Adam J

If it was me I would email them directly if you want a fast responce, I am sure they will see this but it might take longer. questions@firstlightoptics.com Adam

looks like too much spacing on your corrector to me. Also maybe the corrector is introducing some CA, you can tell lots by looking at the indevidual RGB channels.

I have AD Ha Sii and Oiii all in 5nm I used to have Baader filters, the 5nm are a significant upgrade just due to halos but in my case I would say the image was also brighter in Ha with better contrast leading me to wonder what the peak transmission on the Baader ha was. I am under class 5 sky and I dont feel the need to upgrade to 3nm, however I paid £180 for my 0iii used but as new, £250 for the Ha new, and £330 for the Sii new. I acquired them in that order, at the current prices I would give AD and Chroma a miss unless you have a tone of spair cash and nothing else to spend it on. Lol just worked out that at current prices I could sell them second hand and actually make a profit.... Adam

Honestly if you can see any difference at all between 50 and 70 then I would be shocked. Hence if the default is 70 just leave it there, more improtant things to be worried about. Probably not worth putting the effort in to test it as the advantage of lower bias (at gain 100) is an insignificant increase in dynamic range. Adam

No problem glad its sorted out. Adam

Deeply envious of you this is my dream mount, ill never afford one though. Adam

What model is the smaller of the two?

Most councels are quite good about this sort of thing so its always worth asking.

At gain 100 you have huge dynamic range so I would just stick it at 50 and be done with it as its sufficiently high to be sure to prevent black clipping and your not going to see any real advantage to lower settings. Adam

Wow and I was thinking I was unlucky to have to wait 40 days last Octobre. Adam

I have a Esprit 100 but part of me thinks I should have held out for the 120. Guess it depends on what you want to image, the 120 is better for galaxies no doubt, the 100 for nebula. However, at the time it was between the 80 and 100...the usual always wanting a bigger scope than the one you have issue. Adam

I would not think so, not with that sensor size anyway. Adam

Sorry I meant the travel length. You will have no issues.

The focuser tube? I dont think so as there would be nothing to stop it from falling out if you cut it down. Adam

If its the Explore scientific then its F7.5 and you will have no problem with the 2 inch focuser and that sensor. The problem i see you may have is insufficient travel on the Baader focuser as I believer that the original focuser requires the use of extension tubes to reach focus and is configured that way to allow the use of bino-viewers, have you accounted for their use? I am not sire about how you would connect a 3 inch reducer to a 2 inch eyepeice holder? Adam

Huum, I think that tube is too long for the 130PDS at focus it will be sticking into the tube and taking a bite out of your stars/ creating additional halos. I think they reccomend the 35mm tube for the 130PDS. Adam

What is the tube length on your moonlight? Just wondering if the SW CC will push it back into the light path. Also I would check your mirror clips are not too tight. Adam

dam What coma corrector are you using?

Because I completely meant that literally...

8mm steal? Hope you have a crane to lift it into place. Mine was 1/8 of an inch and worked just fine, and I know how heavy that was.

If you have a F5 Skywatcher PDS Newtonian then yes.

The ASI533MC Pro is the camera you are looking for.

Looks like a good example to me. I am shocked you managed to get the HEQ5 pro to carry it, I tried and failed to get it to work on mine and changed to an AZEQ6 GT. Guess I will add you to a long list of people i know of with tilted sensors on the ATIK460EX.

0.6-0.8 RMS in good seeing (80% of the time), of course in poor seeing its upto 1.2 RMS (1 in 8), on a really really good night 0.5 RMS (1 in 50). With an RMS of less then half the image scale I dont really see any further improvements in image quality though. So with the 130PDS and the 533 I would think that optimal guiding will be 0.6 RMS or less. Hence you would need an guide RMS or around 0.4 to get full benefit from imaging at 0.77....I have never got down to 0.4, hence its at that point that you need a very serious mount and very good seeing. Adam

You will be able to guide well so long as the guide camera scale is less than 4-5x the image scale. My image scale is 1.4 and my guide camera is 6.7 and I managed this (and with a mono camera guiding needs to be even tighter). Adam