I ultimately switched from the once-popular Philips ToUcam 740K to ZWO’s ASI120MM planetary camera. This was after reading many favorable reviews and viewing a plethora of stunning images created by the ASI120MM. During my second night out with this camera, I understood it would significantly improve my imaging results. On my laptop screen, the detail of Jupiter’s cloud belts and the sharpness of the Great Red Spot were considerably greater than I had ever seen previously.
ZWO ASI120MM Review & Tutorial:
Best Buying Tips for Astronomy Telescope
Urban Astrophotography This post contains a review of the ZWO ASI120MM camera, as well as basic instructions on how I captured Jupiter’s video and processed it into a detailed composite picture in Registax and PhotoShop. All of this is based on my second night out with the camera, so as I use it more, my abilities should improve.
The image below compares my greatest work on Jupiter with the ToUcam Pro 740K (from 2005) to my second imaging session with the ZWO ASI120MM. I recognize there are more variables at work than simply various cameras. For example, my 2005 telescope was an 8′′ Celestron SCT, and my current scope is a 9.25′′ Celestron SCT. There might have been changes in the sky conditions and Jupiter’s proximity during the imaging sessions. Nonetheless, the quantity of information I acquired from each camera is impressive. This is a true tribute to imaging gadget improvements.
Urban Astrophotography: ZWO’s ASI120MM Details
List some of the main features and specs.
| Specifications / Features |
|---|
| Sensor (monochrome): 1/3″ CMOS MT9M034 |
| Resolution: 1.2 Mega Pixels 1280×960 |
| Pixel Size: 3.75 µm |
| Exposure Range: 64µs-1000s (62 millionths of a second – 16.7 minutes) |
| Interface: USB 2.0 |
| Dimension: 62mm X 28mm |
| Weight: 100 grams |
| Anti-reflective coating on sensor protection window |
| Full aluminum housing with standard 2″ interface |
| Integrated ST4 auto guider port allows the ASI120MM to be used as an autoguiding camera |
| Wide exposure range allows the camera to be used for planets, Moon, Sun, and deep space objects |
| Can be used as an all-sky camera with the 150º wide angle lens attachment that is included |
| 35 FPS at full resolution of 1280 X 960 / 215 FPS at the lowest resolution of 320 x 240 |
| Threaded screw ports on the back housing for installing the thermoelectric cooler |
| Supported Resolutions |
| 1280 X 960 @ 35 FPS 1280 X 720 @ 46 FPS 1280 X 600 @ 55 FPS 1280 X 400 @ 80FPS 960 X 960 @ 46 FPS 1024 X 768 @ 54 FPS 1024 X 600 @ 69 FPS 1024 X 400 @ 101 FPS 800 X 800 @ 66 FPS 800 X 640 @ 82 FPS 800 X 512 @ 102 FPS 800 X 400 @ 108 FPS 800 X 320 @ 158 FPS 640 X 560 @ 98 FPS 640 X 480 @ 113 FPS 512 X 440 @ 123 FPS 512 X 400 @ 135 FPS 480 X 320 @ 165 FPS 320 X 240 @ 215 FPS 2X2Bin: 640 X 480 @ 35 FPS |
Urban Astrophotography:Equipment Use
Here is all of the main equipment I used to image Jupiter.
- ZWO ASI120MM Camera
- ZWO Color Filter Wheel
- ZWO LRGB Filter Set
- Orion 12.5mm Illuminated Reticule Eyepiece
- Celestron 9.25″ on CGEM
- Zhumell SCT Dual Speed Focuser
- TeleVue 2.5x Powermate 1-1/4 Inch
- Rigel QuikFinder Compact Reflex Site
Urban Astrophotography: Basic Method for Capturing Jupiter with ZWO’s ASI120MM
Here are the general procedures I followed to photograph Jupiter. A 9.25′′ Celestron SCT on a CGEM mount was utilized.
- First, I installed the ASI120MM and adjusted my optical tube. To achieve ideal balance, the counterweights and optical tube location in the saddle were adjusted. This reduces stress on the mount’s gears when tracking and enables the scope to operate smoothly.
- I then removed the ASI120MM and replaced it with an Orion 12mm Illuminated reticule eyepiece, doing a proper drift alignment. This is necessary to maintain the planet in the field of vision (i.e. on the computer screen) while filming it.
- After the drift alignment, I collimated the SCT. When viewing the planets, optical alignment is critical. I began by installing the ASI120MM in order to observe the defocused star on the screen (through Firecapture software). More to come on this later). I fiddled with the secondary mirror’s three adjustment screws until the shadow was as centered as I could get it. Then I took out the ASI120MM and replaced it with a 25mm eyepiece to fine-tune it. The eyepiece allowed for a clearer view of the defocused star. I’ll probably simply use the eyepiece next time.
- I skipped goto since Jupiter is so bright and simple to locate. I swung the telescope around to Jupiter and centered it in the eyepiece. I removed the eyepiece and placed the ASI120MM / color filter wheel into the eyepiece holder after it was centered.
- It was now time to concentrate. Jupiter was out of focus, so I used the SCT focusing knob to bring it closer. Because this causes visual displacement, I have to continuously re-centering Jupiter after making minor changes. However, I was able to utilize a Zhumell SCT Dual Speed Focuser, which is useful for precise adjustments. Furthermore, since it had zero image shift, there was no need to re-center Jupiter after focusing. I spent A LOT of time attempting to get the focus just right.
- It was now time to take some footage when I had Jupiter focused! This was accomplished using the FireCapture software, which is a wonderful tool with many capabilities.
- Because the ASI120MM is a monochrome camera (rather than a color camera), films must be recorded using Red, Green, and Blue (RGB) color filters. The movies of each color are eventually merged to create a color picture. More on this in the next section on processing. You pick the filter (from the drop-down menu) for the color you want to picture via using FireCapture. This was the very first set I made in FireCapture.
- I then chose the red channel’s resolution, gain, exposure time (Exp. ms), and gamma. Then I chose a recording duration of 60 seconds for the video. Because Jupiter has a short rotating period, the entire duration (for capturing all three color channels) should not exceed three minutes. As a result, I chose 60-second films for each color channel. I shot numerous movies of Jupiter with various settings to discover which combinations produced the greatest results. The parameters for the movies (of each color channel) that were utilized for my finest shot from that night are shown below. Because I didn’t have much expertise with the camera, they aren’t always the greatest settings. During the wavelet processing in Registax, I discovered that the gain for the green channel should have been larger. It gave me a horrible “onion ring” effect that I couldn’t get rid of. The amount of information I could bring out in the green channel was restricted as a result. According to what I’ve read, the gain should be closer to 50.
| Red | Green | Blue | |
| Resolution | 512 X 440 | 512 X 440 | 512 X 440 |
| Gain | 41 | 19 | 58 |
| Exposure Time (ms) | 13.65 | 12.49 | 5.0 |
| FPS | 72 | 79 | 111 |
| Gamma | 26 | 60 | 52 |
| Video Duration (sec) | 60 | 60 | 60 |
- It was now time to record the AVI video. I made sure the red filter was chosen on the color filter wheel and re-centered Jupiter in the computer screen’s field of view. Then I shot a 60-second video. This procedure was carried out again for the green and blue filters.
I used this approach to capture the movies using the ASI120MM. It was thrilling to see Jupiter so clearly on the screen! It helped that the visibility was better than usual. The stars were hardly sparkling that night, indicating a relatively steady environment. I recall thinking that I should make the most of the clear sky. Things were difficult to stow away for the night. In fact, I remained up until 4:00 a.m. filming the session’s final video!
Urban Astrophotography: Basic Processing Method
The AVIs were processed in Registax 6 and subsequently in PhotoShop. Fortunately, I discovered a wonderful video instruction provided by David Rankin of Rankin Studio for thorough Jupiter processing. With the ASI120mm, David captured some stunning shots of Jupiter. For processing Jupiter in Registax and PhotoShop, I roughly followed the video below.
Conclusion: Urban Astrophotography ASI120MM
I’m quite thrilled about the ASI120MM’s potential! Other images using this camera continue to produce amazing work, which I admire. I realize I need more practice to polish my techniques, but my objective is to make photographs that are comparable to the work of others. Based on my second session with the camera, I know it’s doable. I want to share my experience as I go along and provide a more comprehensive evaluation at some time. I hope you found this post informative, and please leave your thoughts in the comments area below. We hope you have enjoyed this Urban Astrophotography article.
I ultimately switched from the once-popular Philips ToUcam 740K to ZWO’s ASI120MM planetary camera. This was after reading many favorable reviews and viewing a plethora of stunning images created by the ASI120MM. During my second night out with this camera, I understood it would significantly improve my imaging results. On my laptop screen, the detail of Jupiter’s cloud belts and the sharpness of the Great Red Spot were considerably greater than I had ever seen previously.
ZWO ASI120MM Review & Tutorial:
Best Buying Tips for Astronomy Telescope
Urban Astrophotography This post contains a review of the ZWO ASI120MM camera, as well as basic instructions on how I captured Jupiter’s video and processed it into a detailed composite picture in Registax and PhotoShop. All of this is based on my second night out with the camera, so as I use it more, my abilities should improve.
The image below compares my greatest work on Jupiter with the ToUcam Pro 740K (from 2005) to my second imaging session with the ZWO ASI120MM. I recognize there are more variables at work than simply various cameras. For example, my 2005 telescope was an 8′′ Celestron SCT, and my current scope is a 9.25′′ Celestron SCT. There might have been changes in the sky conditions and Jupiter’s proximity during the imaging sessions. Nonetheless, the quantity of information I acquired from each camera is impressive. This is a true tribute to imaging gadget improvements.
Urban Astrophotography: ZWO’s ASI120MM Details
List some of the main features and specs.
| Specifications / Features |
|---|
| Sensor (monochrome): 1/3″ CMOS MT9M034 |
| Resolution: 1.2 Mega Pixels 1280×960 |
| Pixel Size: 3.75 µm |
| Exposure Range: 64µs-1000s (62 millionths of a second – 16.7 minutes) |
| Interface: USB 2.0 |
| Dimension: 62mm X 28mm |
| Weight: 100 grams |
| Anti-reflective coating on sensor protection window |
| Full aluminum housing with standard 2″ interface |
| Integrated ST4 auto guider port allows the ASI120MM to be used as an autoguiding camera |
| Wide exposure range allows the camera to be used for planets, Moon, Sun, and deep space objects |
| Can be used as an all-sky camera with the 150º wide angle lens attachment that is included |
| 35 FPS at full resolution of 1280 X 960 / 215 FPS at the lowest resolution of 320 x 240 |
| Threaded screw ports on the back housing for installing the thermoelectric cooler |
| Supported Resolutions |
| 1280 X 960 @ 35 FPS 1280 X 720 @ 46 FPS 1280 X 600 @ 55 FPS 1280 X 400 @ 80FPS 960 X 960 @ 46 FPS 1024 X 768 @ 54 FPS 1024 X 600 @ 69 FPS 1024 X 400 @ 101 FPS 800 X 800 @ 66 FPS 800 X 640 @ 82 FPS 800 X 512 @ 102 FPS 800 X 400 @ 108 FPS 800 X 320 @ 158 FPS 640 X 560 @ 98 FPS 640 X 480 @ 113 FPS 512 X 440 @ 123 FPS 512 X 400 @ 135 FPS 480 X 320 @ 165 FPS 320 X 240 @ 215 FPS 2X2Bin: 640 X 480 @ 35 FPS |
Urban Astrophotography:Equipment Use
Here is all of the main equipment I used to image Jupiter.
- ZWO ASI120MM Camera
- ZWO Color Filter Wheel
- ZWO LRGB Filter Set
- Orion 12.5mm Illuminated Reticule Eyepiece
- Celestron 9.25″ on CGEM
- Zhumell SCT Dual Speed Focuser
- TeleVue 2.5x Powermate 1-1/4 Inch
- Rigel QuikFinder Compact Reflex Site
Urban Astrophotography: Basic Method for Capturing Jupiter with ZWO’s ASI120MM
Here are the general procedures I followed to photograph Jupiter. A 9.25′′ Celestron SCT on a CGEM mount was utilized.
- First, I installed the ASI120MM and adjusted my optical tube. To achieve ideal balance, the counterweights and optical tube location in the saddle were adjusted. This reduces stress on the mount’s gears when tracking and enables the scope to operate smoothly.
- I then removed the ASI120MM and replaced it with an Orion 12mm Illuminated reticule eyepiece, doing a proper drift alignment. This is necessary to maintain the planet in the field of vision (i.e. on the computer screen) while filming it.
- After the drift alignment, I collimated the SCT. When viewing the planets, optical alignment is critical. I began by installing the ASI120MM in order to observe the defocused star on the screen (through Firecapture software). More to come on this later). I fiddled with the secondary mirror’s three adjustment screws until the shadow was as centered as I could get it. Then I took out the ASI120MM and replaced it with a 25mm eyepiece to fine-tune it. The eyepiece allowed for a clearer view of the defocused star. I’ll probably simply use the eyepiece next time.
- I skipped goto since Jupiter is so bright and simple to locate. I swung the telescope around to Jupiter and centered it in the eyepiece. I removed the eyepiece and placed the ASI120MM / color filter wheel into the eyepiece holder after it was centered.
- It was now time to concentrate. Jupiter was out of focus, so I used the SCT focusing knob to bring it closer. Because this causes visual displacement, I have to continuously re-centering Jupiter after making minor changes. However, I was able to utilize a Zhumell SCT Dual Speed Focuser, which is useful for precise adjustments. Furthermore, since it had zero image shift, there was no need to re-center Jupiter after focusing. I spent A LOT of time attempting to get the focus just right.
- It was now time to take some footage when I had Jupiter focused! This was accomplished using the FireCapture software, which is a wonderful tool with many capabilities.
- Because the ASI120MM is a monochrome camera (rather than a color camera), films must be recorded using Red, Green, and Blue (RGB) color filters. The movies of each color are eventually merged to create a color picture. More on this in the next section on processing. You pick the filter (from the drop-down menu) for the color you want to picture via using FireCapture. This was the very first set I made in FireCapture.
- I then chose the red channel’s resolution, gain, exposure time (Exp. ms), and gamma. Then I chose a recording duration of 60 seconds for the video. Because Jupiter has a short rotating period, the entire duration (for capturing all three color channels) should not exceed three minutes. As a result, I chose 60-second films for each color channel. I shot numerous movies of Jupiter with various settings to discover which combinations produced the greatest results. The parameters for the movies (of each color channel) that were utilized for my finest shot from that night are shown below. Because I didn’t have much expertise with the camera, they aren’t always the greatest settings. During the wavelet processing in Registax, I discovered that the gain for the green channel should have been larger. It gave me a horrible “onion ring” effect that I couldn’t get rid of. The amount of information I could bring out in the green channel was restricted as a result. According to what I’ve read, the gain should be closer to 50.
| Red | Green | Blue | |
| Resolution | 512 X 440 | 512 X 440 | 512 X 440 |
| Gain | 41 | 19 | 58 |
| Exposure Time (ms) | 13.65 | 12.49 | 5.0 |
| FPS | 72 | 79 | 111 |
| Gamma | 26 | 60 | 52 |
| Video Duration (sec) | 60 | 60 | 60 |
- It was now time to record the AVI video. I made sure the red filter was chosen on the color filter wheel and re-centered Jupiter in the computer screen’s field of view. Then I shot a 60-second video. This procedure was carried out again for the green and blue filters.
I used this approach to capture the movies using the ASI120MM. It was thrilling to see Jupiter so clearly on the screen! It helped that the visibility was better than usual. The stars were hardly sparkling that night, indicating a relatively steady environment. I recall thinking that I should make the most of the clear sky. Things were difficult to stow away for the night. In fact, I remained up until 4:00 a.m. filming the session’s final video!
Urban Astrophotography: Basic Processing Method
The AVIs were processed in Registax 6 and subsequently in PhotoShop. Fortunately, I discovered a wonderful video instruction provided by David Rankin of Rankin Studio for thorough Jupiter processing. With the ASI120mm, David captured some stunning shots of Jupiter. For processing Jupiter in Registax and PhotoShop, I roughly followed the video below.
