My New Autoguiding Camera (ZWO ASI120MM Mini) for PHD Guiding 

I'm 70 years old, and am finally able to get started with astrophotography after years of using binoculars and a friend's 6" reflector. I'm putting my kit together now, and can't thank you enough for your videos and website. Your videos get better each time, and I've learned so much thanks to your clear, concise narratives. Keep up the good work!

Not only your astrophotography but also your cinematography is awesome !

Trevor, I appreciate the videos you're making. I think they encourage a lot of people to get into this hobby. Regarding this video specifically I have a few comments which I think are important: 1. When deciding on a guide scope. It is not the focal length of imaging scope and guide scope that solely determine what's best. It is actually the image scale ratio between the two. In your case, your imaging scale is around 1.5arcsec per pixel. Which is relatively forgiving for seeing and errors. Your guiding scale is roughly 3.4 arcsec per pixel. So the ratio between the two is about 2.25 which is a very good ratio. And that is the deciding factor on which guidescope/camera to get. 2. Regarding the PHD2 RMS, the number 1" you gave is not correct at all times. It depends on the image scale of your setup and seeing conditions. But as a beginner ball park I agree its a good measure to start with. 3. The statement that what's important is the image is true. However, it is important to emphasize that the processing skills are as important or maybe even more than the acquisition skills. Your final image is beautiful, but there is a lot of processing involved and a lot of experience needed for that. Its not going to just miraculously happen when taking a sub. 4. This is a color camera. Which means that in practice your resolution is even lower than 1.5"/pp that I mentioned in 1. Because of the way color camera works. So when doing really wide field targets the fine resolution is not that big of a deal. Anyways, just wanted to clarify a few things for people that follow this. Keep up the good work!

I too am in my 70s and getting started in Astrophotography...Same as Peter I thoroughly enjoy and learn so much from your videos...All I can say is thank you thank you thank you

I got this guide scope last year. What a HUGE improvement over the old 50mm Orion mini. It's a fantastic, all metal construction vs plastic, has excellent optics vs passable, and a buttery smooth focuser vs no focuser at all. And it's about the same price that Orion charge for their lesser guide scope. This thing is a winner in every way. I'm sure you'll love it.

Holy crap, “it was 200 Canadian so about $10 US” wow that got me laughing hard.

One of the biggest things that helped me when I started guiding was slightly longer exposure on the guide cam. Instinctively I thought shorter would be more accurate but ended up chasing seeing conditions, much more time waisted than I’d like to admit. The yard looks great by the way!

Your videos keep me motivated in astrophotography😄. Keep up the great work!

Thank you for inspiring me to buy a DSLR and start Astrophotography! Clear skies:)

The video you posted about beginning the astronomy 🔭 journey inspired me to get a10” dobsonian. I took it out for the first time last night and was completely blown away! Thank you for your videos and insight.

Great video , I took my first picture with my cellphone hand held of the moon in late March of this year . That started my journey in astrophotography. I just imaged the lagoon nebula a few nights ago and freaked on the results , no wonder people focus on nebula so much. Now tonight I start the autoguiding part of this hobby , the game changer as they say , at first all of it from the beginning is mind bending but after watching videos over n over n over I get it . Thanks again this video is what I needed as I have the asi 120 mm mini and a 60mm guide scope for my c8 that has the focal reducer from celestron. I’m only concerned about the focal length at 1280 but if I have to go to a larger guide scope I will . Have plenty of time till new moon .

I'm 15 now I have a small but cute telescope. I hope one day I'm gonna be like you ♡ Ily so much.

i did't think this possible. . . to make cinematography from a backyard of a 2400 ly nebula! I sound so nerd, but I am amazed as hell. Someday someday I hope will be doing this also. 👍 👍 👍

Trevor, thanks for sharing this. Thanks for showing Rudy!

Great video as always Trevor... one thing I'd like to point out -- the ST4 guide port use is kind of considered "old school" now. Using the ASCOM interface allows PHD2 to get the declination and side of pier from the mount and use these values in guiding calculations. -- ST4 still obviously works, but one less cable to use and better accuracy if you already have ASCOM configured for the mount.

Thank you Trevor for your videos, they inspired me to start astrophotography. That shot of the Veil was beautiful!!

This hobby is fun, not counting the staying up all night. At 63 it's not easy to stay up past 9 pm. However that being said, I want to advance from observing to astrophotography. Love your videos, very professional. Clear skies!

Thanks so much, have been following your channel for a while. Great final image! I just ordered the Sigma 150-600 Contemporary to use with both my Nikon D750 and D7200, both for astrophotography and wildlife/birding. Thought it would be a great way to get a lens that can handle both, and basically allow me to have two amazing photography hobbies at once. Next is the iOptron iEQ30 Pro mount, along with a light pollution filter and other items. Keep up the great work; your videos are very inspiring!

This picture says a thousand words and two of them are: astounding sharpness!

What a superb video Trevor. I agree 100% about obsessing over the PHD2 graph. I've done it many many times when I'm imaging with my Losmandy G11-Gemini2 and Altair 115EDT and cameras. After a 5 minute sub. If the stars look round that's okay with me despite what the graph is showing you.

Your videos just keep getting better and better, awesome videos. 😄🤟 Plus I love astronomy. 😁

I will buy my first Astrophotography setup next year!!!

I sit here waiting for my telescope and camera to arrive and with video you post my impatience to get properly started with DSOs is growing exponentially! Keep inspiring, Trevor.

Thanks 😊 for uploading your images in social media sites...and video in youtube...have a great day.

You are turning into a real comedian.... love it! BEST astrophotography channel anywhere!

I just bought the zwo asi120 on your recommendation, and downloaded the software as well. thank you for the video and will share my images in the future

WOW...I love your Presentations...I purchased the ZWO ASI 120mm mini based on how well it works and because of your detailed Presentation I found your Williams STC astro narrowband...they are out there but maybe on backorder..Thanks sooooo Much for your Presentations...as soon as I can find my CC I will join your Presentations...

Excellent Information Trevor! Thanks so much for the inspiration! I'm just starting out so I need all the inspiration I can get. I have the EQ6-R pro and the Skywatcher 100ED triplet. I'm so excited to start using it, but too much snow here in Spokane WA right now. I'll just keep watching your Utube guidance lessons until I can take my rig outside. Thank you! John

I use a Astromania guide scope. Also very inexpensive and works great with the 120mm

All I can say is Wow! Outstanding image. Time to get back to imaging. C11, ONAG, ZWO OSC camera. Now to pick a good target.

Hey Trev, great video. Observatory is almost done and soon the EDGE HD 800 will be mounted, on my 3700lb of concrete atop my metal pillar with the all important AVX PLATE! I appreciate all the pointers in this video siting all of the numerous albeit basic steps needed to be completed, in order to capture awesome results. I think watching your videos will allow me to keep at least some of my hair when I cure everything up. Cheers my friend. Your work is so inspiring!! Tony V

I'm learning quite a bit from you Trevor, please keep up the fantastic work!!

New sub here. Because of you I just recently ordered the sky adventurer pro bundle. So excited! Please don’t ever change your style of your videos. I love how informative it is, the cinematography is great, and I absolutely love the music. It compliments your videos so well. Looking forward to see your channel blow up. Clear skies, from St. Louis, MO.

You are such a great motivation for us..Keep aiming and May you get clear skies :)

Great video Trevor. There really aren't that many videos that just simply explain the basics for us beginners. Really helpful! Thanks 😁

WOW WOW WOW! The best educational, exciting video to date. Trevor, I have been a loyal subscriber for sometime, and your presentation and astronomical skill set have peaked. Love the monitor, big improvement. Since retirement from the airlines a year ago, I have been working up to the astrophotography challenges. Between you and Dylan at Starstuff, I am ready now to attempt my first serious image. THANK YOU!!

With PHD2 I found it's a good idea to run the "Guiding Assistant" under the tools tab. It records a few minutes of guiding and then gives suggestions on a few settings. Can't hurt to try the suggestions it gives and if it doesn't improve you can always revert to the default settings. For me it gave a slight improvement to total error... Maybe it can help on nights where guiding won't behave properly.

That image is amazing. It looks almost like a 3D render!

Always love your videos Trevor, very informative for a new beginner like myself here in Northern ireland. Have the ZWO 120 mini, great wee camera.

Very helpful - I have exactly this guide scope & camera arriving next week!

"...stuck out there without the right extension tubes..."- I learnt that the hard way, needed this video 2 weeks ago!

Congratulations on your APODACA picture today Trevor - well deserved!

Fantastic video and picture but it’s also nice seeing how you are changing stuff over the years to make yourself more comfortable on the cold nights

My 2c on guide scope focussing: * get close to actual focus during the day on a distant power pole or tree, mountain top or similar distant object. You can get pretty close to actual infinity focus and not waste precious clear night hours, and figure out if you need extensions beforehand. When night comes you should then only need to fine-tune it with the helical focusser. * at night focus with sharpcap before switching to PHD2 - I find sharpcap's autostretch to do a much better job of showing the stars (esp out-of-focus) than PHD2. I can see stars and focus in Sharpcap with just 0.5s or 0.25s exposures (once I get close) in sharpcap, which really speeds things up as it feels 'live' and not laggy as it is with PHD2. It also has a focus aid based on FWHM to get the focus bang on.

Thanks much for this video. I have a new auto-guider (ZWO 30mm f/4 Mini) and ZWO ASI120MM-MINI camera and the part on focusing was very helpful. I'll be trying them with my new William Optic GS61 on a Skyguider Pro and ASIair Pro as soon as the weather cooperates.

I used same StarField 60mm guide scope, and even better camera ASI290MM, however it had an ugly coma. Some troubleshooting didn't help. However I was able to make 10 min shots with this setup and my EQ6R.

Trevor, you're an astrophotography genius!

Nice image! Tip for that 120mm. Turn the gain down to 10 or 20 in PHD and it will auto select a brighter star with much higher SNR. I found that high gain and it was selecting very faint stars which are of course more influenced by the seeing. My guiding RMS literally halved simply by doing this. CEM25P btw

The eastern veil nebula and the Orion nebula are my favourite nebulas

Hey Trevor! Your videos got me into this hobby recently. I have that same guide camera :). The weather in Ireland has been terrible all year I haven't gotten a clear sky in weeks. I'm using this time to upgrade my pier and build an observatory. Great video that is my favourite nebula :)

ye know Trevor, i never watched this vid before bc the title didn't interest me!? But i just watched it after running dry on "My fix of AstroBackyard" lol. Then I saw this and clicked play! Well it was/is great! Thanks! ( I'm reminded of that old saying..."Never judge a book by it's cover"... ) Wes, Liverpool, UK.

astrophotography and your cinematography skills. awesome sir. your videos inspired me to start astrophotography. love from India.

Great video Trevor, but when calibrating the first time you have to do it at a meridian/equator cross, so that the mount is basically horizontal, then you can so the guide assistant at a object you are going to image👍

Awesome video

Spectacular veil again😊 The new screen in the garage works nice Trevor. Looks more personal then a mugshot pasted in the corner. Only thing is the focus on the screen shifts with you moving in front.

Nice work. I hope you are printing those shots and hanging them up around your home. Those are images to be proud about. Congrats.

Thanks for reviewing the ASI 120mm guide scope. I received mine about 2 months ago after my Starlight Express Lodestar X2's chip failed. Love the ZWO ASI 120's performance; using Maxim DL 6 for guiding with an Orion CT 80 guide scope. I'm going to play around w/PHD 2 but have had great guiding using Maxim. Regardless, a great guide camera and just got my ZWO Pole Master after it being on back order so looking forward to using that; I really liked your review of that as well!

Thanks, this will be very helpful in about 13 years when all of the equipment I ordered comes back in stock :)

Man this is so inspiring. I'd absolutely love get into astrophotography. I just don't have the money at the moment.

The very best of Astrophotography, as usual. Thank you. Rémi

Love the comment about people getting caught up on the technical aspects of astrophotography. But seriously, we gotta get you off APT. Just seeing that UI on your video gives me the heebie-jeebies.

Great video. Good explanation for newby astrophotographers

Hey Trevor! Due to watching your videos, I've been inspired to start star watching. I'm working on getting a celestron skymaster 15×70 Binocular and tripod. I've always wanted to observe the cosmos but thought I would need an expensive setup like your. After learning that I could start off with binoculars I was inspired to go for it!! Thanks!

I think that was one of your best videos. Very well put together.

Great video Trevor like always it's informing and you answer my question about autoguiding and I will get a ASI120.Keep doing you're great job you're so good and yes it was special when you were in your old garage!

Beautiful scope that's one big heavy mount awesome setup

Holy f... amazing work once again Trevor, this image gave me chills

Good discussion. I have same set-up on guide system as yours and had similar focus issues particularly because I travel with my scope to dark sites. I solve it by focusing in the daytime on a mountain or tower or telephone pole. This puts you in the ballpark. Doing it at night is a pain to find bright star areas.

This camera can have alot potential not just for guiding!

To get the most functionality out of PHD2, you should bin the ST4 cables and run USB cable direct from guidescope to laptop, and a USB cable direct from laptop to mount. This will allow PHD2 to know side of pier/where the mount is pointed etc as ST4 will not communicate this. Helps a lot with drift alignment.

"you wanna see that flatline like a dead patient at a hospital." got me so bad lmao

Great job mate. Keep doing what you love!

I don't know why but the veil nebula always gives me a retro vibe with those colours.

Subscriber from India ✌️

I was actually looking to purchase this guide package, your video was posted at the perfect time. Great video Trevor!

Hey Travor, Please send some of your good weather here to London, U.K . The weather here has been cloudy for almost a week, I'll loved to get outside with my Telescope and Starwatcher adventure mount and my Canon 600D camera, let's hope the weather gets better soon, clear skies 🌠

Your content is incredible. Some of the best on RU-vid.

Great video Trevor, I think it's very helpful for people starting out! And what a gorgeous shot of the Eastern Veil... The Cygnus Loop is one of my favorite areas of the night sky.

My first look in my telescope was Jupiter and it was pretty.

ST4 cables are not needed anymore, just connect usb-c and choose your mount instead of "on camera" in phd2. And don't balance your scope on the RA axis perfect or your guiding will be off - at the beginning I did balance my scope perfect and was wondering why my guiding was so bad. Make it quite a bit east heavy (scope or counterweight side heavier depending what is facing east) so there is always tension/weight on your wormgear or belt. For people without a direct view of polaris, the EQ6R pros internal polar alignment routine is quite good and much quicker than drift alignment. Just do a 2 star alignment, then a polar alignment, then again a 2 star alignment and another polar alignment. Most of the time it is spot on (check with phd2 drift alignment tool). As Trevor says don't overvalue the phd2 graph. Depending on your setup a value of under 1.0 rms error has no impact at all because your setups resolution/image scale is not even high enough.

Fabulous image Trevor. Lockdown forced me to push myself and I’ve actually tinkered with PHD2 guiding as well as plate solving with APT, both reasonably successfully. Hopefully soon I’ll get the chance to deploy all this and more out in the field away from the local heavy light pollution. Just need some portable power for my laptop and come the proper darkness of August onwards I’ll be all set. Of course I could go for a ZWO ASIair Pro but I’d need to re-learn a few things! Keep your inspiring videos coming 👍🏼

Great narrative, but since the target auditory is beginner astrophotographers, a 'full setup process' could've included setting up the PHD2 for the first time with this camera (show the wizard), capturing the dark library, and perhaps a few words explaining what helical focuser is and showing it in action.

as always, wonderful pictures, detailed video, great music and tasty cuts :)

Hello Trevor, what a coincidence my ZWO ASI120mm Mini guide camera arrived today; thanks for the useful tips. g

The Canon Ra does a fabulous job doesn't it? Wow. Excellent tutorial on PhD Trevor. Thanks!

Brilliant content as always, Trevor!

Hot DAMN!!! That Veil is gorgeous!

Thanks Trevor for another exciting educational video.keep them coming.

Great vid! Waiting on my new telescope and mount to show up to start my new hobby, watching your videos definitely "encouraged" me to get going on it haha excited to see what you do with the SCT!

I subscribed to you because you are excellent. I love your way of explaining. Your Dog is beautiful and must love when you take out your Telescope,

Great to see you covering some of the basics again using the experience that you've gained. Question (possibly a dumb one): you used the ST4 cable for the guider--is the other end plugged into the handset or the EQ6 autoguide port? Isn't there another way to do it that doesn't involve the ST4 cable? I always get confused on this point. Thanks for all you do.

At a scale of 4" on an affordable consumer mount like an eq6 that graph looks just fine. Alot of people make videos showing off their "flat" line, but its at a scale of 8" or even 16" sometimes. Total error under a minute is great. Now if i had a mount worth 10's of thousands of dollars i might be a bit miffed.

Beautiful finished product Trevor! Veil is such a perfect target for duo narrowband. Would still love to see you dive into pulse guiding/ platesolving and make your life easier down the road.

That's awesome, I only have a small dobsonian

Good job Trevor keep up the good work! Don't let the PHD graph bullies get you down LOL!

I use a weight pole extender on my eq6 that they make for that mount. It gives you about 8 inches more for your weights for those heavier scopes.

Bloody hell - impressive photo.

Thanks for sharing your love and passion for astrophotography. Have you every thought of doing a video on focusing when using narrow band filters?

"You don't want to be stuck out there without the right extension tubes" This is spoken truth.

Hi Trevor, thats again a really interesting quality video and exceptional resulting image! Great job!