Hi James, was there a Part 2? Just wondering how, a year later, you're getting on with this camera & Bin 1? Are you still using it, still consider it worthwhile even with the file sizes etc, any extra considerations someone looking at this camera should consider? Thanks!
Hi James, I just came across your video, Ooh my word, I throughly enjoyed it, I have watched hundreds of videos and yours have answered so many questions, I know it’s been 3 years, but it’s still making A impact I’m in Melbourne Australia, Thanks James
Excellent, well put together video, thanks! You have my subscription! Personally If I had to choose just ONE Telescope, I would pick my 200/1000 Newtonian Reflector. It can do almost anything, imaging wise. It also has the best "$/mm of aperture ratio". For reference I own 66/400 ED Refractor, 200/1000 Newt. reflector, 203/1624 Ritchey Cretien, and various other Achromatic refractors that I don't use anymore. I'm 17 months into Astrophotography and 9 years doing visual Astro. Liverpool, England. Bortle 7.
It seems after 2 nights of usage at full power, it destroyed my corrector plate.. my stars now look elongated without even switching it on... Is there a way to revert that back?
Hmm. I’ve never heard of the high heat setting actually permanently damaging the corrector. I used full power for many nights until, I cut things back. No permanent damage in my case. You should verify if there is not another cause. First, take some very short exposure (like 2 seconds) images with the fan off and then with the fan on. If the correct is in fact deformed, the stars will be elongated with the fan off. If they are elongated when the fan is on, then you have fan vibration problem. The very short exposure will eliminate guiding as the source. If you’re still getting elongated stars, check collimation. Good luck!
Very nice video - thanks. One major thing that can mess you up with the OAG is that, depending on your scope type, the actual image orientation of stars that you see in PHD2 is either inverted or mirrored when compared to the main scope image. It would be wonderful if PHD2 had an option to flip / invert the image - it would make life so much easier at 1:00 in the morning.
The heater ring can cause pinched optics. I use my C8 Edge for visual use only and so I do a quick check of collimation with each observing session. After purchasing a dew heater ring and the Celestron controller, I started to notice deterioration of the views after an hour or so. Rechecking the collimation showed clear signs of pinched optics. The diffraction rings took on an hexagonal shape instead of the concentric rings that were present at the start of the observation session. Turning off the power to the heater ring resulted in a return to perfectly concentric diffraction rings 10 minutes after the power to the ring was turned off. I’ll have to fiddle with the control settings to reduce the power to a level that prevents dew formation but doesn’t expand the corrector plate enough to mechanically stress the corrector.
We know how the focal length can be modified. We know the secondary mirror is playing a variable focal multiplier ( p'/p). A tiny difference betwwen the 2 mirrors has a huge impact at the focus . It is about microns . With Oslo simulation 2 microns difference between the 2 mirrors move the focus plan to 124 microns at the back focus at 2032mm Focal lenght ( can be a no problem if this expansion is in the tolerance of the focus ) . But this 2 micons can be worse if this done by the tilt on the primary mirror because the rotation on the primary is converted in linear translation in the focal plane for all the stars . This tillt problem is resolved with the Rasa using a big linear bearing. We learn with Google that the play in the lienar motion of the primary can be between 60 to 120 microns !) For the SCT the ideal solution is to block the optics once the focus is made. To help Celestron has installed (for the last SCT) lockers with tiny rods without no precision to guide them inside the optical tolerance required. In fact any SCT should be modified for atrophotography purpose. this it is not easy when you have never open a SCT before. Too scarry to damage optic.... But their are solutions - you can install a system to clamp the primarry mirror. ( 3 off brakes shoes at 120 deg at the edge of the mirror - you can install or replace with 3 off strong rods at the back of the telescope, guided with 1 1/4 lenght linear bearings , and 3 collets ER type, for clamping axially the rods once the focusis done . - you can block with 4 plastic screws the primary mirror in an specfic position like for the Schmidt blade) and to install an Ascom focuser on the secondary mirror for focusing ( Optec Fast optic dream solution) - For Fastar compatible SCT, to modify the secondary mirror holder in order to use a spacer ring calculated to translate de secondary mirror for specific reducer or barlow focal length , and in order to finalise the focus, to install a Crayford focuser at the back of the SCT. - To make holes il the tube in order to lock the aluminium tube sliding with the primary mirror . -for the one having a workshop, to rebuit the slinding tube with tiny bearings at the both ends maintain by the elasticity of the metal . This is the mechanical solution for Theodolite in the past.
I really love your content. Your videos on the Celestron dew rings convinced me to stick with my dew straps. Thanks for taking the time to collect all this data and share it with us in such an informative way. I still wasn't able to tell from your testing if the strap should be on the dew shield, heating the air in front of the glass, or on the tube heating the air in the tube. Thanks again for all the work you do.
Hi Ted. Thanks for watching. I’ve heard different thoughts on that. I put mine around the foam dew shield just in front of the corrector plate so that it can heat the air in front of the corrector plate. I just don’t see how the (seemingly) small amount of heat these dew straps generate can heat the OTA tube and the air behind the corrector plate. I am planning to get a second dew strap and place it adjacent to the one I have. One thing about that stupid Celestron dew ring is that it definitely kills dew. It’s just the other stuff it does that’s the problem. Good luck!
Hi James, I'm trying to get this to work from the southern hemisphere but I just can't get it to generate any data (looks like it is locked up). Just trying by putting the coords for Melbourne Australia in (-38, 145.2) and limiting it to 100 catalog entries, and it doesnt seem to do anything. Looked at the Python, but that doesnt seem to work either, like that isnt the code you built the .exe from. Note that it works fine with your defaults, and I am using your horizon file
Really useful work here. We need all the help we can get to avoid the dreaded “No guide-star found” during critical capture time. Setting up the tiny guide camera sensor to identify the center is ingenious. Thank you.
Thanks, Ted! Been a while since I made that video and have added a William Optics GT81 (385 mm focal length) to the lineup and I still stand by my conclusions: the SCT is the most versatile year-around scope, but what a beating… Enjoy the night!
The horse head / Flame was my first target. I go back to it every fall and winter as a touchstone to see how my equipment is doing and test new techniques. The one thing I always use to judge my image is the little companion star next to Alnitak. If it stands out distinctly, then I consider that a better indication of a good image. If Alnitak "eats" it up, then I think the image could be better. I can just start seeing the little star in your Antlia filter image. Not in the zwo filter image. - While i am sticking with osc for now, I am considering retrieving some HSO data by using a couple of duo band filters (Ha/Olll and Sll/Olll) to collect these narrow bands. Maybe the Altair filter set, either the 4nm or 6nm, still trying to find out if these filters create halos. Asi2600 mc and 152ed doublet F-8 (uder construction a 140mm triplet F6.5 - purchased lens cell, building the rest).
Yep. The Horse head kicked my butt the first time. Nice observation about the small star next to Alnitak! Been so distracted by the stupid halos. Still room for much improvement for me on this target, including adding significant RGB.
You can get by with a shortened dew shield. I cut mine down to project beyond the OTA by about 3”-4”. Maybe could try with no dew shield but you may have to dial up the power on the dew ring. Some people, including myself, see star bloating and streaks on some bright stars at high power.
I guess that after blur xt deconvolution star size in pixel goes down introducing undersampling. This makes quantization noise on eccentricity calculation spreading results. Try again by drizzling by 2 before blurr xt
That’s a tough question because it depends upon seeing (and guiding) and aperture of the scope you’re using. You should get smaller HFR for larger diameter aperture and better seeing. I have NINA write the FWHM into the file name for use later, but not the HFR.
Yes, it’s still my source for taking flats. I like it. Expensive, but works well. I don’t connect it to NINA either. I just set the power to 75% and take my flats. I have. “FLAT” sequence with exposure times set for each filter. I don’t mess around with the FLAT exposure optimization thing in NINA.
I am having this issue where i follow your instructions and when it comes to the linear fit using b2 as the reference image, it only applies for G2 but none of the other two. same with the b1 only applies to the g1 but not g2 or b2 like shown in your video. If i continue to the pixel math step, i get an error telling me that it couldnt execute because there is no active image window. Do you have any clue what is going wrong with mine?
Hmm. Not sure how you’re applying it. Load the reference file name into LinearFit, the drag and drop the triangle icon onto each of the other 3 images. Should work ok. Let me know if it isn’t and give me more detail about how you’re using it and I’ll try to help. Good luck!
Hi James, bit of an older video but still relevant today. I’ve been experiencing a lot of what you’ve covered here. I have a very high precision electronic focuser, on the order of 7nm steps. I’ve just recently fitted it to an EdgeHD 8 and my step size and overshoot numbers have been very high with HFR being very inconsistent. I’m looking forward to working with some of the additional settings you’ve outlined here. Cheers! Doug
Fascinating! I don't have your mathematics brain, but I came to the same conclusion and back focus as you have through trial and error. Interestingly though I long ago gave up with the Celestron reducer and my results apply to the starizona 0.63x reducer. At the starizona recommended back focus of 95mm I was getting the same star shapes as you do. After many lost nights fiddling with spacers I eventually found that I got pretty much perfect round stars at all edges by removing every spacer I possibly could and I ended up at around 85mm. A full 10mm less than it 'should' be. So maybe this is more of a c9.25 issue than a reducer issue? I feel fully vindicated now anyway after your video! Even though I'm happy with my results, I've been assuming I'm doing something wrong by settling on such a significantly different back focus than the 95mm it should be!
Thanks for watching! I’ve heard a lot of people saying great things about the Starizona reducer/corrector, so you should do very well wit( it. Like you say, the C9.25 might have a good bit to do with the back focus issues people encounter.
Interesting video James! I noticed on my Antlia triband I end up having some kind of blueish colour in the core of my pictures like a circle background. You didn’t face any of that?
Hey Mike, No. Nothing like that. I’ve been very pleased with the TriBand. Try taking some FLATs with and without the filter and then break the color images into RGB components to see if you can tell where the blue is coming from.
I’m getting pretty good and consistent guiding with the EQ6-R. Below 0.53 arc-sec 80% of the time ( see ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1NcPYaH65wg.htmlsi=42lJsUmRe0yUf6op). Doesn’t really matter if I have the Redcat or the C9.25 on the mount. Given typical seeing for my area, the guiding has been as good as can be expected. Thanks for watching!
Have you ever used the starizona .63 focal reducer/flattener? I have a very similar telescope, oag and camera configuration, and would hope their distance of 90.3 mm for the back focal distance would be more accurate than the celestron reducer. Thanks for the detailed video, it is much appreciated!
No, I don’t have the Starizona reducer/corrector, but I’ve heard very good things about it. Just not sure I’m interested in a another $400 to $500 investment in this scope. The perfect is the enemy of the Good…. I may just settle for “good” in this case. Thanks for watching.
I guess my explorer scientific 127mm f/7.5 with their 0.7x reducer/flattener would make a nice combination at 666mm focal length. Without focal reducer I have 952mm.
The 127mm focal length is a good scope. Without the reducer, you can get good pics of small galaxies and not have to worry about the non-flat field in the corners. For galaxy clusters and some nebulae, you can use the focal reducer/corrector and get good star shapes out to the corners.
Hi James I have a similar setup with my Celestron SCT 9.25 scope and Celestron OAG guider with ASi174mm camera. Always get a lot of helpfull information for checking my setup or tweaking it. I had watched your youtube videos of creating a FOV indicator in Stellarium for the OAG . "Using stellarium "markers" to setup an off axis guider. " Changes to Off-axis guider view settings in stellarium v23" One thing I noticed, you seem to have changed your Mirror distance from the bottom of the OAG housing to the bottom of the prism. It went from 47mm to 45.5mm. Did you find something in your analysis of the setup that lead to the change? I run with 2 different cameras on my SCT. A ASI2400MC pro , full frame and a ASI2600MC pro APC imager. Right now I have the prism set at 49 mm from bottom of the OAG housing to (I think) prevent too much intrusion into the Full frame imager FOV. Does this seem reasonable to you? Thanks for any help on this. Always enjoy your videos. Take care Steve
Haha. I see what you’re trying to do! You want me to go back and watch all of my videos. No way! I’ll try to go from memory rather than endure the torture. There are a coup,e do things going on… 1. Stellarium v23 - they changed the CCD/prism distance from (before v23) center of optical axis to BOTTOM of prism to (v23 and higher) center of optical axis to CENTER of prism. So that’s a 6.25 mm (for the Celestron 12.5mm prism) change just to make the OAG image the same from v22 to v23. 2. I also have a video (pre v23, I think) where I define an OAG “bull’s eye” and use Stellarium “markers” to place the main scope at a RA/DEC so that the guide star is in the bull’s eye. If it’s off, I make changes to the CCD/prism distance in the Stellarium Oculars settings so that the star will be in the center of the bull’s eye. That may be the source of one change you’ve seen. 3. And I’ve also changes to the physical distance from the center of the scope axis to the center of the prism to try and get more round guide stars (reduce the distance) without suffering too much of an OAG stalk shadow (increase the distance). So those are the things I’ve been exploring in the various videos. If your star patterns as seen in PHD2 look like Stellarium’s OAG view AND you’re not plagued with a significant OAG stalk shadow, then no need for any changes! Thank for watching, Steve….so I do t have to
@@Aero19612 hi James I wasn’t sure if you paid attention to the peanut gallery commenting on your postings. I always seem to find something of interest in your posting s. Probably because my setup matches yours , such good taste we have. Ha I obviously fell behind on watching your videos. Was sidetracked getting ready for eclipse. Sigh . Traveled to one of the mostly cloudy areas. Thanks for your postings and in depth explanations. Take care. Steve
@@Aero19612 James. You always do a great job. I look forward to your videos since they are detailed and well presented. As a retired ME design engineer (robotics & machine vision) you keep my attention with the details. Thanks, take care
Great! Some great tools in PixInsight for this.not sure how good they work for planetary though. Imaging the Moon is great for learning, especially when it’s near full. Have fun!
I am in Bortle 7 and have been deciding for many months if I should with OSC+ narrow band filter or mono camera. Can I get the same results in using OSC from bottle 7? What should I go with?
Hi James. What is the blue part on your guide camera and what is it's purpose? I've been using my Celestron OAG on my C8 for a few months now. I noticed during focus adjustment the helical focuser wasn't smooth throughout the focus range. It would be smooth then resistance was felt. When I removed the guide camera (ASI174MM) the helical focuser was smooth throughout the range. I notice the OAG guide camera barrel is a bit oversized for the guide camera. The two locking screws cause the guide came to push against the focuser tube that moves up and down. I guess it's not a big issue if you can start the guide camera near the backfocus point then only have to move a couple of millimeters to tune in the focus. I do wonder if the locking screws can cause the guide camera to tilt a little that might affect focus so that one part of the sensor is in focus and another isn't. I see what appears to me to be some stars in focus an others out of focus in PHD2. I have a ZWO helical focuser that can screw onto the top of the Celestron OAG focuser. The ZWO users two screws but a brass ring is used to clamp onto the guide camera body. The focuser is smooth throughout its travel range. It works with the Celestron focal reducer and its 105mm back focus but not with the Starizona focal reducer's 90.3 mm back focus. You can't get the guide camera sensor close enough to 90.3mm, 96mm.
That blue ring as a par focal ring from Farpoint (bought on Amazon): Parfocal Ring for 1.25" Eyepieces, FP500 I don't think the two set screws will cause rotation since one screw pushed the camera against the helical focuser wall and the other set screw will push the camera against the focuser wall 90 deg away. That said, there can be some issues. I've had decent luck with the Celestron OAG. I have a later video that looks into the backfocus for the Celestron reducer. I got elongated stars at 105 mm and better results at shorter back focus (~85 mm). Thanks for watching!
Hey Ron. I ask myself that same question all of the time, haha. Yeah, been slammed with work so not much free time to make videos. I've got a few in mind.
Having exactly similar star spikes on my RASA 8" with installed dew heater ring; how does Celestron not know of such an issue and continue to sell this product that causes such optical issues?
Yeah. I see this kind of thing over and over with them. I think they have an idea and push it to manufacturing and let the customer identify the design deficiencies. Oh well. Thanks for watching!
Hi James, so its two year on from when you posted this. Is the issue with the home position and GSS resolved yet? If I have to remember to set it every time, I'm bound to forget one day. If it is, I'll give GSS a go.
Hello! Excellent video. Who can help me? I have a Meade LX200 10" and I have the Celestron 0.63X reducer. Could any of you give me the adapters, Drawer Filter and OAG that work best for me to achieve focus. Thank you, I await your responses.
Hi Alejandro, I don’t anything about the Mead equipment. If you are using the same focal reducer as I have, I decided that a back focus around 85 mm works (check with my video to be sure). As far as what filter drawer, etc that works “best”, I’m not sure. You might that the Large OAG from ZWO doesn’t take up as much back focus as the Celestron OAG. Just add up the numbers, like in the video, to see what adapter lengths you need to make up the difference. Good luck!
