My NEQ6 mount is very bad at doing that & I never figured out why
after many years.
I also found that Maxim DL doesn't see a camera if you use
use another USB port.
I had to use another port because my Lodestar only works on one particular port.
I had to reload the drivers for Maxim DL to get it to see the main camera.
I wonder how anyone gets Maxim DL to work on a USB hub?
I may also have a bit of wobble on the guide camera due to the longer image train
needed by the QHY9 camera, filter wheel & Lodestar
The load on the focuser is different compared to
my old DSLR camera using a Lodestar.
That effect could be giving me guiding problems.
Next time -
I will have to get it guiding properly with PHD guiding first
just to see if it can guide properly.
Anyway - a useful first light test of the camera -
at least I have some ideas of what the problems are.
Part of the problem was me - not checking the internet for a tutorial
on Maxim DL guiding for training before starting the first time.
I never thought it would be so hard.
There is no video tutorial on dithering but I found a link that expains it:
Comments are very welcome from anyone.
02-09-2012, 10:13 AM
I run my guide camera from the guide tab - only time I have run it from the exposure tab is to take a run of darks. You then load these darks into the calibrate routine and enable "full calibration" in the guiding tab. I agree the software isn't 100% intuitive, but it's like most software in astronomy - full of unusual terms.
The picture always looks very grainy vs PHD, but the guiding is fine. I'll have to try multi-star guiding and see if that improves things for me.
02-09-2012, 01:27 PM
If you look at the video - It looks like you need to set the camera up
to take exposures to find guide stars & focus - then you go to guiding.
It looks like the Screen Stretch Window fixes the snowy picture.
02-09-2012, 01:42 PM
On my version of maxim there are three radio buttons towards the right hand side of the guide window: expose; calibrate and track. Use the first to take an image, the second the start a calibration and the third to start guiding. The histogram will tidy up the image, but it usually reverts to snowy on the next exposure. I usually have success with it automatically selecting a guide star, so I just ignore the snowy picture.
11-10-2012, 08:11 AM
I have adquired a Starlight Xpress SXV-AO-LF Large with a lodestar.
I wanted to use these equipments with Maxim DL V4,but I have had some troubles,the program it doesnt recognize the lodestar.
I have heard that is necessary to use the Maxim DL V5.
Could anybody help me?
11-10-2012, 09:43 AM
I use Maxim V5 and am not familiar with V4 but I would imagine that you would need a different SX driver (from SX). I am just starting to get my Lodestar/SXAO-LF to work and Maxim seems to be the only software that can use the combination. It was a significant step last week when I got the automatic Full Calibration to work with the Lodestar guide images so it can be done.
11-10-2012, 04:47 PM
So does CCDsoft so no difference there. All these guide cameras need autodarks. My ST402ME which is cooled usually does not need autodarks but very occassionally it works better with it.
CCDsoft had a hot pixel plug in from a 3rd party. It did a good job of removing the hot pixels. But it disabled auto selection of guide stars which was annoying at times.
11-10-2012, 05:00 PM
I am afraid that I will need upgrade the Maxim DL V4 to V5
12-10-2012, 07:37 PM
What am I not understanding here? CCDSoft can do bias or dark subtracts for the Lodestar using an image reduction group (see "CCDSoftV5->Image->Reduce->Image Reduction->Autoguider" and "CCDSoftV5->Take Image->Autoguider->Image->Reduction bias, dark, flat->Group Autoguider"). I do exactly that with CCDSoft to eliminate hot pixels. The Lodestar doesn't work at all as an autoguider if you don't eliminate those pesky hot pixels.
vBulletin® v3.8.7, Copyright ©2000-2013, vBulletin Solutions, Inc.