This works with broad a red filter on Oag @1400mm with zwo 120mini , When shooting HA with your main imaging cam . Great guide numbers don't mean much if your main cam is effected by seeing ;)
This defiantly works. I mentioned it on cloudy nights about 2 years ago. Did a video too though a lot of people brushed it off because I did not show any numbers. Thanks for confirming it with some numbers. You might want to try the test with an object close to the horizon. That is where I could see more improvement.
Hey Roro! Would you consider doing a follow-up video with a more capable camera? I just received a QHY5III678M as in mono and it comes with an 850nm filter. I haven't had a chance to try it yet as we are suffering from smoke issues but I may try anyway to see if I can guide with a smoky atmosphere. I would update with my results but I only have a mount with encoders so that may not be fair 🙂The QHY5III678M just got released so maybe you can nudge QHY to send you one for testing? Excellent content mate! Clear Skies!
Thanks Ron, I am certainly going to give this a try. I am here in Savannah, GA at nearly sea level and I have to look through a lot of atmosphere. At time, it looks as if I am looking up from the bottom of a pond when the humidity is high, which is just about all the time in the warm months. I will let you know how it works.
Thanks for going to the effort on this subject and creating a video. I'd suggest repeating the testing on a poorer night of seeing where improvements are likely to be greater?
The biggest bump in performance I got in guiding was from multi star guiding. I can’t see that it’s worth getting a filter and setting it all up if the performance gain is only 7%. As you said, “it’s not statistically significant.” This might be worth some consideration for others though.
I agree, multi-star guiding brings a lot to the table whereas this seems to be more subtle once you enable multi-star guiding. I plan to test this further under worse seeing condition to see if it helps at all there, but I think the overall benefit from this will be small.
I gave it a try (MyT mount, Esprit 100ED w/ASI2600MC, WO Z61 as guide camera with a ASI290MM. I noticed (while watching the PHD2 guide star monitor) that the star HFD appeared to more stable and the image the monitor more stable/consistent in size. This was on a dry clear night with a lot of thermal turbulence (Astropheriq rated it as below average seeing for my location). Ancedotal/appearance is that the guide trends were more stable w/less star 'motion' driven corrections. Typically on nights like this I have to slow down/extend the exposure times to prevent PHD2 from chasing 'seeing'. I did not have to do that the two nights I've spent testing it.
I've been guiding in infrared for three months with my qhy 462c with the very same Antlia filter in your video I image in the white zone in the middle of a large city. When I'm using my long focal length setup with an oag to capture small planetary nebulae, I always found that an IR filter is better than an UV-IR cut filter in stabilizing the apparent star movement. The guide rms number doesn't drastically change, but the peaks and spikes in the guide graph does seem to appear less with IR filter on. That difference could have been caused by the wind or just a coincidence, but it works for me anyways.
I noticed similar results. The overall RMS was similar but it seemed to have a smoother graph, less spikes as it went along. I can see how this would help with longer focal lengths.
Thanks for this video. I have been using a 685nm ir pass filter since a few months and it has significantly improved my guiding. I agree, that the added benefit got less since the introduction of multi-star guiding (in my case to the ASIAir). For me, the most important point next to the seeing turned out to be a good polar alignment. Just repeating the PA process a second time from a different RA position already helps me for a significant improvement. Usually, I get between 0.6 and 1 RMS error from my city backyard and my personal best was 0.11 RMS for about an hour and staying below 0.28 RMS that whole night. I did not get that low even in exceptional nights without IR guiding. That was all done using an EdgeHD 8", Off-Axis Guiding, an EQ6-R mount and my trusty old 120mm mini as guiding camera.
Nice experiment, I've tried this a few times using a light pollution filter with zwo asi224mc and OAG, under Bortle 5 sky. It never seemed to make a noticeable difference but next time I'll pay closer attention and try some before/after tests.
LP is not the issue affecting your guiding, it's the wavelength of light that is used to measure the star's position. Longer wavelengths get diffracted less than shorter ones, so the effect of the atmospheric turbulence is reduced. An LP filter still admits the shorter wavelengths, so there will not be an improvement.
@@pompeymonkey3271 I was thinking it might improve contrast which might result in better stars for guiding. I do get what you're saying, makes sense. Thanks
Multi star guiding is by far the most cost-effective and efficient way of limiting HF atmospheric disturbance without the need for filters. On a well set up rig, I would confidently predict a 25% improvement of overall guiding accuracy. Interestingly, I have run a few tests recently and found that having almost laughably out of focus stars has given me incredible levels of guiding accuracy when using multi-star guiding often averaging under .3 arc seconds on an EQ6R pro. Go figure. The downside being if, like me, you use the guide scope as a plate solve setup for polar aligning, focus has to be within a sensible range or the solve will fail... There is "scope" ahem, for another really good video here should you be interested. As a last comment if I may, the guide scope here is not really optimal on such a long focal length main OTA either....
Did you keep the exposure time the same for each run? The filter will reduce the total amount of photons, which usually means lengthening the exposure to compensate. A longer exposure will smooth/blur out the turbulence, to a certain extent.
I kept the exposure time the same for both runs to keep it fair. This did reduce the SNR of the filtered run but felt that better than giving it more exposure time.
Wait, I'm confused... You referred to your guide camera several times, as the 294 monochrome mini. That very much piqued my interest, so I went looking for such a camera. The sensitivity and FoV would be absolutely amazing, but at the same time, very much overkill for a simple guide camera. Unfortunately, there doesn't appear to be a 294mm mini. Would it be correct to assume you're using the 290mm mini instead?
This works with broad a red filter on Oag @1400mm with zwo 120mini , When shooting HA with your main imaging cam . Great guide numbers don't mean much if your main cam is effected by seeing ;)
Great point!!
The second video about this that makes incredible sense..to me
This defiantly works. I mentioned it on cloudy nights about 2 years ago. Did a video too though a lot of people brushed it off because I did not show any numbers. Thanks for confirming it with some numbers.
You might want to try the test with an object close to the horizon. That is where I could see more improvement.
Yes good idea…will try tonight.
also another good test would be to try with and without the filter with Multi-star guiding turned off
Hey Roro! Would you consider doing a follow-up video with a more capable camera? I just received a QHY5III678M as in mono and it comes with an 850nm filter. I haven't had a chance to try it yet as we are suffering from smoke issues but I may try anyway to see if I can guide with a smoky atmosphere. I would update with my results but I only have a mount with encoders so that may not be fair 🙂The QHY5III678M just got released so maybe you can nudge QHY to send you one for testing? Excellent content mate! Clear Skies!
I use broad red and IR 642 filters in my setups. I noticed up to 20% improvement in RMS. Multi-star guiding gives similar or better results.
EXCELLENT video. Solid information with easy to understand examples.
Thanks!
Thanks Ron,
I am certainly going to give this a try. I am here in Savannah, GA at nearly sea level and I have to look through a lot of atmosphere. At time, it looks as if I am looking up from the bottom of a pond when the humidity is high, which is just about all the time in the warm months. I will let you know how it works.
Thanks for going to the effort on this subject and creating a video. I'd suggest repeating the testing on a poorer night of seeing where improvements are likely to be greater?
The biggest bump in performance I got in guiding was from multi star guiding. I can’t see that it’s worth getting a filter and setting it all up if the performance gain is only 7%. As you said, “it’s not statistically significant.” This might be worth some consideration for others though.
I agree, multi-star guiding brings a lot to the table whereas this seems to be more subtle once you enable multi-star guiding. I plan to test this further under worse seeing condition to see if it helps at all there, but I think the overall benefit from this will be small.
@@AstroWithRoRo I’d be interested in hearing any follow up resulting from your research.
Interesting video. I may have to try that
I gave it a try (MyT mount, Esprit 100ED w/ASI2600MC, WO Z61 as guide camera with a ASI290MM. I noticed (while watching the PHD2 guide star monitor) that the star HFD appeared to more stable and the image the monitor more stable/consistent in size. This was on a dry clear night with a lot of thermal turbulence (Astropheriq rated it as below average seeing for my location). Ancedotal/appearance is that the guide trends were more stable w/less star 'motion' driven corrections. Typically on nights like this I have to slow down/extend the exposure times to prevent PHD2 from chasing 'seeing'. I did not have to do that the two nights I've spent testing it.
I've been guiding in infrared for three months with my qhy 462c with the very same Antlia filter in your video
I image in the white zone in the middle of a large city.
When I'm using my long focal length setup with an oag to capture small planetary nebulae, I always found that an IR filter is better than an UV-IR cut filter in stabilizing the apparent star movement. The guide rms number doesn't drastically change, but the peaks and spikes in the guide graph does seem to appear less with IR filter on.
That difference could have been caused by the wind or just a coincidence, but it works for me anyways.
I noticed similar results. The overall RMS was similar but it seemed to have a smoother graph, less spikes as it went along. I can see how this would help with longer focal lengths.
Thanks for this video. I have been using a 685nm ir pass filter since a few months and it has significantly improved my guiding. I agree, that the added benefit got less since the introduction of multi-star guiding (in my case to the ASIAir). For me, the most important point next to the seeing turned out to be a good polar alignment. Just repeating the PA process a second time from a different RA position already helps me for a significant improvement. Usually, I get between 0.6 and 1 RMS error from my city backyard and my personal best was 0.11 RMS for about an hour and staying below 0.28 RMS that whole night. I did not get that low even in exceptional nights without IR guiding. That was all done using an EdgeHD 8", Off-Axis Guiding, an EQ6-R mount and my trusty old 120mm mini as guiding camera.
Agreedm a solid PA is one of the most important things you can do to help with good guiding. That's a very good RMS for thr EQ6-R mount too!
When i tested first time my zwo 120MM-s camera without an IR cut filter i had bloated stars
Nice experiment, I've tried this a few times using a light pollution filter with zwo asi224mc and OAG, under Bortle 5 sky. It never seemed to make a noticeable difference but next time I'll pay closer attention and try some before/after tests.
LP is not the issue affecting your guiding, it's the wavelength of light that is used to measure the star's position. Longer wavelengths get diffracted less than shorter ones, so the effect of the atmospheric turbulence is reduced.
An LP filter still admits the shorter wavelengths, so there will not be an improvement.
@@pompeymonkey3271 I was thinking it might improve contrast which might result in better stars for guiding. I do get what you're saying, makes sense. Thanks
Twinkle, twinkle little star, hopping around like you are, it's atmospheric turbulence that makes you so, is infrared the way to go?
Love this! 😄
Multi star guiding is by far the most cost-effective and efficient way of limiting HF atmospheric disturbance without the need for filters. On a well set up rig, I would confidently predict a 25% improvement of overall guiding accuracy. Interestingly, I have run a few tests recently and found that having almost laughably out of focus stars has given me incredible levels of guiding accuracy when using multi-star guiding often averaging under .3 arc seconds on an EQ6R pro. Go figure. The downside being if, like me, you use the guide scope as a plate solve setup for polar aligning, focus has to be within a sensible range or the solve will fail... There is "scope" ahem, for another really good video here should you be interested. As a last comment if I may, the guide scope here is not really optimal on such a long focal length main OTA either....
Did you keep the exposure time the same for each run? The filter will reduce the total amount of photons, which usually means lengthening the exposure to compensate. A longer exposure will smooth/blur out the turbulence, to a certain extent.
I kept the exposure time the same for both runs to keep it fair. This did reduce the SNR of the filtered run but felt that better than giving it more exposure time.
I have a 462C, might try the IR guiding as the camera is basically mono in the IR range :)
Is 120mm FL enough to guide that big Mak
I’d love to hear your results if you give this a try. The 462 is perfect for this with its great & even IR sensitivity.
Hi Everyone. I had a big improvement on guiding since i start to use Metaguide software. Have you try that? Thank you.
Seems like the idea you are trying to test is best tested on a night with worse seeing... so retest please
Wait, I'm confused... You referred to your guide camera several times, as the 294 monochrome mini. That very much piqued my interest, so I went looking for such a camera. The sensitivity and FoV would be absolutely amazing, but at the same time, very much overkill for a simple guide camera. Unfortunately, there doesn't appear to be a 294mm mini. Would it be correct to assume you're using the 290mm mini instead?
Yes sorry the 290MM Mini is the camera I have here.