malc-c

Peter, I was just trying to simplify things... if you start factoring hours seconds and minutes the poor bloke will get confused - But yes, I probably confused him slightly... This was what I was trying to relate to, that he would need some form of starting point, much the same was as the meridian line is used....

I still feel you need to follow the above advice and read up on celestial coordinates. Declination runs from +90 at the NCP to -90 at the SCP, with 0 degrees being the celestial equator. Right Ascension runs from 0 degrees North, through 90 degrees East to 180 degrees South, and 270 degrees through West. I think you are somehow applying Altitude and Azimuth system to an EQ mount, especially with comments of the DEC axis being above the Polar Axis ??? The mount you are using is an EQ mount so it will have its Azimuth axis tilted over to your latitude so that it is parallel to the Earth's Axis, and thus becomes the Right Ascension Axis Assuming you have perfect polar alignment, so in order to track an object only the RA to counteract the Earth's rotation. The Declination of an object is fixed (other than the planets), and will be XX degrees YY minutes and ZZ seconds either on, above or below the celestial equator which is 00:00:00 degrees declination. The declination is an angular movement, so if a target is 30 degrees above the celestial equator and you want to slew to a target at 20 degrees, then you need to drive the DEC axis NN steps of the stepper motor to move the mount 10 degrees. However you first need to set the starting point so the software you are using has that datum point (which is why all goto mounts do a one, two or three star alignment). Now you could centre a star of known declination and then set the mount to that location and once centred press an alignment set button to zero out the coordinates. However any star on the celestial equator will not always be visible at certain times of the year. You could set the mount to +90 degrees Declination and point the mount at the NCP. But as there is no clear identifying star (Polaris is a few degrees off the NCP so that's not really useful) this can make alignment difficult and can introduce more error than aligning at the celestial equator. Once you have found a suitable and reliable way to set that initial starting point then it's fairly easy to work out how to drive the mount to a given position. Stepper motors have a set number of steps per degree of rotation of their shafts, so if the motor has 10 steps per degree, 3600 steps will give a full rotation of the motor. You then workout (or obtain from the manufacture) the ratio of the gearing for the mount. Lets say that the ratio is 20:1 just to make the math easy, so for the mount to rotate one complete revolution the motor has to run for 20 x 3600 = 72000 steps, which equates to 200 steps per degree the mount is moved. So in the example above, to move 10 degrees the controller needs to send 2000 steps to move the DEC axis. In reality it's a little more complicated as the ratios are not as simple, but hopefully you get the idea.

It was either that or a nice shade of green ! It's been 10 years this spring since I put my mount in the ground, and other than the anodizing fading a little, and a few scuff marks on the black paint the mount hasn't changed much. Can't believe it's coming up 10 years since I started the observatory !! Note that when fitted the pipe was left full length and then cut to the correct height once the southern angles had been worked out, I would advise doing the same. I must admit it will be fun for the next owner to remove

That's a contradiction of terms. Alan was asking about removing both IR filters and using the camera in that basis... you are using a clip filter (and a very expensive one at that) to do the same job as the Badder modification which replaces the canon IR cut filter As you have a filter in the optical path it's quite possible that this is the reason the stars are not bloated. Very nice image by the way 😉

A standard 160mm drain pipe when filled with concrete and rebar would be substantial enough, especially as you are only having 900mm sticking out above ground. If you have the opportunity to use 200m pipe, then given that this would be something you wouldn't really want to "upgrade" use it now - it would futureproof the mount too. You are also spot on with the two plate arrangement - you can then level the top plate and it makes gaining access to any mounting bolts easy. Use aluminium, as steel rusts ! - Oh and use good quality stainless steel nuts and bolts - no rusting You may choose to use thicker ali, plus you can anodise it to give it some protection....

Why try and reinvent the wheel.... there are already lots of existing 3rd party DIY alternatives to commercial products like synscan. I'm no expert, but I don't think there is such a correlation between the two axis. In an ideal world an EQ mount will only need to track in RA. The DEC will stay the same. To track a target, the mount needs to move at the same rotational rate of the Earth but in the opposite direction. So 360 degree / 24 = 15 degree per hour or 0.25 degree per minute. The DEC axis won't need changing as the track of the scope will match the arc the target forms. Something that is 30 degree above the meridian will always be 30 degree above the meridian as the meridian itself is an arc from East to West. The only time you would need to control both RA and DEC axis would be if you were using an ALT / AZ mount (like a Dobsonian) as the "height" of an object will change as the AZ axis is level and not tilted to the latitude of the observer

An edited text from Gary's website - I've underlined the key parts - 450D: In April 2008, I completed a modification of the Canon Digital Rebel XSi (450D) to remove its IR Cut filter. Removal of the filter allows for a great increase in sensitivity to the color red and the H-Alpha wavelength important for deep sky imaging. Instead of installing a clear optical glass to replace the original Canon IR Cut filter as I had done for the 300D modification, I installed a Baader "DSLR Correcting Filter" which is a much milder UV-IR-Cut filter that allows the H-Alpha wavelength to pass for deep sky, but blocks higher infrared wavelengths that cause poor focus and bloated stars with refractor telescopes and camera lenses. This filter still allows the 450D to be used with an infrared pass filter, such as the HOYA R72, to take daytime infrared images with focusing via the live-view feature. Another option is to install a clear glass of equal thickness (0.57mm) of the IR filter to maintain viewfinder focus accuracy and the camera's autofocus. Lifepixel.com sells such a clear optical glass. A third option is to just remove the original Canon IR Cut filter and replace it with nothing, but the autofocus will not work. Since the 450D has the live view focusing feature, using it instead would work well for astro imaging (and daytime images) even if the original IR Cut filter was removed and replaced with nothing.

????????? - No idea... I think the removal of all filters (ie leaving the sensor exposed) mucks up the auto-focus (assuming you intend to do IR photography) and leaves the sensor exposed to dust and grime? Like I said, when I did mine the "in thing" was simply to remove the IR cut filter, and replace the second canon filter with the Badder BFC filter. Naturally if you remove all filters the sensor can see all of the spectrum within its design parameters at 100% transmission levels. I personally can say which is better, I've already explained why I installed the Badder filter

No... it is a tuned IR filter to let IR spectrum and the emission wavelength of Hydrogen Alpha through - The thing is that these days I don't think they still make and sell these filters anymore https://www.baader-planetarium.com/en/services/canon-astro-upgrade-for-all-canon-aps-c-dslr-cameras.html Having said that, a quick google and 365Astronomy list them in stock for around £55 https://www.365astronomy.com/baader-bcf-h-alpha-intensifier-filter-for-canon-7d-40d-50d-60d-400d-450d-500d-550d-600d-650d-1000d-1100d.html

You're paying for the tooling for the cases, PCB design and manufacture and the IP of the developers who coded the hand controller and motorboard firmware... When you consider what's gone in to developing the synscan system, without any consideration of the cost of the legal stuff such a patents and protection of their IP, the cost of testing to insure it complies with the strict regulations of the countries they sell to, and the fact that at the end of the day they, along with the importers and retailers all need to put bread on their tables, the additional cost is IMO reasonable.

Personally, at the time I did mine, it was recommended to replace the IR cut filter with the Badder filter... opinions may have changed. I live in a town, and even with the move from sodium to LED lighting I can still see the benefit of the modification. In my opinion having something covering the CCD means it's dust free, especially as in my case the scope and camera are left coupled together in the observatory. To give you some idea on how my camera performs with the Badder filter, here's a single exposure of the moon. The only processing done is to reduce the image size to suite the forum (in PS CS2 😉 ) And the same image with PS's auto levels applied

These cameras have two IR filters - a full spectrum mod removes both filters and replaces them with a clear filter so you get the full spectrum from beyond IR to beyond UV to whatever range the sensor can detect. I opted for the Badder mod, which replaces the low pass filter with one that still give some filtration. Gary Honis was one of the pioneers in modding these cameras - have a read http://dslrmodifications.com/FullSpectrum/Advantages.html

Well a lot of retailers need to update their descriptions then 😉

Thanks for the additional info. The pro's and cons for a got system have been debated since they first became readily available for the masses. Some people like to use them as a teaching guide to help them become familiar with the sky, others it saves time and effort. The stepper motors also have more precision than the DC ones used in a cheaper dual axis drive, but the dual axis drive could be a compromise, in that once found you can easily let the mount track the object for you. Goto mount have that added ability to allow PC interfacing should you later want to go down that route. One of the biggest issues at the moment is availability... Most suppliers are out of stock of nearly all telescopes, and it could be summer time before new stock arrives, which no doubt will go straight out to fulfill backorders. Back to your original question... for me I would suggest a newtonian scope with as big an aperture as you can afford and store. You can then invest in a decent 3x barlow lens and get acceptable images of the planets, but used without a barlow, get decent bright images / views of DSO's. For me I wanted to image DSO's so opted for a 200P, which with a barlow gave me an 8" scope with a 3000cm focal length. Using a cheap webcam I got some decent images of Jupiter's belts and the GRS. But removed the barlow and equally get nice images of galaxies and nebula. The 150PDS EQ3 pro goto comes in at £620 https://www.rothervalleyoptics.co.uk/skywatcher-explorer-150pds-eq3-pro-goto-telescope.html - It's not shown as out or delayed stock so you may be lucky If you want a goto dob then it seem the 200P flextube is the "smallest" aperture, but is stretching that budget at £778 https://www.rothervalleyoptics.co.uk/skywatcher-skyliner-200p-flex-tube-synscan-goto-dobsonian-telescope.html Naturally if you went old school and did away with the goto, then you could get a lot more scope for your money with the 10" 250Px coming in at around £518 https://www.rothervalleyoptics.co.uk/skywatcher-skyliner-250px-flex-tube-dobsonian-telescope.html Another alternative is a refractor - The 120 Evostar / EQ3 pro goto comes in at £685 https://www.rothervalleyoptics.co.uk/skywatcher-evostar-120-eq3-pro-goto-telescope.html - a 4.47" (120mm) f8.3 would on paper at least be a reasonable balance between planetary and DSO.. How well the optics perform I can say as I never used one to compare. Again, if you did away with the goto, you could go one size larger and get the evostar 150 on an EQ5 for £765 https://www.rothervalleyoptics.co.uk/skywatcher-evostar-150-eq5-telescope.html Other retailers are available and prices may vary... Hope that has given you some food for thought

One thought that comes to mind, and correct me if I'm wrong as I've not had a play with these modern mounts, but when taking an AZ/ALT goto mount and tilting it so the AZ axis now points to Polaris, doesn't the sysnscan screw things up ?. Under a normal operation the firmware running on the handset has been written so that it sends pulses to both AZ and ALT axis in order to track. On an EQ mount only the RA axis receives commands to track. Just to make sure I wasn't spouting a load of BS I did a little research... seems I was right, however SW provide the corrected firmware for the mount, along with additional tools to allow control of the mount https://youtu.be/xJmntIr50lk

Just bear in mind that the dual axis motor upgrade uses DC motors where as the goto upgrade uses precision stepper motors. The latter means finer control for imaging if that is the ultimate goal. If you simply want the scope to track a target once you have manually found it so that the target stays in the field of view of an eyepiece with just the need for the odd correction, then the cheaper dual axis system will be fine.

Care to share what your budget is? - It's no good us recommending alternative mounts or set ups if it's way outside your budget. Is a goto synscan mount important to you Do you intend to try and image through the scope rather than do purely visual observing Do you need portability, or will you be observing from your garden or somewhere specific like a balcony Do you have limited storage space - this would rule out suggesting dobsonian scopes and the like

The bootloader is a small section of code that typically is placed at the top of the memory at the time the microcontroller is programmed. This little bit of code is what the handset talks to when flashing the new firmware (the firmware is the main code that handles the instructions from the handset and converts them into movement of the mount). If the bootloader is corrupted then the only way to resolve that is to reprogram the microcontroller, either with a fresh copy of the bootloader, or with a full image that includes the firmware. I've repaired several Skywatcher motor control boards by reprogramming the PIC Micros on them with the Skywatcher firmware, but I've never tried flashing the firmware of a handset before. The process for flashing the handset firmware can be found here Firmware update - It states a different combination to the buttons you used... maybe this is the issue? - You could try that, and if you are using a USB to serial adaptor or an old PC with a COM port, set it to 19200 baud in the properties via device manager. Hopefully the image file the application loads also has a new bootloader, or you have somehow placed the handset in some form of limbo mode and the bootlaoder is still intact

I to have CS2 installed on Windows 10 - never had an issue with it. It even accepted the astronomy tools plug in ! It suits my level of image tweaking

Just found the article I did for our local astronomy society - I fitted the Ha filter as a replacement Performing major surgery.pdf

Stressful !! I did my 400d - removed both IR filters.... If you have good eyesight and steady hands it's a fairly easy job (assuming the 600d is similar). There are lots of tiny tiny screws, and the thin flexi printed cables don't like movement much. If you do the modification yourself, pick a day where you won't get interrupted, have a really bright light to help, and use plenty of pots for the screws.

There is no one scope fits all. The Nexstar 6 has a focal length and ratio that is twice that of the 150p, making the Nexstar a good choice for planetary work, but not as good for DSO's as the 150P, which is a faster scope, giving brighter images, but not as magnified as the Nexstar. The same target in a Nexstar will seem fainter by comparison. Focal reducers are often used with scopes with higher focal lengths, and barlow lenses are used to double or treble the focal length of shorter scopes, so in someway compromises the shortcomings, but the more glass you pot between your eye or sensor and the target can affect the image. We can't advise you which to get... that will be down to you. Your location, the quality of the skies, the subjects that interest you most etc is personal to you.

You could run an extension lead, but the issue is dampness and dew formation, which with 240v could lead to it tripping the house fuse board, or worse a potential shock when you come to unplug things, hence the suggestion to run low voltage 12v to the mount or use a battery. Use the search function to research polar alignment... there are hundreds of posts on how to do it using the polarscope built into the mount. - saves repeating what has already been written. There are also old but excellent videos on youtube on using EQMOD to position the mount and align polaris in the bubble. And yes... you need deep pockets to get into imaging... but unlike other hobbies after the initial outlay you don't have to add further expense... unless you want to.

Being able to Polar Align on Polaris makes things a lot easier. Personally I would pay the £10 for Sharpcap Pro, and use the built in tool to set the mount up using the guide camera / guidescope. It's a lot easier than peering through the polar scope with the mount set to the polar HA position.... As for the hub... can't say really... I stuck to branded hubs rather than a cheap no name off e-bay. One other thing.. I can't recall if you mentioned how you intend to power the mount... The HEQ5 likes to have a decent 12v supply, capable of delivering 2A with ease. In slewing tests mine draws 1.9 amps with both motors running. It's not really advisable to have mains outside, so running a standard mains extension lead to the mount and plugging in the power supply in the exposed damp cold air is not recommended. Ideally, look for a 13.8v regulated supply rated at 5 amps and then run some nice thick multi-stand cable to a weatherproof box (screwfix / toolstation) and then take the feed to the mount off that. Have a search of the DIY section to see how others have done their power distribution. Or you can look at a powerbank...https://www.rothervalleyoptics.co.uk/telescope-power-supplies.html The SW 7amp hour powerbank is around £50 and should give you a decent nights imaging run

That link was for a 5m EQDIR cable, do you intend to have the PC that far away ? If so then you may need 5m USB cables for the connection to the guide camera and for your main camera (assuming the manual exposure is controlled via USB and not a cable release socket as in the case with my 400D). Most people tend to have one long active USB cable between the PC and the mount, where it connects to something like a 4,5, or 6 port USB hub. Then the EQDIR cable, the USB cable for the guide camera, and the USB cable for the main imaging camera is connected to the hub.