Adam J

The first thing that annoyed me with this mount was that its not possible to put the polar scope cover in place if you actually have batteries in the holders, anyone else noticed that? But having just had to remove the cover to tune my RA worm mesh I can tell you that its one of the worst things I have ever had to deal with, and I am well versed in activities such as astro modifying DSLRs, tuning the AZ GTI and other mounts. Its a mine field of epic proportions and makes me wonder what they were thinking. The mount looks well made and well designed from the outside but once you scratch the surface you realise the number of corners cut to make it to a cost. SA actually mounted the Main Board on the back of the cover that you need to remove to access the worm gear assembly. This is bad because its not possible to see that the main board is located in such a way until you start trying to pull it off! WARNING: DO NOT TRY TO REMOVE THE COVER WITHOUT FIRST REMOVING THE MAIN BOARD FROM THE INSIDE FACE! If you do then you will likely pull connectors out all over the place and potentially damage the board as in their rush to save every penny SW have not made the cables just 3cm longer to allow you to fully remove the cover before having to unscrew the board. As such getting it off is almost impossible, but that is nothing in comparison to putting it back on again ill warn you. Even worse you cant perform common maintenance such as refreshing the lubrication to the RA worm without having to go through this. The second thing that annoys me is that they have designed the set screw that determines the amount of pressure placed on the spring mounted RA worm in such a way that is is almost inevitable that its going to loosen off over time (the reason for having to open it in the first place). The ring that it threads into is able to rotate relative to the spur and there is sufficient friction between the two such that it will wiggle the screw from side to side every time the direction of movement of the mount is changed and it comes loose as a result. I have now added purple lock tight to mine to prevent it from doing this again others have used PTFE tape I may yet have to go back and do that if its not sufficient. The next thing is the use of specialist nuts...who has heard of a pig nose nut? Well you will need a specialist tool to undo it so best find out, if you find yourself having to do this. If you have heard of one you will know you need a circlip spanner to undo one. Not a big deal right....well it is a big deal as this one has 1.5mm holes in it and you just try finding a tool with 1.5mm prongs. In short this thing makes working on the AZ GTI look easy by comparison and I do not recommend that the average user attempts to tune the mount themselves as things are likely to go down hill very fast. All was ok and its back together and working fine now, but if I had known I would have thought twice about it. Some general advice to Skywatcher, don't attach things to covers.....people might actually want to take them off. Even if you do then allow for a little slack in the cables. YOU HAVE BEEN WARNED. Adam J

Well it makes it easier to position your eye, but mainly the image will be brighter due to lower magnification. On a 32mm the eye relief will be fine for glasses. Adam

I would think the 32mm 52 degree astro essential would give a similar fov as the 25mm 60 degree BSG. Also with a larger exit pupil in the 32mm.

Just finished putting together a observing rig from bits I had laying about unused with a few new bits. I got a Skymax 102 from the classifieds. I got a new SV191 7.2-21.6mm zoom. A TS 2 inch visual back from RVO because the 1.25 inch diagonal looked rubbish and I have a 2 inch dielectric that came with my Esprit that I have used exclusively for imaging so the diagonal has never seen use. I got a adapter from FLO to allow me to fit the AZ GTI to the tripod from my AZEQ6 Pro. probably going to switch the finder for the Esprit 50mm finder too. Hoping for some fun with my 5yo looking at the moon and planets. I could have gotten this new for the same money spent: https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-skymax-102s-az-pronto.html But I think this was a better option as the AZ GTI and 2inch tripod is ultra stable, the packaged version of the 102 can't be collimated and finally the two packaged eyepieces are plastic rubbish. Adam

Not sure if that was a full on recommendation but I got one for the Skymax 102 grab and go scope I intend to use with my son for lunar mainly. It was either that or a couple of Plossls so high field of view fixed eyepieces were not really a contender. Adam

I own one but have never used the polar scope lol. I align with Sharpcap or NINA via the guide scope. The most important thing is that if you center on Polaris and then rotate the RA 90 degrees is the cross still on Polaris? If so great, if not you will want to adjust it. If it's good just use a mobile ap to find the hour angle of Polaris and rotate the polar scope such that 0 is now to the top. adjust polar alignment and then return the RA axis to the home position. This assumes that I correctly remember that the polar scope rotates with the RA on the GTI.... Adam

So this one: https://www.amazon.co.uk/Svbony-Telescope-7-2-21-6mm-Astronomical-Accessories/dp/B097SDPWJ6/ref=sr_1_1?keywords=7.2-21.6+1.25&qid=1683733683&sr=8-1 is the one you like.

By newer 7,2-21.6 do you mean there are two versions of th 7.2-21.6 or that the 7.2-21.6 is newer than the 9-27. If the former how do you tell new from old. Adam

That was my guess too. Hence only attached at one end.

It depends, it would be hard for another member to test. But you could imagine that a safety feature would be to not allow the tec to power up unless the fan sensor indicated rotation. So if it's a three or four pin fan there is a good chance this is the case. If it's a two pin fan then something else may be going on. It's also possible that the tec has been damaged by the fan failure or that it's a power supply issue and nothing to do with the fan. If it's not in warrenty then I would investigate by removing the back plate.

Its more specific to any fan ever made lol Big PC fans spin slow these days due to the lard diameter, the smaller fans need to spin faster to move any significant amount of air so still tend to fail more often. Adam

Almost certainly a fan failure, happens quite often, take the back plate off, note the fan model and order a replacement. Adam

Ignore, double posted.

I have to disagree, the Rayleigh limit for a 50mm aperture is 2.7um. So you wont get 2.2 arc seconds per pixel even if that is the raw sampling. In terms of resampling you end up at 5.8um pixels in 2x2 and that is actually going to leave you under sampled so its not really an option and you are better off with the 533 at 3.13um per pixels. At longer focal lengths and apertures the 585 may well be a superior sensor for galaxy imaging. The issue with putting it on a wide field scope is that you would be putting a tiny little sensor on a wide short focal length scope just wont make use of the large flat field and makes very little sense. You would be better off with a larger sensor and a longer focal length then binning it as you would have a faster system with the same FOV. Actually such a sensor is avaliable https://www.firstlightoptics.com/zwo-cameras/zwo-asi-482mc-usb-30-colour-camera.html You can see the effect the binning on the form of a quad bayer matrix has had on the read noise. (Same sensor as the slightly older 485 but in quad baryer to get 5.8um pixels). Adam

Sensitivity is made of of three factors: 1) Quantum Efficiency (QE) @ SII 2) Noise (e-) 3) Pixel Area (P) Lets forget the effect of cooling an assume we are doing short exposures <60 seconds so that cooling is not a big factor. We will set gain so that we are left with at least 10 stops of dynamic range in each case (so gain = 300) In that case: S = (QE * P) / e- For the 533: QE = 0.8 * 0.75 (red) = 0.6 e- = 1.2 P = 3.75^2 = 14.06 So S = 7.03 For the 585: QE = 0.91 * 0.76 (red) = 0.69 e- = 1.1 P = 2.9^2 = 8.41 So S = 5.28 S (533) / S (585) = 1.33 So a 33% higher sensitivity for the 533 in comparison to the 585 at 672nm (SII). Essentially you are forgetting the effect of larger pixels on sensitivity. Adam

So I just did the calculation for this and got the 533 as being 30% more sensitive than the 585 at SII wavelengths, SII being the longest wavelength of real interest for the stated application of DSO imaging. Adam

Consider a mono 533, you will not regret it. You can build up filters over time. Adam

The 533 is worth it as an upgrade twice the sensor area and larger pixels makes it more sensitive and with a wider FOV, it is usable over a large range of focal lengths. The 294mc is a tricky camera to calibrate The 2600 is in a totally different price league. Adam

1st one for me the second has had the oiii pushed to the point the some Ha is starting to look blue and forced.

Check your filters are rotating to the correct position.

The best way would be to remove the Ha from the signal and just look at the OIII. Adam

Honestly with the small pixel camera my feeling is that you will want to get a triplet as a minimim and if it was me a quad like this: https://www.firstlightoptics.com/askar-telescopes/askar-fra300-60mm-f5-petzval-astrograph.html The reason for that being that the doublet is not likely to fully exploit the small pixels of your 183mc. If you go with the linked scope you will be imaging at F5 (better as your at a disadvantage in terms of SNR with the small pixels in any case) and the spot diagram for that scope is really excerlent. Adam

Can't find the edt-f model at 70mm on their website. Perhaps a link would help. Adam

Part of this hobby is knowing when to stop processing.....but what the heck one last intense processing focusing on the core and some fun with colour!

You can edit posts by pressing the three dots to the top right of the original. Adam