Which Guide Camera Do You Need?
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- Опубліковано 23 вер 2023
- So I am guilty of owning one of just about each kind you can get. But really the only one I think I could ever need is the 178MM. It is great for all kinds of guiding and is a great planetary camera too. Even good for some DSO work. The new low light sensitivity champion though is definitely the 220MM. If you are looking for an OAG camera it's a great one for that.
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Thank you Ben for a super review. Clear skies forever and a day to all of you
Thanks so much for all your work. You’re an amazing giving person. All the best big fighter.
Thank you Jim.
Great stuff, slowing building my rig and this is the perfect video for helping me decide on the auto guiding aspect of it
Glad it was helpful!
Great first hand experience and explanations! Thanks!
Glad it was helpful!
Thank you for this information. I am thinking of using an OAG on one of my rigs so it looks like I'll get a 220 to go with it.
My 120 with a red filter, that you recommended, has been working very well for me with sub .50 tracking in almost all cases. Thanks
Great to hear! The red filter trick does not get enough prime time.
Great discussion!👍👍 As a follow-up, I will add a few more thoughts, because, IMHO, choosing the best guide camera also requires one to assess the tracking ability of the mount, the focal length of the main optics, and typical atmospheric conditions. So...
(a) In the case of harmonic mounts that do not have an encoder on the RA axis, the tracking can deviate from ideal extremely quickly, which can only be addressed by shooting with a rather short focal length, and/or by using very frequent guiding corrections. This is also the case with GEM/fork mounts with average/low quality gearing, or any light mounts or large OTAs when the wind is gusty.
So, if one has such a mount, and is shooting with a 135mm or 200mm f.l. lens, it may be possible to get away with guiding corrections once every second, or perhaps every few seconds. However, with the extremely demanding CMOS cameras today, typically with pixels less than 4um wide, any deep sky imaging at moderate or long focal lengths becomes exceptionally 'picky'. Therefore moderate/long focal length systems, and either standard harmonic mounts like the AM5 etc, or a 'budget' GEM/fork mount, or any system susceptible to wind gusts, it will be necessary to do guiding corrections two times per second (i.e. '0.5s exposures') to get good results,. That means that the guide cam must be quite sensitive to continuously detect multiple stars in its field of view with really short exposures.
(b) Unfortunately, using really short guiding exposures increases the likelihood that the guiding will end up erratic because the guide cam could react to scintillation of the stars, rather than correcting tracking errors. To deal with a guider 'chasing the seeing' on nights with moderate/high atmospheric turbulence, there is a great need to guide on multiple stars across a wider field of view, which means that a guide cam with a wide field of view is also necessary.
(c) Furthermore, as mentioned in this video, a high-sensitivity guide cam is quite important if it's used in an off-axis guider. Additionally, a high-sensitivity camera is also extremely important if the guide scope has a longer than typical focal length (e..g. to guide precisely & accurately with long focal length main optics.), and/or the guide scope has a small aperture
(d) However, for those who choose to purchase a high-end GEM/fork mount, or those who use a harmonic mount with an encoder on the RA axis, guiding corrections can be made every second or two, and the the sensitivity of the guide cam is not quite as important.
that's a very detailed and accurate addition!
I guess 0.5 or 0.2 secs exposure in guiding can make a difference especially for older mounts like mine (As-GT Celestron) after having dismantled and greased it and got rid of most of the backlash on both axis. had a hard time before but now I'm regularly getting 0.3-06 RMS using an Svbony 305 (290mc)
@@actudoran Those are some impressive guiding stats for that mount! 👍
@@derekbaker3279 yes Sir I was blown away that's why I'm not selling it despite its age ... although the electronics have recently started to act up ... like it's reversing commands on Dec axis ... not recognised by the PC ascom ... reboots necessary etc ...
Excellent video! 👍👍 I use the 585 MC for guiding, works perfectly.
Yeah, I dont understand throwing color planetary cameras under the bus so hard. I think some people just haven't tried it because they haven't had to. 385MC works great too
@@mark2220 even my 678MC is totally fine for guiding
good info - thank you, I learned new stuff
Followed your advice and bought the 178 I have to say it is a great guide cam, I would never have considered it in the past
Great to hear!
I still use the 120mm but added a UV/IR Cut filter to get sharper star shapes. The one thing that improved my guiding significantly was removing the small 120mm f/4 WO UniGuide and using a 50mm guidescope with 242mm FL (SW EvoGuide 50ED). My guiding improved from oscillating between 0.40" to 2.00" to a steady 0.50" at all times.
Switched over from the ASI120mm with guide scope to an Askar OAG with the ASI174mm. It was expensive compared to the 120mm but I see a ton more stars and will also work with SCTs if I go that route in the future.
I use my Askar OAG with 220MM. Great guide in any situation, super sensitive, with my C8 SCT
Any guid camera is better then the 120mm :)
Good to know! I was looking for a good reason to replace my 120mm ;-).
Thank you for the review. looks like the 174 or 8 will be on my bucket list. I'm just learning my used AVX. I've had a few scopes / mounts, so I'm not a total novice. but, I am a beginner in astrophotography with guiders and the newt, AVX.. etc, etc. I started with the Svbony 105. and it was ok. I am currently using the ASI120mc-s. its a fun camera. gives great results. I'm getting the ASI224MC in the next few days. my scope is the Celestron 150 Omni XLT six inch newt. I have been doing the, pointing the mount basically north and then doing a solar alignment for the sun and solar system alignment for everything else. because its almost impossible to see Polaris here in the burbs of Chicago. do I need to get into the guide scopes and things since I basically do the planets,moon,sun and then simple stuff like Orion Nebulae, Pleiades and milky way?. my AVX tracks really well. it has had the hyper tune with the new bearing. I have to nudge it every 15 minutes or so if doing astrophotography. for visual viewing, I nudge it every half hour or so. if I stay with the Newt ( I love this scope ) should I go with a 30-34mm guide scope. or is a 50 ok? and can I use something like the Orion ST80 as a guide scope ? .
Nice video! My camera has an IMX178 sensor. It's not ZWO but I'm super happy with it. I use it with a guide scope but I want to try OAG. Greetings from Argentina 😄
very good video, thanks! Where do I get this blue ring wich is attached to your 290mm in the video? I also really need this "focus stopper" badly..
I got it second hand on cloudy nights
Is the 178MM still available? I can't seem to find it in stock anywhere.
Here is a noob question! I have the nexstar 8se on zwo am 5 and im trying to long exp (2m-5m). I get stretched stars even with 2m exp. Will a guide scope and cam combo help? if it will im thinking the 220 but before i pull the trigger I wanted to know what scope i should combine it with?
Very helpful. I have the 178mm. Any suggestions as to the best guide scope to pair with it? I am typically working with a wide field refractor but also intend on doing some planetary imaging with a SCT (and would rather not use an OAG). Thanks much.
a 400mm guide scope would do it with an SCT
What SCT are we taking about? They vary in size and FL quite a bit.
5" Celestron F10 SCT (its the tube from my 'C5+). My other scope is a 92mm F5.5 refractor. I am using a William Optics Uniguide (200mm) and it seems to be working well. I can add a larger/heavier scope to my mount without issues.@@TheNarrowbandChannel
I am new to this guide scope business and just bought the ASI220MM-Mini. Nothing but trouble. It does not work with APT, SharpCap, or PHD2 without an extraordinary amount of back and forth playing. The only way I was able to get an image on SharpCap was after I had connected the ASI220 to APT and turned on LiveView. With APT LiveView on an image immediately appeared on the SharpCap screen. Starting APT first was the only way to get an image with PHD2. Too many headaches with this guide camera.
Great review of these zwo guide-cams. Now I know why you shouldn’t use a color cam for guiding. May I ask what’s the blue ring you add to your 220 guide-cam ? It’s obviously to keep the focus distance when inserted in the guide scope, I’d like to buy the same 😅
That is a stop ring to put I back into to focus the same time each time.
@@TheNarrowbandChannel where did you get it?
The monochrome 178 seems to be discontinued and out of stock. Only the color one is in stock and I remember you saying before never to get a color guide camera. So maybe it would be prudent to make a video on the best replacement for the 178.
I'm using a ASI120mm on an SVBony 30mm/120mm guide scope and my guiding is not all that great. You mentioned using a longer guide scope to get better guiding with the ASI120mm. What FL guide scope would you recommend? My imaging scope is a guide scope the Sky-Watcher 50ED Evoguide with the ASI533MC Pro attached. Thank you
That is a very short FL for the imaging scope. I would check flexure. That scopes has issues with that based on a friends experience.
@@TheNarrowbandChannel I wanted a little wider scope for larger DSOs and it seems to work great... I added the Starizona field flattener and so far everything except guiding is good..
@@TheNarrowbandChannel 242mm FL makes for a little bit wider view than my 420mm other scope.
Since the 2.9um pixel 290 and also the 178 aren’t offered anymore, that leaves the choice between the 3.75um 120 with smallest FOV and the 4um 220 with a little larger FOV. I think the 220 wins on FOV for multi-star guiding, while having only slightly larger pixels. Would you agree? Or should we look for used 290 or 178? If so, doesn’t ZWO have a hole in their current portfolio?
Excellent review, thanks. Why do you dislike OAGs so much? In your opinion, what would be a better alternative for long focal length?
There are OAGs that are large enough for the 174MM. Player oner FHD-OAG MAX and Pegasus Indigo both have openings that are about 12x7mm (a hair narrower than the 174MM). IMO, for APS-C and smaller imaging sensors, the 220MM would be fantastic with the TOAG: the TOAG has screws to move the camera and prism laterally, allowing to move the guiding field of view to where the stars are, improving the odds of finding enough stars for multi-stars guiding, even with a small sensor at long focal lengths. Also, the size of the opening on the TOAG is about 7.8x4.6mm, just a hair larger than the 220mm sensor.
I have seen so many struggle with them what is why I say stay away from them. I used mine a few times. never had trouble getting enough stars even with the 120mm in it. But what I could never get to play nice was guiding. For some reason the software could never get meridian flips right and it would guid the wrong direction ever single time.
I run, or at least attempt to run, an OAG quite often with an edge hd8. It always gives me trouble. Finding stars are fine, like he says, but guiding is always a headache.
Every time I switch back to a small refractor and a normal guide scope, I'm reminded of how nice a simple set up is.
@@NG-VQ37VHR you are absolutely right, guiding an HD8 at 2000mm is definitely a lot more challenging than guiding a small refractor. That said, guiding an HD8 at 2000mm with a guide scope might be even more frustrating (and a lot more expensive) than with an OAG.
I have a question about the 174mm, I have to set the gain to 400 to see any stars using a OAG on my C11 Edge. Is that normal?
Yes. Oag is a pain in that respect. That is why they are so hated.
depends on the OAG you are using aswell. the bigger the prism, the more light will hit the sensor.
What guide scope is it? I have been searching for 400mm guidescope like yours. Link?😊
It's a 70mm. I think astromania makes it. But I am sure a few other brands carry it too.
@@TheNarrowbandChannel Thank you. By the way, thanks also for clarifying the reason why colour camera is not good for guiding. Before I thought that it is because it is dimmer, now when I think about it, it all make sense. Guiding is bases on pixel and subpixel values and Beyer rggb pattern could throw guiding off. Wish you all the best😊
Off topic: Hace you ever tried an astromodified micro 4/3 camera?
NO I never have. I have to many dedicated cameras for it to modify one.
About the 220mm + 160mm (SV165) scope for Nikon Zf mirrorless with lenses from 50mm f1.2 and 600mm f6.3.
Is a good combination, seems overkill
At the start of this video you mention the 178 but at the end it is now the 174. I am a bit confused and since I really need to go with something other than the 220 that I just bought it is the 178 or the 174?
He meant 178 😅
They're all _Guid_ cameras if you ask me.
Cannot argue with that.
Thanks Ben. I’ve currently got two asi110 mini guide cams and once I got used to focussing them, they work well. I have an asi2600mc duo on order so I’m eager to find out how the 220 performs. Hope to see another brilliant video from you soon.
The 220MM is pretty solid performer. It can really pick out some faint stars.. @@Imabloodyhuman
“Guide” 🙄
@@Imabloodyhuman
Hi Ben. Could you maybe do a video like this, but with cameras for all around. It seems that everything below USD1000, are called planetary cameras, Above that price, of course you get cooled cameras, but really. Can these "planetary" cameras not do deep sky´s, nebulas ez. There are no sweet spot between USD500-1000, just nothing. Personally I could stretch to USD600, but will not get near to 1K.
Zwo does have non cooled versions of their dso cameras, that usually come in under 1k. You can definitely shoot without cooling and get good results. You just have to use shorter length exposures, which you can make up for in volume and stacking.
The main difference between the planetary cameras and zwo's non cooled dso cameras, is the sensor size. A camera meant for planetary is going to have a much smaller sensor and is doesn't need cooling since your exposures are going to be very short. Just because it isn't cooled, doesn't mean it's meant for planetary, but a planetary camera would not do well with DSO's due to the much smaller sensor and a few other factors.
Another budget option is getting a used dslr and shooting with it. When I started, I bought an old Canon 600d(t3i) for around $100, and it was so great I bought a second and astromodified it. I still have them and bring them out once in a while.
You get a very large sensor for super cheap, and I would even set up a box fan to blow across the camera to help cool it. It really did make a difference in reducing noise and allowing longer exposures.
If you're mechanically inclined, there are even tutorials for attaching a cheap peltier cooler to the 600d.
There are absolutely ways to astrophotography on a budget. You just need to have a few other skills. My first guide camera was one I made from sourcing the asi120mm sensor on Amazon for $30 and then designing and 3d printing a housing for it because I couldn't afford to buy the asi120 itself, eventually upgrading to the sensor from the asi290mm. It was on Amazon for $50. I do now own the zwo asi290mm, but those home made ones did the job for years.
I would encourage you to look for a used camera. Start checking out Cloudy nights. I know I got my 178mm cooled there for 450 and my Orion G21 cooled for the same price too. If budget is your limit used gear is a great way to go. Sometimes yo can find 1600mm Pro for 600$ on there.
So for a guide scope you would recommend the 220 over the 174?
If you are using an OAG
@@TheNarrowbandChannel I am going to attach the guide scope to the top of my stellarvue 102T refractor.
I would not, certainly not with an OAG and a huge SCT ;-) I need every star I can find and the FOV of the 174 is much bigger than the FOV of the 220mm.
As a noobie I’m still confused as to the relationship between imaging camera and guide camera in terms of sensor size and pixel size . Currently using canon t5i un guided . Sensor = 22.3 x 14.9
Pixel size = 4.30um
Love this channel and hope your doing well !!
For now do not worry to much about pixel size. :) there are other things to worry bout. Like camera heat.
Which model scope is that 170mm ?
It's SVBONOYs 40mm guid scope.
I guess I don't really understand the extreme point of view on a OSC planetary camera as a guide camera. personally using the 385MC to great success with guiding (guidescope for my small refractor and OAG for my Newt and RC.
Stars are broadband objects. The star light will come through on every pixel regardless of the bayer pattern where there is a star to be seen, or so I think would make sense. It would make sense if for example you were using a narrowband filter and you didn't want to waste the Blue/Green pixels on HA data.. but its all broadband. My image turns mono on the guiding software as soon as I tell it that camera is for guiding.
I must be missing something.. but again, it's working great? EQ6-Ri with 0.4 - 0.6 RMS on a nights with above average seeing isn't anything I feel I need to run out and buy a new camera for. Maybe just me.
You need to understand the bayer pattern and how a mono sensor has more resolution then a osc to see what i mean.
@@TheNarrowbandChannel I would not buy a color camera only for guiding. but one can use a color camera as a guiding- and planetary camera with no issue (as I did with my very cheap 678MC). it really doesn't matter. you will see the exact same result because newer color cameras are very very sensitive and there is no use case anymore for an even more sensitive mono camera. still as I said, if I buy a guilding camera, it will be mono.
Are you okay??
I haven’t seen a video. Came here to check in.
yeah. me too@@taylorlimbeck6854
Doing good. Fatigue has been getting to me though. But chemo is almost done.
happy to know that you are doing well. It’s been a while since I saw any videos from you, and I wanted to make sure that everything is fine@@TheNarrowbandChannel
@@TheNarrowbandChannel my 3 year old was diagnosed with a rare soft tissue cancer about 12 weeks after he was born. He’s been in remission since December of 2020. He doesn’t remember chemo, surgery, any of it. I hope you get to ring the bell soon.
I have to say I disagree about guiding with an OSC planetary camera. I use the ASI462MC and always have plenty of stars to do multi star guiding. PHD2 uses a mono image for guiding. It’s very accurate.
It’s a matter of preference, if you’re using the camera also for planetary imaging.
You can use them. You just won't have the resolution. And turbulence interferes with them more. In short you need about twice the FL on your guid scope to use one. That is why I made a big deal about them.
@@TheNarrowbandChannel
I don’t mean to be opposing. But is not as you say. PHD2 uses a grayscale image of the FOV in order to guide. No interpolation at all. So, it doesn’t loose resolution when guiding.
@@alfredobeltran611 That is partially true but bayer matrix is applied at the firmware level before it ever reaches PHD2. Ask any experienced astrophotographer, the mono will result more details always.
@@TheNarrowbandChannel Well, about experience, let me tell you that I’ve been doing astrophotography since 2011 and some of my images have been chosen by Sky and Telescope and Astronomy Magazine.
My point is not that you can do better with mono or OSC; it’s just that is possible to guide very accurately with an OSC planetary camera (nor so many years ago it wasn’t). For many years I used an Orion Starshoot Autoguider (mono) and the ASI462MC just gives more stars to guide in a short exposure (2 seconds) than the SSAG with 5 seconds exposure with the same optical train. Not to mention that it also makes possible to guide on the infrared, given its high sensitivity in those wavelengths.
Anyway, my point is that if the user chooses one or the other, with both will be able to guide accurately.
Regards,
Alfredo
@@alfredobeltran611he never said it wasn't possible. He just stated, everything else being equal, a mono sensor will be more accurate. Which is a fact that isnt controversial. You're arguing a point that he never disagreed with in the first place, you weirdo. Don't get so offended just because he doesn't prefer the guiding camera you happen to have. Geez.