malc-c

But was the centre of gravity checked as shown in that video... The thing is that looking at that image, after the initial jumping around the mount was being guided at the end. - Seeing that the zig-zag traces at the start are first in DEC and then in RA it would suggest that is some part of the calibration run, or similar before PHD finally gets round to guiding.... - It may well be that you are looking at the graphs whilst it does the configuring and thinking there is an issue, when in fact there is nothing really going on? - I must admit however that I don't see that behaviour with my guiding, so maybe there is still more to this than we know. Can you describe exactly how you have the computer connected to the mount, if the ST4 cable is removed etc... just for clarification.

Sorry, I was confusing the current draw of the steppers as measured in an goto system. D cells are 1.5v, so will provide 6v. The 4.8v would be the voltage or 4 x rechargeable (NiCad / NiMH) as each cell maxes out at 1.2v - If running them at 1.2v below the suggested voltage has no effect on the tracking then that's fine

IMO the USB port will not be able to provide the current required to drive the mount, and will be a volt less that that needed. Ideally you need a 6v 3Amp power supply with a 2.1mm tip positive plug to power the mount. You might get away with using the powerpack - trial and error, but if the slewing stalls or tracking is slow then you may have to stick with using D cells or adapt a 6V motorcycle battery

Oh I totally agree... An EQ3, with simple RA Drive, and a telephoto lens and camera is an ideal start into wild field imaging... and wouldn't brake the bank. But again is a different "category" of imaging, and may be something the OP might want to add to their list of things to check out. But getting back to the OP's original post, I took this to mean either using his 130 (ignoring the spherical mirror issue), or upgrading the complete rig. And by decent planetary images, took that to mean close up images rather than wide field. I guess it might help if the OP gave us a budget and defined what it is that they are hoping to achieve in terms of end results.

This was my first attempt at M51 taken using the equipment below... can't remember the number of subs / darkes etc....

In this day and age, this is going to be difficult. To get a mount that has the precision to track well, takes a decent payload and is solid it will be goto. By that I mean it will be driven and have the ability to be controlled by a handset or computer. You don't have to use the handset / PC to slew (goto) targets, but it is required to enable tracking. Something has to send the command to the mount to start tracking and to track in sideral rate. 30 years ago you could get mounts that had motor drives that constantly drove the RA axis at sidereal rate as soon as the power was applied so you positioned the scope at the target manually and then locked the clutches and away it would go... but with the advent of cheaper components and advancement in technology that evolved into the modern goto computerised systems we see today and is now commonplace on higher end mounts ( you can't get a new HEQ5 without goto for example). However for mounts like the EQ5 there are still options to drive the scope without having the computerised goto system. such as this dual axis kit , but whilst the EQ5 is a nice mount, it may not tick the boxes for payload and stability (as previously described ). I guess we have all been there... wanting to dip a toe into the water but not wanting to waste lots of money, but equally not wanting to buy something that doesn't perform.

In that image of the camera screen it seems that all stars are elongated, but the fainter stars haven't left traces as the scope moved, which would suggest that the movement between the start of the exposure and the end may not have been linier. It's like the exposure started, tracking started, and then tracking advanced slightly at a faster rate on one axis and then resumed at the end of the exposure. The fact the fainter stars didn't register the short distance gives the impression the exposure is of double stars. I've seen similar when the backlash in the mount hasn't been taken up after a slew. Can you confirm your scope is fully balanced? In this old but useful video explains the issue of balance and CogG I'll also try and remote into the observatory PC and take some screenshots of my set up which may help

Just googled the firmware and it's version 7.17.00310 which was released a year ago in April-2020 and it was to fix a bug with a particular camera. The previous version was in July 2019. - Synta (Celestron) provide their own CFM uploader for updating firmware available here for updating firmware on mounts and handsets, so presume this is what you have tried to install the update ? To be honest, there is a risk when performing updates and unless there is a particular problem then often it's best to leave things as they are. But seeing you have an issue it may be worth doing on the advice of the retailer. However googling the issue you will see you are not alone - here's one example - so maybe worth doing some more research before attempting the update

In the 400D (and possibly the 450D) there are two IR filters If you remove both and leave the sensor open then you will have a "full spectrum" camera. The drawback is that the sensor has no protection against dust etc, which is why some will fit clear glass as a form of protection. It also means that all wavelengths are passes, including those from street lights and other sources you don't want Most guides such as this one - give you some idea of what's involved in fitting the Badder filter

It would probably require a different cable, but if you had a PC-DIRECT cable connected between the computer to the handset, with the handset in PC-Direct mode, and then the handset connected to the mount, then all you would need to do is come out of PC-Direct mode on the handset and use the handset and normal to park the scope. The PC direct cables used to be a DB9 to RJ45, so you may need a standard USB to serial convertor to replace the EQ-DIR cable

So you are thinking of using something like an RJ45 "Y"cable ????? Uhmmmm Not 100% sure it would work - you would probably end up with having serial "packet" data corrupted as both devices would see the mount and be trying to communicate at the same time. You are basically trying to parallel TX and RX serial data to two devices at the same time - don't think it would work. Why don't you use whatever driver for the scope to perform a meridian flip - I know EQMOD can be configured to force a flip at a given point, but given the hardware would assume you are not using EQMOD as the driver

I opted to fit a Badder BCF filter - as detailed here If you are careful, take your time and have a steady hand the process is quite straightforward. This is how it effects the images - The raw unprocessed image on the left, and then simple "auto levels" in Photshop to correct. Naturally for DSO's you leave the red in And then processed slightly to remove the grain and make it more appealing to my eyes

Rob, from experience getting into imaging isn't cheap. To get a mount that is stable, tracks well and is solid then you're looking at best part of a grand for an HEQ5 as the entry level. Granted there are posts where people have used EQ3 and EQ5 goto mounts, and have got some exceptional results, but the hoops they jump through to get there can make the process frustrating. Best analogy is comparing a basic 1000cc car and a 3ltr audi. Both can do 70 on the motorway, but in the Audi its' less work and the result is smooth and refined. Whilst you are not looking for goto - it really makes thing easy and if you opt for DSO's that need guiding then the precision of the HEQ5 comes into its own. Imaging on an undriven mount would be impractical. But it also depends on what imaging you want to do. You have lumped DSO's in with luna and planetary. No one scope (and certainly not the 130) will fit all. The 130 would be fine for luna imaging, either with a single shot DSLR, or CCD camera. Planetary work needs a lot of magnification and aperture. Using barlow lenses to increase focal lengths will dull the image of Mars, Jupiter and Saturn, so you might get dissatisfied with the results. You could get some decent results with a DSLR for DSO's but due to the long exposures you will need to use guiding, so this then puts you in the realms of computer control, running PHD2, EQMOD and using an EQDIR to connect the mount.... so you could find yourself the deep end, and needing deep pockets, which is why having a decent mount that works well such as the HEQ5 is worth the investment. I'm speaking from experience. I started with a 200P on an EQ5 goto. I then wanted to venture into imaging as light pollution at the time was making visual observing difficult. I connected a webcam (Philips SPC900) and used a cheap netbook to capture the Moon and then processed the result in a free stacking application. I was happy with the result, but when I tried the same on Jupiter the results was underwhelming - I stacked two barlows to increase the focal ratio to f20 and whilst the disk of Jupiter was now larger, it was very dull. It also meant the detail was poor as the camera lacked the pixel count to give a decent image. I then switched to using a canon 400D to try DSO's and soon found that I couldn't get longer than 60s exposures before tracking errors spoilt the image. It was at this time that I invested big time and upgraded to an HEQ5, with a ST80 and QLY5 guidecamera, and built a RPR observatory to house it in. Now I can be up and taking my first image in less than 15 minutes. In hindsight I wish I had opted for the HEQ5 /200P option at the start, as I ended up selling the EQ5 mount and tripod for a loss.

But surely it can be that hard for a manufacturer to mount the lased LED central and parallel to the edges of housing.... I would have thought adding the option of some form of adjustable support would be more complex than permanently fixing the diode in place. Given the simplicity of the Hotech you would have thought the pricing would have been the other way around, but then all the cheap collimators don't have the self centering mechanism, and that is where the cost may lie. Plus as others have pointed out , the quality of the laser is far better than cheaper devices, making collimation more precise. For me it's nice to have that confidence in knowing that any error shown when collimating the scope is going to be due to the misalignment of the optics and not down to misalignment or calibration of the tool I'm using. If it means paying that little bit extra then I have no issue as I know it will save me time doing the task in hand. But let's face it, astronomy is not a cheap hobby...

I can't see how you can get two stars of every star in one image (like a double exposure) as you would get trailing between the two stars suggesting the mount isn't tracking. Try this.... Power up the mount and the PC Launch your planetarium software and connect to the mount via EQMOD (don't use the toolbox - that is for setting up and testing) Select a target and slew the scope to target Check that EQMOD says tracking - if not then enable sidereal tracking Open PHD2 - Select the option to connect to the mount and camera (connect all) Click the cycling button so a star field is displayed. Click on the brain icon - there is an option to force calibration under the guiding tab - this clears any existing calibration settings - save and exit Choos a star - or use the option to have PHD2 chose its own star. Click the guide option and PHD2 should do a calibration run. Hopefully it will run through without complaining When complete the cross wires should go green and the mount should start guiding. Watch the graph, after a few minutes it should settle down and whilst the traces may not be flat they should stay within a range and follow the zero line rather then trend up or down by a large amount. Then open your imaging application - it should detect what's running and connect to your imaging camera. Take a test exposure, which for me using a DSLR is typically 120s which will show up any issue and confirm the framing. Posting up information on your planetarium software, and the images you are getting will help further diagnosis.

As others have said, they are factory collimated and they never seem to drift.... I've never seen the point in buying a collimation tool that itself needs to be collimated. If you don't set the tool up right then it won't set the scope up correctly. Can you imagine buying a bubble spirit level and being required to adjust the position of the bubble

Basically this was what I was trying to cover. From DSS website Star detection For each picture DeepSkyStacker will attempt to automatically detect the stars. In simple terms, DeepSkyStacker considers that a star is a round object whose luminance decreases regularly is every direction, and whose radius is no more than 50 pixels. Note that DeepSkyStacker will reject elongated star images which might occur if your mount isn't tracking correctly. I've underlingned the point I feel might be an issue. If the exposures are long, without tracking there could be enough elongation of the stars for DSS to reject the image and discard the image. In the past I have managed to stack images where the camera had been removed and replaced resulting in some subs being 90 degrees to others (IE like stacking portrait and landscape images of the same subject) - It worked, but that was because all images were taken with a guided EQ mount and the star shapes were nice round and the triangulation algorithms DSS uses still worked. I had to set an area in DSS that was inside the overlap for it to work, but it still means that that I didn't have to throw away a previous sessions data.

Like I mentioned I'm no expert, and a lot of what Vlaiv mentioned went over my head, but from what I do know is that I think you are faced with a couple of fundamental issues. There is a relationship between focal length and exposures. It's probably no linear but at a guess for a given ISO and same aperture you need to expose twice as long for a scope of twice the focal ratio. But the problem with long exposures is that you need to guide (unless you have such a high end mount that has fantastic tracking and minimal PEC. Now an ALT AZ mount has two issues where imaging is concerned which compound the problem. The first is that guiding becomes difficult as the drift tends to be on two axis rather than one when comparing an ALT/AZ mount to an EQ, which is related to the second issue of field rotation. If left unguided a long exposure will result in field rotation, which is approx 45 degrees in a three hour period. This can then lead to stacking issues because each sub is rotated a few degrees. So I guess to improve things you either need to consider a focal reducer or fit some form or wedge so the scope can be used in an EQ format and then possibly consider guiding so that more data can be gathered.

Hi Stuart, I'm no expert, but 46 x 30sec is only 23 minutes worth of data which isn't a lot IMO. Granted you have a high ISO, which can result in a more grainy image, but even when I was imaging at 800 ISO I would still gather at least an hour on bright galaxies such as M31 and M81. M51 is quite a faint target by comparison. Also that's with a 200P so like your SCT an 8" but at half the focal length as the 200P is f5. Do you have the LX on a wedge or is it in an ALT/AZ format, and are you guiding ?

LOL - You can include me in that camp.... I find it very frustrating when you gather hours worth of data, stack them and then get disappointing results especially when you know there is more details in the result, even after hours of fiddling with stretching and colour matching etc. My friend who is (IMO) at the top of the game when it comes to imaging (his main camera cost more than my 8yr old Volvo V70 !!) and has had many an image featured in Astronomy Now to my subs and performed some magic on it and got the result above ! - Would love to know what his secret is

Chris, Possibly the reason Synta (or Chinese manufacturing in general) manage this is due to cheap materials and up until recently, cheap labor. For years the quality of chinese motorcycles has been questioned, with screws so soft they need replacing as the first time they are undone the heads are chewed up. Not saying that Synta products are of the same standard, but I bet the steel and ali used is not as high a quality of something that used to be produced in Sheffield. On a slightly different tangent, I like designing and building electronics projects. The first time I needed a PCB made I contacted a local company that is a large producer in the UK. The quote that came back for the tooling, let alone the single board was over £500. I then discovered companies like PCBWay and JLBPCB in China, and had five boards made to the same standard for less than £50 delivered via DHL. Not sure what part of that £500 were for materials and the rest for "time" of the various technicians or managers, but it certainly makes UK companies uncompetitive. If Synta can make finished mirrors for less than you can buy a glass blank here, even at "trade" prices, then how could any UK company compete, especially as whilst Synta scopes are not perfect, they do perform well at their intended market level. But even when you look at the high end, made to order "connosure" market, companies like SuperScopes that were based in Bedford didn't last long. The costs of buying or making parts, either in their own workshop or subcontracted made these scopes so expensive there was no market for them, and their reputation was such that they couldn't buy cheap optics from China as they only used the best David Hinds optics. I think you are correct. Synta have cornered the market, especially if you work things back. I know retailers portray a poor sob story about margins being so small, but I would hedge a bet that the net material cost to Synta for say a 200P is around 30% the retail cost in the UK. The rest is Synta's profit margin, distribution costs, sole agent wholesalers profit, and then the retailers markup, with various taxes and duties added in.

There's a listing in the classifieds Here

Olly, I was going to add that to the equation, but thought it may complicate things. Most of us use EQMOD to handle the mount control, with guiding handled by PHD2. However the OP has a celestron mount which is not supported by EQMOD, and even if it did, wouldn't function as the clue is in the name, EQmod... for EQ telescopes. Personally, given that guiding is an aid to taking long exposures, the field rotation (15 degrees an hour) will be in issue, especially when trying to stack three or more hours worth as the software will most likely complain

OK I'm going to state the obvious here... you are using an ALT/AZ mount which will suffer the same issue of all ALT/AZ mounts and that is field rotation. Now if you guide on a star for long periods, I would have thought that may also be a problem due to the field rotation?? As for guidescope, I've used ST80 and now the stock Skywatcher 9 x 50 finder and found that both worked well. Given the weight saving the 9x 50 would be the cheapest option. You will need an adapter to suit the camera so you can connect the two (best speak with RVO or FLO). The 9 x 50 SW finder is £54, and should slot right in the shoe where the current 6 x 30 finder is. However, I would seriously suggest you consider looking at upgrading the mount to an EQ (ideally an Skywatcher so you can use EQMOD with an EQDIR cable) to really get the benefit of guiging for longer exposures. An EQ mount will also help with stacking and post processing the results as you won't have to deal with the field rotation issue.

Just received this PM from the "customer" It really pleases me when I read through this thread to know that I've been able to help five SGL members get their scopes back up and running. But I'm gobsmacked to see this all started almost a year ago ! - where does the time go !!