FAQ – Planetary imaging version 1.2, July 2022
So you want to take high-resolution images of the planets? Here is a quick guide that will hopefully answer some of the more common questions with links to key resources, it is by no means complete but is designed to get you started.
1. What telescope do I need?
The choice of Optical Tube Assembly (OTA) doesn’t really matter that much for planetary imaging, as long as it is of good quality. You can use a refractor, Newtonian, Dobsonian, Cassegrain, Schmidt-Cassegrain, Maksutov-Cassegrain, Ritchey-Chrétien, whatever your budget will allow. The key point is that, under excellent conditions, larger aperture OTA’s will produce more detailed images of the planets, so try to get the largest aperture you can comfortably handle and use. OTAs with a diameter of around 6 – 12” are commonly used with good results, but larger OTAs (14"+) can produce spectacular images of the planets when conditions allow.
2. What mount do I need?
You can use an equatorial mount or an AltAz mount for planetary imaging. Equatorial mounts are more difficult to align (if not permanently mounted) but don’t suffer from field rotation that AltAz mounts do. Field rotation can be removed using WinJupos or AutoStakkert after capturing, but for the most part it is not required. A motorized tracking mount is highly recommended as you need to keep the planet in the field of view for at least 3 minutes for best results.
It is possible to use a manual mount (such as a push-to Dobsonian), where you move the scope to a position and the planet drifts across the camera sensor while the camera is operating, then reposition and repeat the operation. This is challenging & a bit tedious, but possible.
Guiding (as used by DSO imagers) is not necessary for planetary imaging, since as long as the planet stays on the sensor during the capture process, the software will take care of the rest. Slight movement across the sensor is actually desirable for planetary imaging. It is also not necessary to take calibration (darks, flats, dark flats or bias) frames for planetary imaging.
3. What camera do I need?
For best results, you need a camera that is specifically designed for planetary imaging. These typically have a small sensor size, low read noise, and the ability to capture frames quickly (hundreds of frames per second). ZWO, QHY & Player One make a number of high quality planetary cameras based upon the Sony chips, and are recognised by all the major capture programs and operating systems. SvBony also produces cheaper versions of some of these cameras based on the same chips (e.g. IMX290). A cooled camera is not necessary for planetary imaging as individual exposures are in the order of milliseconds.
At the time of writing (July 2022), there are a number of one shot colour cameras I would recommend at different price points. Using the ZWO prices as a guide (in US$) these are:
- ASI224MC ($200), Sony IMX224 chip, 3.75 micron pixels, 1.2 megapixels
- ASI585MC / Player One Uranus-C ($399), Sony IMX585, 2.9 micron pixels, 8.29 megapixels
- ASI678MC ($299), Sony IMX678, 2.0 micron pixels, 8.29 megapixels
3.1 Wait, you are recommending a 1 Mega pixel camera? My phone has more than this!
In planetary imaging, the number of pixels is not as important as the sampling from the entire optical train. Since the planets are so small, we need a long focal length to image them and only the on-axis portion of the sensor is used. As an example, at the optimal focal ratio for your scope, the width of Jupiter should take up around as many pixels as your aperture in millimetres (eg a 12"/300mm Newtonian should produce an image of Jupiter about 300 pixels wide. Really.) The ASI485MC mentioned above has a rectangular shaped sensor which is useful for capturing lower-resolution images including the moons when they are far from the planet.
3.2 I am using a manual push-to mount, which camera should I use?
You should be looking at a colour camera with a large sensor size, such as the ASI585MC or ASI178MC (or QHY/Player One equivalent). This will give more time for the planet to cross the sensor and you will obtain more frames with less effort than if you were using a small sensor camera. A DSLR might also be more appropriate in this case.
3.3 But what about monochrome cameras? Aren’t these better than one shot colour cameras?
Mono cameras are capable of producing images of the planets with slightly more resolution than colour cameras in excellent seeing. However, the differences are usually quite small and only recommended for advanced users with larger equipment and consistently good seeing. However, if you are interested in mono cameras then these are recommended (or their QHY or Player One equivalents)
- ASI290MM ($300), Sony IMX290 chip, 2.1 Mega pixels
- ASI178MM ($300), Sony IMX178 chip, 6.4 Mega pixels
- ASI183MM ($700), Sony IMX183 chip, 20 Mega pixels
4. Can I use my old DSLR for planetary imaging?
Yes, but they are not as capable as a dedicated planetary camera. I would only recommend using some Canon DSLRs to record the LiveView stream at 5x zoom directly from the camera to a computer through the USB cable. Only the Canon DSLR system is able to capture an image from the sensor at the necessary 1:1 pixel ratio to be successfully used for planetary imaging. When used correctly, quite high resolution images of the planets can be captured with a Canon DSLR. You need special software to capture this live stream, there is a website that describes this technique here.
In order to connect your DSLR to the telescope, you will need a T-ring (which is specific to your camera type) and T-adapter. The camera simply replaces the eyepiece.
4.1 How about using my mobile phone?
Eyepiece projection (or more strictly “afocal imaging”) can be used for planetary imaging using a mobile phone camera where the lens element cannot be removed. This style of imaging requires a high-quality eyepiece and an adapter to hold the phone in place. Normally this will clamp onto the eyepiece and the position of the phone can be adjusted to line up the lens with the eyepiece. While this method will give you an image, the quality will be significantly lower than what can be achieved with a dedicated planetary camera or Canon DSLR due to the lossy processing algorithms used in the camera to produce the video stream. If possible, choose settings that produce the highest quality video mode at a reduced number of pixels for best results. This approach is generally NOT recommended.
5. What computer do I need?
A high performance laptop is not necessary for the capture phase of planetary imaging, however it would make the processing time shorter. A modern laptop with an i5 processor (or AMD equivalent) with at least 8GB RAM and USB3 ports is sufficient to run the software. More important is to have enough hard disk storage space to hold the enormous video files you will capture. An SSD at least 500 GB in size is highly recommended as each video file will be at least 1 GB in size, typically much more than this (depending upon your framerate and ROI size). An external 4 TB HDD is recommended for long term storage of these files (assuming you plan to keep them).
6. What accessories do I need?
6.1 Barlow lens
The barlow (or tele-extender or PowerMate) may be needed to obtain the correct focal ratio for your system. The rule of thumb for optimal performance is as follows:
- in good seeing, set the focal ratio to 5x the pixel size of the camera
- in excellent seeing, this can be increased to 7x the pixel size of the camera
- in ok-to-fair seeing, this can be decreased to 3x the pixel size of the camera.
Note that the size of the OTA doesn’t affect the optimal focal ratio, however larger apertures will achieve better results as they have better resolving power. There is a mathematical “proof” of this rule (which can and is often debated), however it has been shown the “5x rule” holds for most real world situations. You can find the maths and some discussion about it in the link below.
Therefore, you should use a barlow in your optical train to get close to the required f/num. An as example, the ASI224MC has 3.75 micron pixels, so you should aim to produce a focal ratio of around 5x3.75 = f/18.75. So for the ASI224MC:
- when using a 10” SCT with native focal ratio f/10, use a 2x barlow to give you f/20
- when using a 12” Newtonian with a native focal ratio f/4, use a 5x barlow to give you f/20
- when using a 5” refractor with native focal ratio f/6, use a 3x barlow to give you f/18.
If you have a different camera (such the ASI462MC with 2.9 micron pixels);
- when using a 10” SCT with native focal ratio f/10, use a 1.5x barlow (or unscrew the barlow element from a 2x) to give you f/15
- when using a 12” Newtonian with a native focal ratio f/4, use a 3x barlow plus a spacer to give you around f/15
- when using a 5” refractor with native focal ratio f/6, use a 2x barlow plus a spacer to give you around f/15.
Except for "telecentric" barlows (such as tele-extenders and some PowerMates), barlows don't always provide a fixed magnification and adding a spacer behind (on the camera side of) the barlow can increase the magnification of the image. So if you cannot easily achieve the required focal ratio increase with a single barlow, you would be better to get an underpowered barlow and add some distance between the camera and the barlow. Note that the opposite is also true, if it is difficult to find a 1.5x barlow, then reducing the distance between the barlow and the camera by unscrewing the barlow element and screwing it into the camera nosepiece could give you the required magnification. Tele Vue has a helpful graph that shows this effect on their website.
When you have taken an image of a planet, you can check what focal ratio you are actually capturing at by measuring the width of the planet on the screen in pixels, looking up the actual size of the planet at the time of capture in arcseconds (SkySafari or Stellarium is good source for this), the pixel size of the camera and plugging these into this equation to give you the focal length in mm:
After you know this, simply divide the focal length by the aperture of your scope (in mm) to get the actual focal ratio of your system. This formula came from this website, which has several other useful formulae.
Image scale is also displayed during the measurement phase in Winjupos, allowing the f-ratio to be derived more accurately using another formula from the website just mentioned.
6.2 UV/IR Cut filter (for colour cameras)
The “must have” accessory for colour cameras is a UV/IR-Cut filter (sometimes also called a luminance filter). Most planetary cameras do not come with an IR-Cut filter as standard, and the Sony chips used in planetary cameras are very sensitive to IR which can spoil the colour balance & reduce the potential resolution of your image. IR-Cut filters usually screw into the nosepiece of the camera or barlow. Obviously if you are using a monochrome camera then the R/G/B filters should already filter out the IR component of the spectrum. A combined UV/IR-Cut filter is also perfectly adequate for this purpose, but largely unnecessary as the majority of optical systems and sensors are largely UV-opaque.
6.3 Upgraded finderscope
A good finderscope can make finding the planets much easier. The cheap "red-dot" finder your telescope might have come with is not ideal, it is well worth spending a few dollars on a magnified finderscope. Personally I have found an 8x50 RACI finderscope a delight to use, others prefer a straight through magnified finder while others prefer a finder with an illuminated crosshair for a little more money. A well-aligned 8x50 or 9x60 finderscope will allow you to place Neptune on your sensor.
6.4 Atmospheric Dispersion Corrector
The next accessory on your list is an Atmospheric Dispersion Corrector, or ADC. This device corrects for the dispersion of the light from the planet caused by refraction through the atmosphere. It is more significant at lower angles of elevation (when the planets are below 40 degrees or so), but benefits can still be obtained at higher elevation angles (up to around 60 degrees or so). If the planets peak very high at your location this accessory might be less important to you. Some helpful posts on how to use and align the ADC are below. Remember the planets will vary in elevation throughout the night – they will not always be at peak elevation!
6.5 Electronic focuser
An electronic focuser is a handy accessory to have, it allows you to adjust focus without having to touch the tube or mount. A Crayford style electronic focuser is preferred (and one with a digital readout (DRO) is even better), however the focuser that attaches to the focus knob on an SCT is also helpful. If these are deemed too expensive, then a long hairclip or clothes peg on the focus knob can be used to reduce vibrations.
6.6 Electronic Filter Wheel (for mono imaging)
If you want to use a monochrome camera, an Electronic Filter Wheel (EFW) will be very useful (in addition to the actual colour filters); it can be controlled by the capture software and reduces the time between captures for the different colours. This is where a DRO on your focuser can be very useful if not all filters produce a parfocal image.
Some people use the ASIAIR Pro / Plus (AAP), which is a multipurpose device for controlling and in some cases powering ZWO cameras, EAF, EFW, mounts, DSLRs and dew heaters. It has basic planetary video capture features which are controlled via the companion ASIAIR app running on iOS and Android devices. At present, AAP captures in .avi rather than .ser. The ASIAIR app running on the mobile device can also stack and sharpen partial solar and lunar surface as well as planetary disk. Captured video and stills are stored on the device and can be transferred to a computer for processing.computer for processing.
6.8 Eyepiece projection adapter
If you prefer to use the “eyepiece projection” method (as opposed to the more popular “prime focus” method), then you will need to purchase an adapter or spacer that connects your camera to the eyepiece. The eyepiece works in a similar way to a Barlow lens described in 6.1, by providing a narrower field of view than the native tube. Different power eyepieces will produce a different field of view (FOV), in the same way as different power Barlow lenses will. Most planetary imagers do not use the eyepiece projection method, instead relying on Barlow lenses to produce the correct FOV for their camera.
6.9 Other filters
Other accessories include IR-Pass filters for imaging the planets at IR wavelengths, a methane (CH4) filter for viewing the methane band on Jupiter, UV filters for viewing the clouds on Venus or other planets. Christophe Pellier’s website has a number of very good articles on IR and UV filters and what you can do with them.
IR filters: https://www.planetar...-image-planets/
UV filters: https://www.planetar...ters-for-venus/
6.10 How do I connect all these accessories together?
Most people connect their components together like this:
Eyepiece adapter ---> (focuser) ---> filter (or EFW) ---> barlow ---> (ADC) ---> camera
If you are using a colour camera with a single, fixed filter on an OTA with a natively large f-ratio & low-powered barlow, the following is also common:
Eyepiece adapter ---> (focuser) ---> filter ---> (ADC) ---> Barlow ---> camera.
7. What software do I need?
The two main software packages used for capturing the planets are FireCapture (Windows/Mac/Unix) and SharpCap (Windows only). FireCapture is a dedicated planetary imaging program and is the one I would recommend when starting out. However, if you are familiar with SharpCap already, then it has most of the important features that FireCapture has. If you want to use your Canon DSLR to capture the planets, I would recommend using BackyardEOS for its dedicated planetary imaging section, however this only runs on Windows.
Firecapture website: http://www.firecapture.de/
SharpCap website: https://www.sharpcap.co.uk/
BackyardEOS website: https://www.otelesco.../2-backyardeos/
To stack the video streams, the most commonly used free software is AutoStakkert. At the time of writing, the latest version of AutoStakkert is ver 3.1.4 and it is still under active development. AstroSurface (free) is an all-in-one stacking, sharpening and processing app. To sharpen and process the stacked images, there are a number of software packages out there, including Registax (free), AstraImage (cheap), Astro Photography Tools (cheap) and PixInsight (expensive). For finalizing the images, PhotoShop (moderate cost), Affinity Photo (inexpensive) and GIMP (free) are also used.
There are a number of other software packages that are useful for image processing in certain circumstances including PIPP and WinJupos, both of which are free. To find and identify the planets and their moons in the sky, Stellarium (free) and SkySafari (cheap) are also useful.
8. But I have a Mac or run Linux?
FireCapture has a native Mac or Unix version, so this is highly recommended. Most (if not all) of the image processing software can be run on a Mac using an emulation overlay, however there are few software options available that run natively under the MacOS, such as Firecapture (for capturing video), Lynkeos (for stacking).
Lynkeos website: https://lynkeos.sourceforge.io/
Planetary System Stacker (PSS) is a dedicated planetary stacking app that works for Windows, Mac and Linux, see below for details.
There's a general-purpose Mac specific thread on Cloudy Nights:
9. Do I need to travel to a Dark Sky site to image the planets?
No! You can get perfectly good images of the planets from your suburban backyard, as long as you have a clear view of the sky and don’t have a street light shining right down the barrel of your tube.
9.1. So there are no issues with imaging in the suburbs?
While a dark sky is not required to image the planets, there are other problems that arise when imaging in a built-up urban area, the main one being unstable atmospheric conditions caused by heat haze from being so close to other houses, roads, factories, air-conditioning systems, hot-water units, anything that will lead to heat plumes in the air between you and the target. For this reason, it is best to image the planets well after dark when the earth (and everything on it) has had time to equilibrate with the night air, and the atmosphere is becoming more stable. Try to position your scope away from other houses, their a/c units and hot water systems (as much as practical). Usually grassy areas are better to set up on than dark concrete (which can take longer to cool down).
10. How long should I leave my equipment outside before I start imaging?
It depends – for best results you should wait until your OTA has cooled to around the same temperature as the air around it. For middle to large scopes this can take hours, so it’s best to set up when you can and leave your equipment outside (in the shade) to equilibrate with the surrounds. You can speed up this process by using fans to blow air onto the tube and mirrors (for Newtonians) or into the tube (for SCTs), or even use ice-packs on the outside of the OTA. You might see people cover their tube with Reflectix (foil bubble wrap), Corflute or other foam insulation. The key point here is that the temperature of the tube and its components should approximately match the outside temperature, or in the case of SCTs and refractors, the air inside the tube should be as stable as possible (which is more easily achieved when there are no hot components).
11. How important is collimation?
It is very important to get your collimation right for high resolution planetary imaging. While seeing conditions dominate whether you can get a good result or not, if your collimation is not spot on then you will fail to take full advantage of when the seeing is excellent. Learning how to collimate your scope is an important skill for planetary imaging.
12. Is it better to image the planets when they are high in the sky?
Yes, in general it is better to image the planets when they are higher in elevation compared to when they are nearer the horizon, as there is less atmosphere to image through. Of course, on some nights the seeing will be terrible regardless of elevation and on others it might be great at lower elevations. If imaging at night, the inner planets (especially Mercury) are usually at low elevation angles due to their position close to the Sun, so most of the time you don’t get a choice with them. Imaging Mercury & Venus is generally best done (very carefully, with something blocking the sun from entering the OTA) in daytime.
13. What's the process/workflow for taking images of the planet?
The idea behind imaging the planets is similar to that for Deep Space Object imaging, which can be summarised in block form as:
Capture ---> Quality Sorting ---> Align ---> Stack ---> Sharpen ---> Post Process ---> Publish.
Obviously there's a lot of work in each of these steps, however this is the main idea. While this FAQ will not provide a full description of each of these steps (as there are some great resources on the web already), it will provide some key pointers and links to the online resources that people (including myself) have found useful. For a great introductory set of tutorial videos, I would highly recommend starting with Steve's website "Planetary Imaging - It's Easy (you just have to learn a few things first)".
14. How do I capture the planets?
There are a number of general rules to follow when capturing images of the planets:
- capture video in “high speed” mode, which limits the ADC to 10-bit output (higher bit depths are unnecessary)
- save the data in 8-bit ("raw8") format which trims two more low-end bits (which are largely noise) and makes better use of USB bandwidth
- if using a colour camera, capture in raw (undebayered) format, and let Autostakkert "drizzle debayer" later
- set the shutter speed to match the frame rate required (i.e. for 100 fps, set the shutter speed to 10 ms, set 5 ms for 200 fps, 33ms for 30 fps etc)
- adjust the gain so the peak level (as shown by the level bars on the real-time histogram) is around 50-70% of maximum
- to avoid rotational blurring, recommended capture times per video are (for mono cameras, divide by 3 per colour):
- Mercury/Venus, 5 (good) to 10 (better) minutes
- Mars, 6 minutes at opposition, can increase to 10 minutes as it reduces in apparent size
- Jupiter, 3 minutes
- Saturn, 6 minutes
- Uranus/Neptune, 5 (good) to 10 (better) minutes
- capturing in “ser” format is recommended over avi, as it includes the bayer pattern in the file header and individual timestamps in each frame
- capturing a smaller region of interest reduces file size and can increase framerate. Note that reducing the height (not the width) of the Region of Interest (ROI) can speed up transfer rates. FireCapture's "cutout" box is useful to reduce filesize and keeps the planet in the centre of the frames.
Both Firecapture and SharpCap have detailed User Manuals and tutorial videos, it is highly recommended to watch these (whichever software you decide on).
14.1 How do I find the planets - I have attached my camera and there's nothing on the screen?
Finding the planets can be tricky, especially if you have just aligned your scope using an eyepiece (which most people do). The first thing to remember is that (generally speaking) the focus point for the camera will be very different to that of the eyepiece. So let's say you have the planet visible in the eyepiece and you change over to the camera, all you see is a dark screen with nothing on it. However, the planet is most probably there, just barely visible as a very, very dim out-of-focus donut shape (assuming an SCT). In order to find the planet, ramp up the gain on your imaging software until the donut shape is visible, then start turning the focus knob until it reduces to a tight spot. Then you can turn the gain back down to a more normal level and keep adjusting the focus until the target is focused.
There are at least a few alternatives to this method, which include:
- perform your polar alignment using the camera (rather than the eyepiece)
- keep the focus set for the camera, but align with an eyepiece by looking at out-of-focus donuts
- use a flip mirror, which allows you to use an eyepiece in one configuration of the mirror, and the camera in the other.
14.2 I'm finding it difficult to focus on the planets - what's the best way to set the focus point?
The issue of the best way to focus is a slightly controversial one, with the most experienced imagers doing it by eye on the preview screen, while others borrow a technique from DSO imaging and use a Bahtinov Mask.
If you choose to focus by eye on the screen, there are a couple of functions in the capture software that can aid focusing:
- for Mars, Jupiter and Saturn, use the "Gamma" function in Firecapture (or use FC's screen adjust preview feature) to increase the contrast of the planet by sliding the bar to the left. You may also need to turn the gain up by a notch to brighten the planet so it is visible. For Mars and Jupiter, concentrate on the interfaces between dark and light patches and try to get them as sharp as possible. The edge of the polar cap is a great place on Mars, while on Jupiter we can use white ovals, EZ festoons or the turbulent wake of the GRS. For Saturn, concentrate on the Cassini division in the rings, try to get it as dark and crisp as possible.
- for Uranus and Neptune, use the "Gamma" function again, but slide it towards the right, and try to get the edges of the planet as sharp as possible.
- for Mercury and Venus, look to the edges of the planet and get them as sharp as you can.
If you use this method, don't forget to turn the gamma function off before you start to capture! An advantage of using FireCapture's screen adjust feature is that it does not affect the captured video (i.e. gamma stays at 50).
SharpCap has a similar feature whereby you can adjust the histogram while displaying the planet, move the centre slider up and down to get a more contrasty result.
14.3 How do I keep the planets on the screen - they move about during the capture process?
Since planetary imaging is all about using the scope at a very long focal length, it is normal for the planets to wobble around a bit and your mount may not be able to keep the planet in the middle of the screen. Don't worry, this is not a problem! Simply "nudge" your mount using the hand controller every so often to put the planet back into the middle of the screen. Since you are capturing images of the planets at very high framerates (100, 150, 200 frames per second), it doesn't matter if a few of these frames are blurry as you will have many thousands of good frames to choose from.
14.4 I keep reading about "good seeing" - what is that?
"Seeing" is a term used by astronomers to describe the atmospheric conditions at the time of viewing or imaging the night sky. This can range from Excellent (a stable atmosphere, little to no wind, low jetstream, small/no temperature gradients with elevation, etc.) to "Extremely poor" (the opposite). In excellent conditions extremely fine detail on the planets can be extracted with large telescopes & minimal processing, in extremely poor conditions it's probably not worth setting up.
It is also worth noting that a typical DSO imager (especially with the ubiquitous 80mm APO) can get extremely pleasing results when the seeing is absolutely terrible (by planetary standards). You can get a very acceptable deep sky (aka low-res) image when the scope hasn't really cooled, the collimation might be a bit off and the seeing is in the order of 2-3 arcsec. Planetary imagers need an improvement of an order of magnitude in order to get good planetary images.
Damian Peach has a website showing what different seeing looks like through the telescope and what results he can obtain in these conditions.
15. How do I process the captured video?
This is a complicated section with many different ways to proceed, however here are some general settings for beginners to start with.
- Image Stabilization mode – Planetary
- Quality Estimator – Laplace, noise robust 6, local (AP)
- Reference Frame – Auto size
- Stack Options - try stacking 10%, 25%, 33% and 50% of frames and see which one is best
- Normalise stack to 70% (tick box)
- Sharpened (unticked)
- RGB Align (tick box)
- Save in folders (up to you, I don’t tick this box)
- Drizzle OFF (however for high quality videos, drizzling can be beneficial).
- Close to edge (unticked for most planets, ticked for Saturn)
- Multiscale (tick box)
- Replace (tick box)
- Choose a frame size that gives you about 30 – 50 alignment points when you press “Place AP grid” button.
Autostakkert website: https://www.autostak...om/wp/download/
There is also a great online interview with the creator of AutoStakkert (Emil Kraailkamp) where he discusses the new features coming to AutoStakkert 4, but also covers many of the existing features in version 3.
Astrosurface is an all-in-one planetary processing app. You download the program and it runs inside a folder on your desktop. There are tutorials available that step you through it, but here is a brief rundown.
The first step is to decode your images. This is very much like analyzing your ser or avi in Autostakkert. Click on Detect, and the program will draw a box around the planet.
Once that's done, click Analyze. Astrosuface will analyze your frames and pick the best ones.
Next, stack the frames in the box in the upper right. You can select how many alignment points to use. Click Set.
Finally, click the last box, Stack. Up until now this isn't much different than any other processing program, but wait:
Processing. Here's where the program really shines. These tools are some of the best out of all the programs for ease of use. It's slider based, but once you start using the 2 sliders to deconvolve the image you'll find it very intuitive to use. Once you've finished deconvolving the image, you can spend time in the image processing window. Here you can increase saturation, correct colour balance, colour noise, etc.
Here's the link to the program: This page also includes .pdf tutorials as well as animated movies of how the program works.
15.3 Planetary System Stacker
Planetary System Stacker (PSS) is a dedicated planetary stacking app that works for Windows, Mac and Linux. It includes planetary disk stabilization and wavelets processing. Its home page is here:
The project was announced on Cloudy Nights in this thread
While Registax was originally developed as a planetary stacking program, it is not as good as AutoStakkert and is normally only used these days for post-stacking adjustments. To use it, drag your stacked image to the main window and start changing the wavelet settings until you get something you like. The first three sliders enhance the finer detail, the latter 3 are for coarser detail. People have completely different views on how to use Registax, personally I prefer to Linear unlinked wavelets and adjust the Denoise and Sharpen levels for the different layers until I find something I like. Others use different settings, it’s completely up to you. The “best” settings are up to your personal tastes and are particular to your equipment, which is why it’s difficult to recommend any particular sharpening settings.
Registax has a range of other useful tools such as the "RGB Balance" tool for correcting the colour cast of the original video, RGB Alignment which can be useful for channel alignment. There are a number of tutorials on how best to use Registax (see recommended reading links below).
Registax website: http://www.astronomi...x/download.html
AstraImage has a range of sharpening routines, including wavelets, deconvolution (which can be very useful on the planets) and traditional sharpening methods, and may be easier to understand. It also offers a range of stretching and colour balancing routines. It can also be used to combine individually captured R,G,B frames.
Astra Image website: https://www.phasespace.com.au/
PIPP has a number of tools which may be of use to the planetary imager. It is very good for removing video frames that have been corrupted during the capture process or contains frames where the planet has drifted off the sensor, centering the planet, creating animated gif files, debayering the original raw video (not recommended), plus a number of other features.
PIPP website: https://sites.google...site/astropipp/
WinJupos has a number of useful features for experienced users, from removing planetary and field rotation from video files, combining R, G & B images into a single image, derotating colour and R/G/B image files for stacking over longer time periods without introducing rotational blurring, ephemeris calculations of the planets and their moons and other tools.
WinJupos download: http://jupos.org/gh/download.htm
16. How do I get the correct colour balance for my camera?
Unfortunately, there is a long and detailed answer for this question, and even then it’s not perfect. I spent a long time imaging Macbeth colour charts under D50 lighting conditions, tried to take into account the effects of planet elevation, creating colour correction matrices, skylight removal etc. and learnt a lot in the process without getting a good answer.
For the moment, and especially for people who are colour blind, the best advice is to use the recommended white balance setting for your colour camera (which you should be able to find on the manufacturer’s website) and use Registax’s “RGB Balance/Auto Balance” tool on Jupiter to find the appropriate colour corrections for your camera. Jupiter is preferred as it has the most even colour spectrum of all the planets, Saturn has more of a greenish/yellow hue, while Mars, Uranus and Neptune have obvious colour casts and so the “Auto Balance” tool won’t work on them.
Once you have the colour correction values from Registax for Jupiter, you can use these values on the other planets (after all, the camera settings haven’t changed) assuming that the elevation of the other planet is similar to Jupiter.
Of course, you can just adjust the colour balance settings to suit yourself and how you would like the planets to look.
NASA’s “Overview of the planets” is possibly one of the better references out there showing the colours of the planets, which you can find here.
17. What can I achieve with my equipment?
What you are able to achieve will depend a lot on the atmospheric seeing at the time, the elevation of the planets, how well you have collimated your OTA, your capturing and processing skill etc. Search the forum for posts containing images from others with similar equipment to yours, look at the photo galleries or search external websites such as AstroBin.
The Cloudy Nights forum has a number of "small bore" threads for imagers using a 6" diameter aperture or less
For 8" apertures, some users have posted their results here
For larger apertures, simply use the search function in the forum for the aperture you want.
18. Any other recommended reading/viewing?
Absolutely! Here are some of the websites and resources I have found useful over the years.
For beginners who have never imaged the planets before, Steve’s tutorial videos are excellent and cover the basics of imaging together with descriptions of how to use key software.
For the nitty-gritty and ins and outs of many of the features found within FireCapture, please refer to Martin's really informative article:
For advanced techniques and tutorial workflows, Darryl has an amazing website full of information and excellent images.
To read about using a Canon DSLR for the planets, see Jerry Lodriguss’ website here.
To get Christophe Pellier's excellent book on planetary imaging techniques and other great information on his website, see here.
Damian Peach has a DVD which covers high resolution planetary photography.
To watch me capture and process Jupiter, Saturn and Neptune with a mid-sized (9.25" SCT) scope on a night of good seeing with my local astro club, click here.
The Cloudy Nights planetary imaging forum probably has the answer to anything not covered here – just search it or create a new topic!