Hi Brent, i have a C925 and recently bough a hyperstar v4. i understand about bandpass shift but can i still get useable results with my Altair triband filter v1? i use a Altair 26C imx571 colour sensor. i mean if i could afford theIDEAS NBX UHS or the new Optolong l extreme f2 i would. it would be a shame not to just junk the filter i currently own if it isnt shifted too badly at f2.3 which is my current imaging rig. would be glad to hear your thoughts. thanks Des
this follow on video may answer your question ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-IudhLAjqD8E.html the short version is the more narrow the bandwidth the more signal loss you will have at lower f/. If the bandwidth of your filter is large ( maybe greater than 6 nm) then no problem, if the bandwidth is smaller, then you are throwing away (filtering) the signal you want.
I don't know all the differences, but would bet it is pretty similar. There may be a few different bolts, but it has to be assembled somehow - and I would think they make it serviceable if someone ships it back.
The last bottom screws, not the OTA just mount itself. What kind of tool did you use to remove these screws? Are they star hexes screws or just hexes and what size did you use please!!!
Thank you so much for this Brent. I will look to do this to mount the 1100 edge OTA on a TrackTheStars Panther Alt-At mount now. I am still trying to identify what dovetail bar is needed however. Great video ! Neil
I mount my control computer on top, and if using a hyperstar I also have a guide scope on top of the OTA. I also have a dove tail handle that I attach on top when lifting or moving to OTA.
Unfortunately these instructions do not cross over to the CPC 800 - everything falls apart when you flip the mount to the other side to access the handle screws. It doesn't have them, AND the CPC appears to be permanently attached to the OTA - there are no other bolts accessible bolts or anything else to access to unscrew :(
There were a few snug connections to get loose and it did take some leverage to get the side clamps to disengage. I found the trick of laying it out like I did in the video let me use a lot more force without worrying about dropping the scope.
Hi Brent I just saw again your videos after a few months. Now I can see why the IDAS NBZ filter has a 12nm band width and works perfectly with the hyperstar C9.25 Edge (V3, f2.3) and at f10 too. After this, I have a question: would a 12nm narrow band regular astronomik filter would perform differently from the 12nm MaxFR filter at f2.3? What about f10 or f7?
The bandwidth and what makes MaxFR special are two different things. Bandwidth is the characteristic of what wavelengths will be transmitted. 12 nm is 12 nm, and they will follow the same transmission trends based on f/ that I presented. MaxFR is about the manufacturing process that Astronomik uses to produce the filter. I would assume it to be the specific materials, thicknesses, layering, and coatings applied to the filter to reduce glare, reflections, and protect the coating.
Thanks. I think the NBZ design is a little different since it’s a flat top transmission so it can reach out the maximum value at different f-ratios. Astronomik seems to have a different approach. In the end, no matter the design, what is important is the performance and these Astronomik seem to be quite good
Thanks for this very helpful video and your timing was perfect! I just decided to defok my CPC1100 and there was your video, just uploaded! Thanks again. Clear skies!
Thanks, I deleted my note about removing by just taking out the 4 screws. The arm cover removal to give access to the bolts at the bottom to relieve pressure makes perfect sense. Mark
Thanks so much for your experimental approach regarding filter bandpass and f-ratio on a range of optics used for astro-imaging the results have enormous implications not just saving money. My own imaging set up uses a Samyang 135mm operating at f/2 but I have been using the vanilla 12nm Astronomik Ha filter both with a modified Canon 700D DSLR and more recently the smaller sensor ASI533MM-Pro. I haven't noticed vignetting with the dedicated 533 but often wonder if buying an Astronomik 12nm Ha MaxFR filter would realistically improve the collected Ha signal? Theory would suggest that a pre-shifted 12nm Ha filter should allow a higher passage of Ha photons at f/2 but perhaps the wide peak of the vanilla 12nm filter is broad enough to pass the light anyway? Lacking a spectrometer and realising the filter lottery out there with good, bad and indifferent samples being sold who knows or can even realise? Would you be able in the future to undertake similar testing comparing tbe performances of vanilla and MaxFR filters for users to make an informed decision over purchase? As you know the Max FR filters have a premium price and perhaps at f/2 for no practical advantage. Thank you again for all you have done on this topic. Regards, Steve
I don't have evidence of this, but I think part of the premium price of maxfr filters is the quality control astronomiks provides. Also, the qc matters way more for ultra narrowband where very slight error is catastrophic. At 12 nm bandwidth, the qc doesn't have to be as stringent to still work great.
Hey Brent, I really appreciate you sharing the comparisons between the 12nm and 6nm MaxFR filters. I'm considering a set of these and was curious on your thoughts with my two scopes: An Askar FRA300 (F5.0) and a Skywatcher Quattro 150pm (6 inch newtonian) (F3.45 with coma corrector/reducer). So I have an F5.0 and F3.45 system and want to get the best set of filters to use with both scopes to maximize signal to noise and have nice stars with little to no halos. Which set of Astronomik filters would you recommend in my scenario? Thanks.
if budget is no object - go 6 nm. if you want all the signal you can get, go 12 nm. at f3.45 incident angle is ~8.2 degrees - so look at the chart at a time stamp of 35:00 and compare transmittance at ~8 degrees. The 6 nm will have a little attenuation at the higher angles (down to ~80% transmittance). without doing the simulation... the 6 nm filter on your Quattro will probably make its light collection closer to f/4 ish. on my hyper star the 6 nm filter was giving a response closer to f/2.5 so maybe it won't be so bad for you? the 12 nm filter would give you your full f/3.45 signal. My testing was in a bortle 5/6 zone, and some of the comments indicate the benefit of the narrower filter may be more significant in higher light pollution conditions. some drawbacks on the 6 nm are that you may need longer exposures for you AF runs (I was doing ~8 second exposures to get confident and reproducible focus runs) the 6 nm filter will not give you better resolution... it will provide better signal to noise at f/5, and somewhat better signal to noise at f/3.45 compared to the 12 nm filter. Do these differences justify the difference in cost for you? that is up to you. depending on the currency conversion rates it can be cheaper to buy directly from astronomiks in Germany than to buy elsewhere. you may find my updated video of a little more help: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-IudhLAjqD8E.html
and remember for the chart at 35:00, it is the area under the transmittance curve from where the photons are coming from on your scope - not just the transmittance at the highest angle - your quattro will be somewhat like my hyperstar. if you really want to know, download the python code and put in your scope parameters. my other video gets into this in more detail.
@@astrocrypto8438 after all of my filter adventures, I came to appreciate the importance of parfocal filters. on fast systems backfocus is critical, and if your filters are not parfocal, you may need different spacers for each filter. I now use only Astronomic filters for everything. this is also very important if you do OAG. for your Bortle zone... and scopes... I would say go for the 12 nm and spend the cost difference on other things.
By far the deepest analysis I’ve found on this topic, Brent. I use the IDAS NBZ for Hyperstar imaging and, according to the specifications, it is also a wider band filter both in Ha and OIII. I have a C9.25 EdgeHD with Hyperstar V3 and the ASI071. When I got this filter the increase in SNR was evident, compared to the previous narrow band ccd filers from Baader (which are engineered for a slower f-ratio). I’m considering going for f10 mono imaging. In that case, I think filters in the 3nm to 5 or 6nm FWHM range would be useful, because of the very low angle of incidence. What’s your opinion on that?
The down sides to narrower band are cost and you may need longer exposures for auto focus runs. Otherwise it seems like 3 nm would be awesome for those focal ratios. Keep an eye out for reviews on halos
That’s something to keep in mind. I’ve seen some threads in CN about halos with even the most premium brands. And definitely those can come from a lot of sources as you have shown. I’ll have to inspect some of my images to check where those halos were produced
Excellent review. I learned a lot - thank you. I'm getting significant halos with Astronomik Type 2c Blue and Green 36mm filters on an f7 APO refractor. Astronomik referred me to your video to understand more about halos. Since your video doesn't go into the why too much, I'm still left not knowing what to do to correct them. I'm getting a new set up at f7.5 but with Chroma filters and I'll see if they help. I understand shorter exposures with faster optics is the direction of good for halos - so I'm not very hopeful. On your question of the background difference - I live in Bortle 5 skies according to the Clear Outside App but am on the edge of a city of about 100,000 people. So to the East my sky backgound is higher than to the West. It is easily visible with the naked eye. If the 6nm images were taken to the East and the 12nm to the West from my location, I expect it would confound the result. Something to add to your possible explanations.
Look for another video on my channel called "Bandwidth choices for narrowband imaging with fast optics" at the 6:53 marker I talk a lot more about how to figure out where the halo is originating from. The size of the halo tells you this distance from the sensor that is generating your reflection. In my case it was optics in the camera, not the filters. And the strength of some reflections may be very wavelength dependent.
Thanks for your analysis. I have struggled with my Baader 3.5/4nm filters for fast optics on both RASA 8 and Samyang 135mm f/2.0. Different from the RASA 8, Samyang 135mm f/2.0 results were disappointing ( The target is Veil nebula, which is good for both Ha and Oiii). Now, I know the reason. Thanks again!
Thank you very much for your effort in comparing the filters. I am interested because I am considering an upgrade from my 7nm filter set to a 3nm set. I am not an expert so please correct me if my concept is wrong. For the contrast issue, assuming you can measure the background correctly at point C, then subtract it from A, what is left should be the pure signal. When I see that both filters have the same 'jump' at B, I think it is perfectly normal and it just shows that both filters pass through the same amount of signal. But I think there should be real benefit for a lower background with a 6nm. The sky background is not a perfectly 'smooth value' added to the signal but with noise. Cutting the background more should mean this noise getting lower. Then during processing we can stretch the 6nm images more with the same visual level of noise. That's where the better contrast come from.
Thanks. I have thought a bit since I posted this. 1. I am in Bortle ~5.3 (according to some app), after talking with a few other people, the differences would be much more apparent if there was more light pollution. 2. The real definition of contrast does not use the background subtraction that I used, so yes, there is probably some benefit to using the 6 nm, especially if there is more light pollution. However, if you are using fast optics (< f/2.5) you may be losing more signal than just reducing background. To go to 3 nm filter, you probably need to be > f/4 ish? to not have so much band shift that you are cutting a lot of signal (guessing, not running a calculation) I did a few other videos with some corrections to this video.
I am not sure what you mean. if you are using the 6 nm filter, you could set the lens to f/2.6 as that is about what the filter will pass, and maybe it will give you a little extra depth of field for good focus? if you are using the 12 nm filter, you can set the lens to f/2 and get most of the light through the filter.
That's actually very accurate, I use this lens and you do notice that the signal does drop off in the corners as you describe. The lens really isn't setup to take a flat field like many of the telescopes out there so I always just thought that was the reason.
I know you said the Hyperstar at f1.9 with the 6nm stops down the optics so it’s better to go with the 12nm. I also noticed you are in a bortle 6 zone. My question is do you believe the same holds true for those of us in a bortle 8 to 9 zone. Or would the 6nm be better due to the extra sky glow?
That is a great question. I think it comes back to the statistics of signal of interest and sky glow, and that you just need 'more data' (more subs) to help remove the sky glow. I don't have a quantitative answer right now, but I think stopping down the scope does more damage to the signal than the narrower filter benefits the signal. The rate of real signal accumulation is the most important (so 12 nm) seems to be the key factor, and being above the read and shot noise of your detector. I provided links in the description for a paper from Abby Road Observatory (see the link for karmalimbo) Some of Jim's other papers on that that server get into simulating sky glow, but not in the context of exactly this question. Look up a video with the title "Deep Sky Astrophotography With CMOS Cameras by Dr Robin Glover" around the 50 min mark is a table based on f/ and bortle that gets at these concepts. I will think on it and see if I can do another video on these topics. I think Cuiv the lazy geek channel has a video about light pollution in Tokyo and signal as well.
Very informative. I am using the Baader cmos optimised f2 NB filters, 6nm Ha, 4nm Sii and Oiii. Reasonable results so far on Samyang 135@f2 with asi2600mm/mc but early in the testing so far. Would be great to have details on your tilt adjustment rig - I have built one but it is very cumbersome to use. Cheers, Des
hm, I bet you are stopping down your lens to f/2.5 with the 6 nm, and even more with the 4 nm, probably down to f/2.8. I may do a follow up looking at smaller bandwidth filters and for lenses. I think I also want to refine my index of refraction estimate, I thought of a way to get that a bit more accurate. What I learned was that the narrower filter was rejecting more real signal, than it was rejecting background for a net loss in quality.
Wow! An excellent and thorough analysis of what is actually happening with these filters. Definitely surprising that the 6nm filters dont suppress a lot more of the background light pollution. Maybe you might get different results in a Bortle 8 or 9 location? I am in a Bortle 6 location so my results should be similar to yours. I think Quiv the Lazy Geek should check out your video. I really really appreciate your attention to detail and I actually understand what's happening now. As a side note, you mentioned corrector plate alignment - it would be great to see a RU-vid video on how to collimate Hyperstar on an Edge HD. I am finding it very difficult to achieve round stars over the entire sensor (and I'm using a micro 4/3rds ZWO294mm Pro). You definitely have a new subscriber!
One of the best videos I have ever seen related to this topic. I am currently in the process of selecting narrowband filters for Samyang to be used probably at f2.8. Your video clearly confirms that blue shift risk increases with narrower band width. I was thinking about 6nm non MaxFr filters from Astronomik. Now it's really good question if this makes sense at f2.8.
Interesting! I image with a OSC and a 5nm dual band filter. I wonder if a 12 nm filter like the L-enhance wouldn't be better when using an f/2 camera lens like the samyang 135mm...? Either that or stopping the lens down to f/4. What are your thoughts on this?
Excellent video! I've been looking for something like this for a while. I want to run these calculations for my optolong filters which are 7nm and I use a Hyperstar 3 on an EdgeHD 1100 which is F2 I believe.
It would be hard to get say 15 x 500 sec subs for both filters over one night. So many things are going to change especially with the elevation of the scope towards zenith. So much to consider when going the Hyperstar way. I just realised that my Antlia 3 nm Pro NB filters "might not be" working all that well at F2 as they suggest F3 as the best solution.
these testing nights are educational. I may do some more comparisons but it is twice the work... and not as ideal for image workup. for your current filters - you have them and they actually get f3 that isn't bad, and it is a big investment in more filters for what is less than a full stop difference. Are the antlia filters blue shifted for fast optics? It would seem they would need a specific shift for that narrow of a bandwidth and a particular f stop.
@@BrentMantooth The Antlia website says? "Blue-shift data show that Antlia 3nm Pro filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signal and meets the requirements of fast optics like Hyperstar and RASA.". I have the filters for normal imaging F5.6 on my refractor. I haven't used them on the SCT yet as I am waiting for my Celestron OAG to arrive (tomorrow) and then I will see what they look like at F7. There is a significant difference between the Antlia Ha 3 nm and the Optolong Ha 7 nm filter. I really want to try my Antlia 3 nm on Alnitak but the weather has been against me for months. I am mulling over getting the Hyperstar, but as it is 90 mm in diameter, I am a bit concerned that it will impact the amount of data going into it. So much to consider with AP!!
@@stephen2615 haven't analyzed signal yet, but reflections are very different from f/7 to f/2. I mean there is one less mirror in f/2, and we are talking about reflections...
I am in the process of analyzing the HyperStar data. Like you suggest, I think I am going to need that 15 sub data to make sense of what I am currently seeing. I was hoping to wrap up an analysis, but, like many science projects, I keep finding more questions. I will post part 2 soon.
Hey! Brent Paul here from HS group. Thanks Brent for that thorough analysis for f7. Regarding the contrast and background ADU and that 60% signal you’re getting. Both 6 and 12nm are almost identical on those background signals. All except for tighter and smaller stars which you have a clear results here. I’m guessing here but maybe the nebulosity may have some influence to its proximity to the horsehead designated as background? Would you think an Ha target that has a clear edge side in contrast with darker open space would yield a more isolated Ha signal and accurate ADU background?
I can hardly wait for the Oiii filter review. My 6.5 nm Oiii filter and Alnitak produces awful reflections in some of the strangest places. I now have Antlia 3 nm NB filters but it has been awful weather so I haven't had the chance to use it.
soon, switching the scope over to hyperstar tonight so I can image tomorrow. [spoiler alert] At least at f/7 the OIII MaxFR was showing halos for both 6 and 12 nm. Talked with @deepspacedad and he didn't see reflections, at least with HyperStar.
@@BrentMantooth I have a QHY 268M (and other cameras, way too many cameras) and I am interested in a Hyperstar for my EdgeHD 9.25. Unfortunately, Starizona hasn't responded to my emails about whether I can use it with the Hyperstar. None of the QHY cameras on the website list the 268M or the 600M but they list the ZWO 6200.
I know they can support full frame 35 mm sensors (probably with vignetting) - I have the adapters for my Canon R5 but haven't tried that yet. You should just need the right back spacing.
