Hi everyone - is anybody using an L-Ultimate while guiding? I'd seen at least one anecdotal report elsewhere that this works fine with the 2600MC Duo's guide chip, but I'm cautious since it's just 3nm bandpass, so very little light reaching the guiding chip. I know the L-eXtreme will work fine at 7nm, but I'm hesitant given the halo risk. I'd really appreciate any real world feedback! I'm looking to use this with my Zenithstar 61 (f/5.9 360mm focal length).
Guiding with Optolong L-Ultimate?
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I used this combination in a bortles 1 down in new mexico and had zero guiding issues. See my image of the elephants trunk for reference.
Rokinon 135 ASI2600MC pro Duo and Optolong L-ultimate no issues
Hi ! I often use the Duo guiding with the L-Ultimate and never had issues with it. It does require a longer guide exposure though (2s is fine with a f/4.5 scope)
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What scope? Aperture? F ratio? And mount?
in general you need guide stars and light to reach the guide chip. It works on my RASA at f/2 with 0.5sec guide exposures for my harmonic mount.
You may struggle with a harmonic mount that needs 0.5s-1s exposures if your system is slower. If the mount is better and doesn’t need frequent guide pulses (say 3-5s) you could get away with f/5-f/7.
i have no faith in it performing at f/10+
in general you need guide stars and light to reach the guide chip. It works on my RASA at f/2 with 0.5sec guide exposures for my harmonic mount.
You may struggle with a harmonic mount that needs 0.5s-1s exposures if your system is slower. If the mount is better and doesn’t need frequent guide pulses (say 3-5s) you could get away with f/5-f/7.
i have no faith in it performing at f/10+
I use the L-Ultimate with my WO FLT91 at 540mm and f5.9. It runs well. I do need to increase the gain up a lot to maintain 1 second exposures but I’ve produced plenty of fine images with it. My mount is the AM5
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
I use the L-Ultimate and 2600MC DUO on my Redcat 71 and it guides just as well as it did when I was using the L-eXtreme. I use a eq6-r pro mount and can consistently guide with a total RMS error of between 0.5 and 0.8.
Like you, I was a little worried about guiding with the DUO based on comments that I encountered online, but based on my experience all the concern about guiding through narrowband filters is completely overblown. See my Heart and Soul nebulae pics for examples.
The L-Ultimate is a much better filter than the L-eXtreme and you'll be glad you made the switch!
Like you, I was a little worried about guiding with the DUO based on comments that I encountered online, but based on my experience all the concern about guiding through narrowband filters is completely overblown. See my Heart and Soul nebulae pics for examples.
The L-Ultimate is a much better filter than the L-eXtreme and you'll be glad you made the switch!
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Wow, thanks everyone for all the feedback, this is very helpful. Now I feel confident giving the L-Ultimate a try myself. Hopefully this thread will help others as well. I struggled to find much information elsewhere. I'm using an AM3. With no filter I'm getting 0.4-0.6 total RMS error at 1-2s exposures with low gain. Sounds like I'll just need to increase the gain to use with the filter.
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Tony Gondola:
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
You use an IR pass and the L-Ultimate with the 2600 DUO? The LUltimate would just cut that out.
I guess I’m the exception here. I’ve been having trouble using an L-extreme on an RC8 reduced to F6. But that’s during a 3/4 moon and the reducer that is creating some vignetting. Seeing hasn’t been very good either. I switched to a Tri-band and issue went away.
John Rush:Tony Gondola:
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
You use an IR pass and the L-Ultimate with the 2600 DUO? The LUltimate would just cut that out.
No, IR pass only.
Tony Gondola:John Rush:Tony Gondola:
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
You use an IR pass and the L-Ultimate with the 2600 DUO? The LUltimate would just cut that out.
No, IR pass only.
I guess i’m confused then, the question is about the L-Ultimate with 2600 Duo.
I have an Askar FRA300 (F5), I always switch to a separate guider when using the L-Ultimate with the 2600 DUO. Imaging time is very limited, so I rather don’t experiment.
John Rush:Tony Gondola:John Rush:Tony Gondola:
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
You use an IR pass and the L-Ultimate with the 2600 DUO? The LUltimate would just cut that out.
No, IR pass only.
I guess i’m confused then, the question is about the L-Ultimate with 2600 Duo.
Don't confused John, just providing a real world data point that the original poster might find relevant. A data point if you will.
Tony Gondola:John Rush:Tony Gondola:John Rush:Tony Gondola:
I guide with an IR pass filter that cuts everything out above 685nm. With an 80mm F/5 guide scope I've never had a problem. My guide exposures are 2" but that's just to smooth the seeing not because of S/N.
You use an IR pass and the L-Ultimate with the 2600 DUO? The LUltimate would just cut that out.
No, IR pass only.
I guess i’m confused then, the question is about the L-Ultimate with 2600 Duo.
Don't confused John, just providing a real world data point that the original poster might find relevant. A data point if you will.
I’m still confused as to what you were trying to point out in reference to the L-Ultimate. Do you use a separate guide scope with an IR pass filter, and not bother with the second chip on the 2600 Duo when you use the L-Ultimate?
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Hi everyone - is anybody using an L-Ultimate while guiding? I'd seen at least one anecdotal report elsewhere that this works fine with the 2600MC Duo's guide chip, but I'm cautious since it's just 3nm bandpass, so very little light reaching the guiding chip. I know the L-eXtreme will work fine at 7nm, but I'm hesitant given the halo risk. I'd really appreciate any real world feedback! I'm looking to use this with my Zenithstar 61 (f/5.9 360mm focal length).
I live in Bortle 7 skies. I switched from the 2600 MC Pro to the DUO. Shooting at F7 with the L-Ultimate and the DUO, guiding was very difficult. Obviously varied with different targets, but sometimes there was only one faint guide star visible. Piece of cake with the L Pro, but frustrating with the L Ultimate. ! So I've sold the DUO, and have gone back to an OAG. No comparison!
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Wow, thanks everyone for all the feedback, this is very helpful. Now I feel confident giving the L-Ultimate a try myself. Hopefully this thread will help others as well. I struggled to find much information elsewhere. I'm using an AM3. With no filter I'm getting 0.4-0.6 total RMS error at 1-2s exposures with low gain. Sounds like I'll just need to increase the gain to use with the filter.
What scope?
It depends a lot on the F ratio and FL.
For me it worked well on a TOA130 (F5.4 / 700mm),
BUT it did not work on my CDK 12.5 (F8 2540mm).
sam
For me it worked well on a TOA130 (F5.4 / 700mm),
BUT it did not work on my CDK 12.5 (F8 2540mm).
sam
Depemds on the scope. The DUO works with L-Extreme on my 165mm f/5 mak-newtonian but not on my 10" at f/12.
On the 10" I have a piggyback guidescope that I can use, but at 3000mm focal length guiding is always better with the DUO, hence I use the L-Pro with it.
Same mount and tripod (only the OTA changes).
On the 10" I have a piggyback guidescope that I can use, but at 3000mm focal length guiding is always better with the DUO, hence I use the L-Pro with it.
Same mount and tripod (only the OTA changes).
I don’t use an L extreme but Askar D1&2 filters with a duo on an Askar 120 APO, No problems, either lengthen the guide exposures or push the guider gain. The 220 will take it.
Wow, thanks everyone for all the feedback, this is very helpful. Now I feel confident giving the L-Ultimate a try myself. Hopefully this thread will help others as well. I struggled to find much information elsewhere. I'm using an AM3. With no filter I'm getting 0.4-0.6 total RMS error at 1-2s exposures with low gain. Sounds like I'll just need to increase the gain to use with the filter.
What scope?
Zenithstar 61 (f/5.9 360mm)
Hi,I use an L-eXtreme filter with my ASI2600MC DUO on a 250mm Hypergraph at f/3.4, and I’ve never had any trouble finding guide stars, even in very faint regions of the sky. I typically guide with 2-second exposures, and the stars are bright enough for reliable guiding.While the L-Ultimate has a narrower 3nm bandpass, I believe it should still work fine, especially with your f/5.9 Zenithstar 61. A shorter focal length and the DUO’s guide chip sensitivity should make it manageable.Clear skies!
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