jefrs

If you are considering 4/3 sensors then you might consider getting a Lumix G7 which may go for as little as £200 used, if you don't want to spring £1,000. Pixel size is more important than pixel count in low light. The 16MP sensor has 3.75µ pixels. The Panasonic designed Live-MOS is biased to sweep stray electrons off, unlike Sony CMOS sensors. And it is mounted on a heat sink to keep the temperature stable. The powerful processor has features to further reduce noise as it is designed to shoot movie indefinitely without overheating. Shutter speed down to 1 minute and built in intervalometer. ASCOM drivers are available.

There is the word 'stiction' that aptly describes the problem, yes it is a real word for a real problem - "the friction which tends to prevent stationary surfaces from being set in motion"

Break it down to first principles. You have OTA focal length divided by eyepiece focal length giving the magnification of the telescope. Then your compact will add some magnification factor. For a camera that is the focal length of the lens (not full frame equivalent) divided by the sensor diagonal, aka image circle diameter. Multiply them together. Personally I have never managed to get a compact camera to focus on the eyepiece image, I'm told it has to be set at infinity.

Simple answer (I hope) is divide focal length by the image diameter circle (the diagonal) of the camera sensor. Full frame is 43.3mm and this is the proper length of a prime lens to give 1:1 image although we normally use 50mm or 45mm. For micro four thirds the image circle diameter is 21.6mm so its 'prime' lens is 20-25mm thereabouts, and APS is somewhat variable, nominal 35mm. A typical guide camera might be a 1.2/3 sensor of 7.66mm diagonal. These give the equivalent eyepiece focal lengths when used on prime focus. Magnification is OTA focal length divided by eyepiece focal length. A common misconception is that a larger sensor will see more light than a small one. Both see all the light gathered through the lens/OTA iris (or aperture if closed down). The sensor is at the image focal point and sees all the light. A 130mm reflector is 130mm iris. If 650mm focal length then 650/130 = f/5.

Something I'm always trying to get my head around too. Also complicated by the eyepiece because they can vary in field of view as well as focal length, obviously a long eyepiece will give you a wider FoV than a short one. A camera will also change the FoV, sensor size (crop factor), whether on prime focus or eyepiece projector. This calculator may help https://astronomy.tools/calculators/field_of_view/

The SLT mounts are not strong but with some proper servicing can support and move heavier weights than they were designed for. The bearings need cleaning and a good grease like Castrol used and then set up so they rotate smoothly with a very small end float. If set too tight they bind. The Stifnuts are poor, use Loctite, or they adjust themselves. The Alt clutch can be tightened but must still clutch. The motors like some attention, the muck they put in the gearboxes is not good. Plastic cogs need silicone grease, on the teeth not in a pool on the case floor. The gearboxes are like repairing a clock, and reassembly is a metal puzzle, so if you're not confident, leave it alone. The motors seem to like a drop of Servisol Super 10, an electrical lube. The drive cog onto the platen does need a small amount of play, not forcing the two cogs tight together as it is doubtful the platen is perfectly circular; this does mean some backlash has to be tolerated. The tripod can be adequately braced to reduce vibration with some bungee cord around the legs under the tray.

You will find various illuminator adapters here - http://www.astrokraken.fr/accessories-for-skywatcher-star-adventurer-mount-a184487612 ça plane pour moi I don't have a 3D printer and unlikely to get one. A lens hood can be simply made for the illuminator from a black plastic 35mm film can.

Yes! Once I got the camera refocused it's quite amazing. I set up Thursday night 07/05/20. Of course by the time it dot dark there was solid high thin cloud. I could just visually see Arcturus but little else. So I experimented. There's a LED street lamp over our back room before our patios. Despite that and the cloud and high hedge and fence it still did an Auto Align in under a minute. Adding a star to the calibration makes it want to do another Auto Align. So we did that three or four times. Despite only seeing a few stars, now focused, it competed successfully every time, quickly too. I cannot bend down to use the red dot without pain. Thank you once again.

An older thread but a good one. My StarSense was not seeing stars. I have a lot of light pollution, LED street lamps. Auto align kept failing. I read this thread and spent the night adjusting the StarSense camera focus as described above - thank you people. I found the focus point to be quite critical. I found the focus point between 15 and 24 half turns out and then narrowed it down to to around number 20. Meaning these cameras are not all the same. I then started going in quarter turns in and out and then 1/8 turns until I got maximum star count. Whereupon I lost count of turns and simply went back and forth, I had marked the focus housing. Seeing conditions were variable so I was getting between say 65 and 87 stars at the same place on repeats. Tightening the lock ring moved the focus so the last adjustments were made with the ring locked each time. As I got near to optimum focus the StarSense would 'solve' and complete alignment, which had to be blown away and resume the Manual Align. Once completed I got Auto Align to run complete successfully in about one minute. Quite amazing considering the street lighting, houses and trees in the way. Finding a target is not spot-on but it is nearby. Once again thank you to everyone who posted on this thread - if StarSense Auto Align is not solving, refocus the camera even though it is long winded and boring. I actually had more problems with the dog prancing about and trying to eat large planter pots, which makes a change from destroying lens bags and my gloves.

Using two cables to the computer may well be true with the older Hand Controller and the 'Celestron Programming Cable' with USB/Serial adaptor. The instructions seem to have been written for this older system (pic). With the USB Starsense HC the data is fed through to the camera on the RJ12 cable. I did a little experiment when I had to replace the motor board (which has its own update process) - I updated the camera with the NexStar+ Telcon serial HC attached, this did require the camera USB cable to be used, all devices were updated. The updates are reinstalled if they are already the latest ones. Then repeated with the USB StarSense HC, with one USB cable, and again with two USB cables. With one USB cable to the StarSense HC all devices were seen and updated. One or two USB cables made no difference. You can observe the updating in progress on the CFM - latest updates are reinstalled. fyi the supplied camera to mount RJ12 cable is far too long, a 50cm RJ12 cable is adequate (usual online vendors)

Typing correction fluid (white paint in a pen) or Sharpie Silver make good night-visible marks for alignment and switches etc against dark/black surfaces. Both can be cleaned off if desired.

Celestron mount with StarSense AutoAlign USB handset on Windows 10. The StartSense Camera does not need to be connected to the computer by its USB, indeed the computer and CFM will not see it. I do not know why the camera has an USB port, the computer does not recognise it. If you connect the handset by USB before turning on the telescope, the handset will light up but you will not connect to CFM. Connect Camera and handset to the telescope in usual manner, switch on whilst holding down button 7 and the Celestron key together so handset shows 'BOOTLOADER', then connect handset USB to computer. Start CFM, it should now see both handset and camera, in the info box. Wait for its preamble to complete then hit 'update'. Go and have a cuppa whilst it does its thing. Switch off telescope and disconnect from computer. Sorted.

I have acquired a number of old camera lenses over the years and adapted to modern digital cameras. However long ones can also be adapted as telescopes. The M42 lens thread is M42x1mm, as used by Praktica et al. When we speak of a camera lens with a M42 thread, this is the one it will have. The T2 (or T) thread we are familiar with on telescopes is the M42x0.75mm, also known as the Taisei (the inventor) or Tamron thread. Both are ISO-metric threads, they are not interchangeable. M42x1 to DSLR camera adaptors are readily available, these lenses were mostly for 35mm compact film SLR thus back focus should accommodate a mirror box however using a shorter adaptor will increase focus-turn range at infinity (some old lenses are not right at infinity on full turn). To adapt a M42 camera lens as a telescope to astro cameras or eyepieces we need to convert to T2. The TS-Optics Adapter M42x1 female to T2 male aka "russian adaptor" is available from 365 Astronomy in the UK without the silly shipping charges from abroad. https://www.365astronomy.com/TS-M42x1-female-to-T2-male-adapter-for-Russian-Objectives.html We may need to further reduce from T2 to C mount (CCTV camera) but these adaptors are more readily available.

An altazimuth mount has to be horizontal so it knows where zero degrees 'horizon' is. Use a spirit level but it doesn't have to be perfect. The mount has to be levelled anyway so I have a little spirit level in the toy set. You have to take the lens cap off (always a good one) The StarSense AutoAlign has to go through a rigmarole first calibration set up - read the book, there are some how-to on YouTube. Read The Book https://s3.amazonaws.com/celestron-site-support-files/support_files/94005_starsense_autoalign_manual_february2016.pdf Watch YouTube The set up "Calibrate On A Star" is important and one-off. After that it can do its normal automatic alignment dance Yes the clock and latitude and longitude has to be correct. I use a phone app (PS Align Pro) and it's GPS for time, lat & long (the app is for an Equatorial mount really, does the other thing). Lat & long only needs to be set once for each location, time and date every time. I only use GMT (UCT). Zulu time saves a lot of confusion. No idea why merikans can't use international date format, or metric screws, like something out of the ark. Do they know NASA is all-metric after they nearly mucked up landing on the moon? Have fun.

The 130 SLT has a clutch only on the OTA up and down, the rotate does not have a clutch at all and is fixed firmly with locators, pegs in the bottom and a key-way on the axis bolt; its bearing can be adjusted to reduce wobble. The big gear wheel is screwed to the underside by two small screws which need to be quite tight (they're not really man enough for the job), turning by hand may loosen then or strip them out. Turning the rotate by hand may damage the gears. The OTA clutch can be adjusted by the nut under the clamp. Pull the OTA clamp hand screw out to access the nut. I have the clamp hand knob at the top where I can get at it and a hole drilled through for a screwdriver shaft to nip it up; I have arthritis. Old thread but I've just had it apart again to service. It needed fresh grease because the old stuff was as much use as soap. Everything tightened up snug; less play, less backlash.

Thank you everyone. Yes by "Digital Camera" I mean my various micro 4/3, being mirrorless are not "SLR" but can swap lenses. Back focus is a bit different but results are very good once that is understood and they're mounted properly. Initially the lack of a mirror box meant they wanted to sit practically inside the OTA; eyepiece projection works. Lack of sensor noise on the GH4 is excellent as being developed for video the sensor is mounted on a heat sink and the LMOS is biased to sweep stray electrons off it. Likewise the G7 but the E-M5ii has a bit more noise at high ISO and likes to turn magenta with long videos as its sensor cannot be cooled, good shooting controls on it though, and a USB tether program. The crop size with a long lens means that some of my long lenses make effective telescopes in their own right; the 800mm mirror lens becomes FF equivalent to 1600mm and there is a x2 teleconverter for it. The Bigma 50-500, well you can work it out. Wide angle I can go down to 7mm. They can go on the Star-Adventurer. My telescope is a Celestron 130SLT, Barlow, various eyepieces. I do have DSS but it's been a few year since I've been able to use the telescope, things happen like that. I was hoping software applications had moved on a bit. APP looks good but it's £150 to purchase and I'm on a pension, hmm ... Forgive me, I may be old and dim, but I cannot find any "Timeline Feature" in Photoshop Elements 14 (or 12). It may be there if it is called something else now. I do also have the 'Premiere Elements 14' which is the video app. I do not use 'Organiser' as I use a less intrusive database for that job.

Possible silly question. Could be a greek parliament. What stacking software to use with digital camera astro photos (and video/time lapse), in Windows 10. Looking for effective and with ease of use. Some of the software apps I've looked at are pretty old now and rather clunky.

Norton Star Atlas and Reference Handbook

This can be programmed into the handset Settings menu, process is in the manual, advanced settings, as is cord wrap limit to 360°, and many other things. Slew rate can be adjusted faster too.

I have a 130 SLT which uses the same mount and tracking. Backlash. If you dismantle the mount, fairly simple, you can tighten the two clutch bolts which takes some of the back lash out. Don't over-do it as we want them to slip if they have to. The drive plate for the EQ ( battery box holder out) is held in place by two rather small screws, these can become loose and let the left/right become very sloppy. The screws are really too small for the job but do not overtighten as they are into plastic. The sprockets are metal and like a good grease, not too much but congealed yuck is not a good lube.

I have since found prime focus mounting using a M4/3 is to find a short T to M4/3 "15mm" adaptor (they usually come with a sleeve to convert to "45mm" and screw it onto the 2-in adaptor on the telescope focuser. Then fit camera, The M4/3 cameras have a short back focus (no mirror box) so the normal 45mm deep camera adaptor will be too deep and the telescope focuser wants to try to get inside the telescope. Eyepiece projection mount is better, for one thing the sensor is not open to the elements, The eyepiece fits inside the adaptor which can be screwed to the 1¼ plate or to a Barlow. The camera fits to a sliding tube to adjust back focus, without which the eyepiece can get too close to the sensor and will never focus. I now have various cameras to play with E-PL7, G5, G7, GH4, E-M5ii. The G5 tech is too old. We do need a Bulb, Live-Bulb, Live-Time. The E-M5ii has 5-axis stabilisation and it works a treat. The GH4 heat sink is impressive and really does remove electronic noise, it is also biased to sweep stray electrons from the sensor; which is why the Olympus cam shoot video for about 4 minutes before things turn magenta, and the Panasonic indefinitely. Both have advanced functions. Noise reduction should be turned off or they will remove faint stars, both can do a form of stacking in-camera but we don't want that. Remove hot pixels by re-mapping the sensors before use. The sensors are only 16Mp but that is big enough to print over 4-ft- by 3-ft. For low light sensitivity, sensor size is completely irrelevant; as a retired radio-metrologist I can quote chapter and verse on that.; the important thing is the light gathering aperture, the F-number.

Having difficulty more than a little bending down making the red dot 'thing' nearly impossible to use for alignment setup, I have fitted a camera piggyback to 130 SLT scope. This is a Panasonic FZ200 bridge camera with a remarkable zoom 1x to 24x at constant f/2.8. Not used for photography as such but to get a star in its cross-hairs before aligning on the scope, instead of trying to use the red-dot. Camera mounted eyepiece-projection is a M4/3 either Olympus E-M5ii or Panasonic GH4; the former has 5-axis stabilisation, the latter a heat sink on the sensor for lower noise. Has anyone else may use of old kit to aid set up alignment?

I/we have the 130SLT which I think is almost the same tube, there may be differences in the focuser: the 130SLT has both 1.1/4 and 2-in focuser parts; this may mean this model has deeper travel focus range, there are differences between models/years. It also comes with the 1.1/4 T2 adaptor. I use micro four thirds cameras (aka CSC or DSLM). The ones I have with remote cable release are the G5 and the GH4. These are mirrorless which places the sensor some 15mm closer to the lens mount than a DSLR. The drawback is that with the lens off the sensor is open to the sky; I have had to clean the sensor after using it on the scope. With a DLSR there is a mirror/shutter concealing the sensor and protecting it from the elements. Consequently I like to use a Barlow to enclose the sensor access. A plain or clear UV filter would function just as well . I can achieve prime focus using the short nose and lens mount adaptor but not with the longer Celestron 1.1/4 T2 adaptor (as shown above). The lens mount adaptors can be obtained in various lengths to adjust the back focus e.g. ask Zoltan at 365astronomy. The normal long adaptor is for fitting "legacy" lenses onto the camera at the position they should be if the camera had a mirror box, approx 35mm from sensor. Some adaptors have a 2cm tube which can be taken out; a short M43/T2 adaptor. Different length lens mount adaptor should be available for DSLR but you have less wiggle room than does a mirrorless system camera.. Getting the camera to prime focus is something of a matter of guesswork. I have before now resorted to screwing the lens adaptor straight on to the focuser as it also has a T2 thread with its eyepiece collar unscrewed. The magnification should vary with the distances between secondary to Barlow lens and Barlow to sensor; these can be fiddled with. I can almost image the entire disc of the moon on the x2 Barlow alone. If I fit an eyepiece as well then I have to juggle extension tubes as the back focus has altered again; only the short 9mm will fit inside the adaptors without screwing tubes together Heath-Robinson fashion, and then finding I cannot get a focus point But like I said, I do not like having the delicate sensor exposed. A digital camera with its state of the art sensor is much more sophisticated than a CCTV or webcam and far more expensive.

29/01/2015 - 30/01/2015 New toy day - laser alignment tool. I thought the 130SLT was working pretty well until I checked the collimation: way out. There should be a warning that your new scope will be off focus until a laser alignment tool is used and the collimation corrected. So that done I got the scope outside only to have the batteries die. Then I found that my 12V PSU is the wrong polarity. So I got the NiMH fast-charged, and of course the skies clouded over 8/8 with some heavy stuff from the west for the rest of the foreseeable.

Possibly worth having a trawl through Flickr's Infrared Photography Group's forum because they regularly perform major open-sensor surgery on cameras. Pretty much the same tech as here. https://www.flickr.com/groups/infraredphotography/