Adam J

Back focus is something best judged by looking at the in focus corner stars in my opinion as out of focus stars will result in the corrector being in the wrong position. With a flattener reducer the image is only ever optimally corrected when in focused. If you mean with a in focus artificial star then even in this case the optimal back focus may change with for focus distances shorter than infinity although it will get better as you increase the distance to the artificial star. Adam

Sure you have tilt but I honestly do i see a little coma in the centre of the field and that should not be the case as the result of tilt alone. Best thing to do is a star test to examine the optical alignment of the scope. Centre a bright star in the FOV and then de-focus it until you have about 5 rings visible. Do this either side of focus blow it up and post the result and i will be able to say for sure if there is a problem. I use one of these at about 10metres to do this without having to wait for good seeing / clear skys. https://www.firstlightoptics.com/other-collimation-tools/hubble-optics-5-star-artificial-star.html Adam

Its a good camera, but i think if your target will fit onto a 533 then its a better camera. I think that the 2400pro is a great camera if you can afford one. Adam

I think it will work on both from what I have seen, but you will need to make sure. Adam

Great Image, just wondering about the reflections close to the stars, I noticed them on your Horses Head recently too, maybe try a shot without the reducer? I am interested in this camera so would be good to know. It may also be the lack of IR Cut as some AR coatings dont work well in the IR. Or was the subsequent horses head with one? Adam

Personally I would never attempt AP using the AZ GTI via the inbuilt WIFI and recommend that you get one of these instead. Its just not a reliable connection. https://www.firstlightoptics.com/sky-watcher-mount-accessories/lynx-astro-ftdi-eqdir-usb-adapter-for-sky-watcher-az-gti-mounts.html Adam

Its a front illuminated sensor and not a back illuminated sensor so its got lower QE in comparion to the 533 and higher read noise. Adam

Would kinda turn it into a much smaller 294 with higher read noise though for 80% of the price? Adam

In theory the larger pixels will deliver a slightly better signal to noise ratio. I dont recommend the ASI183mc pro in anything except very fast optical systems as I'm most cases your conditions and scope are unlikely to realise the resolution provided by those small pixels.

Yes that took is indeed flawed on a number of levels and I wouldn't use it either.

ASI533mc as it has no calibration issues with duel narrow band filters. Adam

@PadrePeace may be able to provide some insight here. Adam

no the 294 does not operate the standard RGGB pixel martix, it groups the pixels into 4 groups of 4 super pixels.

Get an AZ GTI much better in the long run due to plate solving / goto and it guides just as well in RA as the SA. Adam

there is no bin one for the OSC version of that camera, it only functions when using the mono version. Little surprised that you actually have the option. Adam

Cant really help more that to say that this is a common issue with the OSC version of that perticular camera and I am not sure what the solution is, you may have to look for older drivers. Adam

Don't know what you are trying to describe but there is nothing in that image that would have me worried.

For me there are only very few situations when I would choose that camera over a ASI533mc amp glow aside. What scope will you use it with?

Am talking about lateral dispersion not angular dispersion. But the point is that you can't just scale the lens as it needs to become disproportionately thicker for mechanical reasons. Could be wrong I'll look for a reference.

I think that one factor is that they have to make the glass thicker as aperture increases also increasing dispersion. Also the size of the airy disc gets smaller and the larger aperture supports more magnification hence the tolerance to CA is lowered.

So the interesting thing is that to my knowledge you can buy better colour correction in exchange for introducing polychromatic Spherical aberration. Also the smaller aperture of the technosky makes thing easier, but I would not be shocked if you told me that it was not the sharpest. None of that invalidated the test, just that you can't judge a scopes performance by assessing it against only CA. Adam

Just stripped my planetary reduction boxes on the AZ GTI with the aim of improving performance. Anyone else done this? If not then I can post a summary. But don't want to go over old territory if it's a common thing. Adam.

It had better be less than the 492 based cameras or what's the point.

From the lack of consistency between samples recently being reported in the case of the L-extreem at 7nm I would not be confident in becoming an early adopter of a 3nm filter from optolong. The margins of error are very much tighter than for the 7nm. This is even worse as you have to get it correct twice per filter for duel band as opposed to once for a conventional single pass 3nm. Time will tell, from my knowledge of such things it would also be technically difficult to pre-shift the pass band for higher F-ratios due to the amount of shift for OIII and Ha being different even if it can be precisely controlled then it may result in the filter only being optimal over a narrow range of F-ratios. If optolong pull it off it will be a marvelous filter, however the chatter amongst those performing these tests is that Antlia are producing a more consistent product. Adam.

Hubble. Gold and blue.