Color stacking without a filter wheel in Maxum DL

[carl20171]

Hello,  I am using narrowband filters without a filter wheel and  Maxum DL wont let me choose a filter in in the autosave tab. I am naming the filters with a suffix in that column so I can identify each photo. What is the procedure to convert to color? Do I stack first. I tried that and then it makes one image so when I go to color convert it only seen one image and thinks there is nothing merge or convert. When I try to convert to color in the stack window it lets me choose RGB in the select tab in the filter box and file names but when I go to the color window that shows 1, 1, 1 on the RGB that whole page  is greyed out since I didnt use a filter wheel? i guess it cant identify the images since it is not in the fits header or something like that.  I have HA O3 and S2 images, can anyone advise on the step by step procedure to stack and make the color come out in Maxum? I am using a monochrome camera. 

[steppenwolf]

You need to stack the individual filter images into three stacks, Ha, OIII and SII in three separate procedures. Because you haven't used a filter wheel, the FITS files don't hold the correct detail to automatically combine the correct sets. Save each of the three stacks with a suitable name to identify them.

You can then use the Combine Colour option from the Colour tab to produce your 'RGB' image. You have some choices to make here with regard to which filtered data you want to map to which colour channel:-

Ha to Red, OIII to Green and SII to Blue is a very conventional way but for the Hubble Palette you would map SII to Red, Ha to Green and OIII to Blue

[carl20171]

I will give it a go. Thanks much. 

[AndyUK]

Because you haven't used a filter wheel, the FITS files don't hold the correct detail to automatically combine the correct sets.

If you wanted to, there is actually a way to do this... 

When you go into Maxim and choose camera control, I have camera 1 setup as my imaging camera (using Artemis HSC).  There's a button underneath which says "setup filter".  If you left click that, you can then select "manual" from a drop-down box, which then allows you to manually type your filter names:

When you connect the camera(s), you can then select your required filter from the drop-down list you manually created under "filter wheel" on the Expose tab:

And when you go into the Autosave screen, in the filter column, you can again use the drop down list to identify the filter.

This then enables Maxim to insert the filter name into the FITS data and you can then use Maxim's automatic combine facility .

[steppenwolf]

Nice solution, Andy!

[carl20171]

That worked like a charm. Thanks much to all. The manual setting was the trick.  Andy I noticed you have SX universal setup on your screen shot. Do you use a loadstar for guiding? If so I am having some trouble with my Loadstar X2 and maxum. The pictures are full of white and black specks like the gain is too high on the camera. When  I take a dark with the loadstar software it is black but switch to maxum and it is an evenly cover pict of black and white specks? Any ideas?

Thanks again for the fix on the filter wheel. 

[AndyUK]

No worries... .  I'm luddite - I don't trust technology and have therefore never made the switch to a USB filter wheel...  Okay, I don't get much sleep on those rare occasions when we do get a clear sky, but as I can't trust our weather in the UK, it's no real effort to put coat and shoes on and go outside to change filter and re-focus (and check for clouds!)

I do indeed have a Lodestar (albeit not v2) which I use with an OAG (on either an MN190 or 80/f4.5 APO) on a pier-mounted NEQ6.  I have to admit that the on-screen view through Maxim of a (say) 3s exposure looks pretty rough compared to when I used to use PHD (v1) - I was a little perturbed about it at the outset, but as long as it calibrates and I can select a reasonable star to guide on, it seems to work fine.  Even at 1000mm FL I can get guiding at c. +/- 0.2px and of course it's even tighter at 360mm.

Unfortunately I don't have a screen grab of a typical guide image exposure to post, but as I'm picking a field off an OAG prism, there's every possibility it may look even worse than what you're seeing through a "proper" guidescope(!) but do you have a guide frame you can post up... just for comparative purposes?