Pitch Black Skies

Do you think it will make much of a difference in placing the UV/IR filter just in front of the camera sensor versus at the end of the coma corrector? I'm thinking if the coma corrector isn't significantly bending the light, it shouldn't make a huge difference?

I think I'm confusing chromatic aberration with star bloating and halo's, as seen in John's image.

I believe that while chromatic aberration isn't present with a reflector, the colour balance is disrupted if a UV/IR filter isn't used. Add a refractive coma corrector to the mix, and you have a recipe for disrupted colour balance and chromatic aberration. Best to use the UV/IR I think (that is if you can release it). But even better to conduct an experiment and compare the results with and without. That way others will learn, plus you'll have ☮️ of mind. Try to give it a bit of integration time for a more accurate result.

Welcome to SGL, great choice for first scope 👍 RA is for equatorial mounts, you won't need to worry about it. It's worth picking up a Cheshire sightube or collimation cap to ensure you can collimate it. Clear Skies

That is actually a great idea to drill holes. I'm using a bit of tape on the ground at the moment. It won't last very long.

So an EQ6-R any day or night, provided it's in an observatory. I don't have an observatory unfortunately. However the furthest I would ever be carrying it would be just outside the front door of a bungalow. Great that your friend is achieving that accuracy but being a mass produced product I think it could vary from example to example. I'm thinking it would makes sense to pay the extra couple of hundred or so for the higher payload capability.

I've since sold the Meade. It was sturdy but the electronics were old and fragile. I opted for a second hand EQ5 Pro with the intention of progressing to autoguiding thus taking advantage of the ST4 autoguiding port. I have since learning that I can pulse guide with an EQDIR cable. I can tell you that the Meade was a better mount. It's much heavier, beefier and smoother. It uses a bearing on each axis while the EQ5 Pro only uses one on the RA axis. The Dec axis can become very stiff. I have now sold the EQ5 Pro and am mountless. My next mount is either going to be the HEQ5 (Rowan mod) or EQ6-R. There isn't a huge price difference between each of them when the Rowan mod and bearing puller is factored in. The EQ6-R comes with upgraded latitude bolts although a lot of owners seem very unhappy with them. Any thoughts?

Thanks very much mate. If it's not having any major impact I'll live with it for the time being. Now just waiting for another few clear nights.

I had some lights from last week so I chanced calibrating them. Just lights stacked and processed ⬇️ The lights then calibrated and processed the same ⬇️ I noticed those specs too. I have no idea what they are. They look a bit worrying. I can't see any negative impact on the final image when the master flat is integrated though. The camera lens looks pretty clean. I'm thinking it might be the primary mirror.

Luckily DSS has a dropdown for dark flats. I've done a little experimentation. You're right about the bias frames, as is @CCD-Freak who I was chatting with also. Thank you both for your help btw. The bias frames indeed add to the noise. There isn't a significant difference when using darks but there is definitely some data there so best to use them I agree. Flats made the biggest difference for me, and more so when combined with the dark flats. I have found the best result using darks, flats and dark flats (just like both of you recommended). Here is some data I have pulled from a master dark, flat and dark flat. Included is a stretched and unstretched version. MasterBias_Gain100 Stretched.tifMasterBias_Gain100.tifMasterDark_Gain100_30s Stretched.tifMasterDark_Gain100_30s.tifMasterDarkFlat_Gain100_1s Stretched.tifMasterDarkFlat_Gain100_1s.tifMasterFlat_Gain100 Stretched.tifMasterFlat_Gain100.tif

Thanks Martin

Cheers mate, I've just found an option on NINA called flat wizard. It seems pretty good. Going to give that a try now.

Cheers Richard, that's really helpful. I haven't mustered up the courage to venture over Pixinsight yet. I'm using DSS and Startools atm. Coming from a DSLR, I suppose I'm just not used to seeing no dark noise. How do recommend I should take the flats? I only have access to the t-shirt method or a laptop screen with an A4 page.

I went for this exact set up recently. I chose the mini mono as it's highly sensitive and almost weightless. You won't need anything extra for it to come into focus. If weight isn't an issue, the usb 3 colour version is a good shout from @Clarkey. PS, I have been unknowingly using both the EQDIR and the ST4 cable, so thanks for the tip. The one thing I got with mine was an extra 21cm dovetail to mount it on top of the tube rings. It doesn't budge, not sure if that would be the same clamped into the finderscope shoe. This is a great tool from FLO btw to help you make the right decision based on your OTA and main cam.

Can someone recommend what calibration frames I should use with the above camera please? So far I have just made up some darks. I have processed two stacked images (30s exposures, -10°C and at Unity Gain 100). One image is just lights and the other is with lights and 100 darks. I can't see any difference in both of the pictures side by side. Are dark frames needed with this camera? I can upload a stretched dark if someone wants to have a look. I've read somewhere that bias frames are not needed as darks contain both dark noise and read noise. Is that correct and if so, should I not use them? Do I need to subtract bias frames from my flats as they contain read noise or should I just include dark flats?

M45 - 6 minutes M42 - 26 minutes

Something different for a change, a picture of the terminator in daylight. Date - 25th Nov 2021 Time - 10:10 Location - Ireland Phase - 0.71 Waning Gibbous Constellation - Cancer Magnitude - -12.20 Distance - 395659.14 km Diameter 30.20' Camera - Canon 800D Lens - 18-55mm Telescope - 130P-DS Mount - EQ5-Pro Method -One foreground picture at 55mm -One picture of the moon through the telescope -Cropped and edited in PS

Apologies, I mis-read your post. I thought you were referring to the GPU. Once your spacing is rectified, consider upgrading the adaptor with the two thumbscrews to a compression ring with three thumbscrews. It gives a much more even and concentric fit, minimising the chance of tilt in the optical train.

It should be much sharper, mine is. Are you sure you've the GPU? It doesn't change the focal length, thus you would still need to chop the focuser tube, I did. Back focus is 53mm for F4 but F5 can get away with 55mm which is basically just an 11mm t ring attached. How is your imaging train clamped together? Are thumbscrews, compression ring, etc? Edit: It does actually push the focus point out by a little if screwed directly onto the focuser tube.

Can definitely see an improvement with the CC. Without it, it looks like seagulls in the top left corner. Much better corrected in top left with the CC. Without CC ⬇️ With CC ⬇️ This is in a 130P-DS yeah? How long were the exposures and do you know if the options are full collimated. The reason I ask is, I think the pics with the CC should be a little sharper.

I took it for a quick test drive last night to see how it stacks up against my DSLR. Each image is only around 7 minutes integration time each with no calibration frames. Processed in ST. DSLR ⬇️ CMOS ⬇️ -very pleased with the results.

That's odd. What does a single exposure without the CC look like?

Congratulations on your EQ6R! 💪 I have the same setup, albeit riding on an uncertain EQ5. I have opted for the ZWO ASI533 MC-PRO after some digging around. If you can live with the square fov, the 533 has lower read noise (1.0e), higher QE (80% peak), and suffers zero amp glow. Paired with the 130P-DS under OK seeing conditions, it gives an ideal resolution of 1.19"/pixel. https://astronomy.tools/calculators/ccd_suitability Clear Skies 👍

My early Christmas present, thanks to @vallyman

Yeah, it's definitely not something you would want to be rushing. Give yourself plenty of time, or maybe do an hour here and there over a few days. It can be a bit painstaking but I was also going to mention like you said, you have peace of mind. It's also very satisfying to know everything is squared up. It's a good opportunity to get to know your telescope better too, us Newton owners are tinkerers at heart. If my memory serves me correctly I think the chap accidentally broken his secondary mirror in that video I shared. Be super careful 😬😊 Ricochet's advice above is really good, it should really help narrow it down. Be sure to update when you've found the culprit!