Adam J

The colour balance might be but not the pixel level sensitivity. Hence why raw OSC astro images usually come out green before colour balance is applied. But you can't get rid of bloat by balancing colour it's baked in to the image. I promise you that the QE of a OSC is not 10% in the blue. if we see green stars in a image something is wrong and that's what you would get if it worked as you suggest.

No that's just the human eye response. And if the object is blue then the lum will have no red in it at all will it. So it also depends on the colour of the thing your imaging as well. Most lrgb filter sets try to balance each channel against the sensitivity curve of modern sensors and so white light will be close to evenly split between the three channels.

Yes they are famous for creating tilt some cheaper ones are much worse than others.

I would have to see an image to know for sure. But with a DSLR its normally the T-adaptor that causes tilt. Its not actually a very good way to attach a lens to a sensor. Adam

For what scope? For visual or imaging? Have you caractroised how bad the CA is? Adam

I have been doing some testing with a Astronomik L-3 Luminance filter to see if this mild filter is able to remove the small blue bloat that the FMA 180 has. I have heard that people have used the baader semi-apo and the finge killer filters with this scope to good effect in reducing the blue fringes on brighter stars. However, it has been my belief that such filters are unnessasarily harsh for this scope and more than is required to remove the amount of bloat I have been seeing. Hence I have tried a combination of Astronomik L-3 in line with my Baader filters to slightly clip either end of the spectrum. Here are my results for the blue channel with and without an Astronomik L-3 filter in line with my Baader Blue CCD filter. First with Baader Blue Filter only: And then with the Astronomik L-3 and Baader Blue Filters in series. (2 inch L-3 on the nose and 1.25 inch in the filter wheel). I would call that quite a dramatic effect / improvement! You lose a little bit of signal in the blue channel and less in the lum channel in comparison to without the L-3 filter, but not that much so I see it as a worth while trade off given Green and Red are vertually uneffected. Just increase blue channel exposure by about 25% and keep L,G,R channel exposures the same, colour balance remains good. Target was M44. Clearly a large crop this being presented at greater than 1:1. I expect that this would produce a good improvement in a OSC camera too. Star FWHM is now extreamly close across all four LRGB channels and so I am hopeful of some good perfomances to come. Hope this is usefull to my fellow ASKAR FMA 180 users. Adam

Its beacause SW place no current and reverse voltage protection on their boards and this one has a none standard aviation connection so everyone messes it up and blows the board up. Adam

I would not call £23 between the two that significant? What prices are you looking at?

Adjusting the worm gear wont so long as you take care. I would consider re-greasing to be mantainance but you should take advice from your supplier on that. Maybe try the former before the latter. Adam

I completely stripped my one down the grease that SW uses may as well be glue. Also as above the worm can be too tight and stick and you should get the latest firmware. Its a mount with nice potential but horrible quality control issues. Adam

In general stepper motors will make such a sound at low speeds. You should just make a recording and post it here.

Ok I'll distil all that down to this. There is no such thing as none random noise or noise that is not totally random. If it's not totally random darks will remove it period so long as you have a sufficient number of dark frames in the stack. Bias instability in short exposures is not a problem for CMOS you just don't use bias. You use dark flats and it's all great. Once you do this there are no random offset s on the cameras I have used. As for spectroscopy etc that's a small corner of the hobby and so it not a factor to 99% of people in this forum. Average noise will not be added to your images when dithering. It will have been removed by darks. That's why data pedestals and offsets exist. These are then removed during the normalisation stage in stacking. They just don't get through to the final image. The only time any of the effects you are discussing would appear is in very old sensors or via user error in selecting the wrong camera settings or calibration flow.

If it calibrates out its not noise though. Only fixed offsets can be calibrated noise is not a fixed offset (its noise) and hence cant be calibrated because its random. Adam

If you mount it on the dove tail I found it can actually rotate the scope in the rings if not perfectly aligned, as a result of causes guiding issues following autofocuser movements. Hence I changed to mounting it using the outer two screws. Much better.

This will be transformational for anyone who can afford it and the larger filters. I am just going to have to hold out for a the mono version of a 533 that I keep predicting will come eventually. Adam

Ouch, remind me never to over tighten my clutch. It will be metric so just measure the width with a caliper including threads and round to the closest milimetre. Adam

I am shocked that you are shocked.

You don't include counter weights in the payload limit of an eq mount.

I have done exactly this on my ASKAR 180 vlaiv but place the 2inch L-3 filter in line with my 1.25 filter wheel with baader LRGB. It effectively clips down the red and blue filters while keeping everything para focal.

outstanding work rod.

I had exactly that camera and exactly that modification and I can 100% confirm that it will work fine with the non CCD version, you even have a 130PDS which was the same scope as me. So you will be fine. Everyone talking about bloat above, he looks to be using a reflector...so what bloat are you expecting? The Coma corrector would not have a big impact. Now if you want to use it with a refractor I would get the CCD version just to be sure as the remaining filter will still allow a little more IR through than a conventional IR cut. Adam

Cool what camera did you use?

ZS73 for sure as the ES scope only uses FCD01 glass and will not be so well corrected assuming you are imaging.

So you have a preference for bum over...

Let me know if this is any good thanks.