Clarkey

I only have 2 cables going to my scopes - one for data, one for power (12v). I have a USB3 active cable for data that connects to a 12v powered USB hub. The power cable goes to a home made 'power box' which is a bit like the Pegasus one. It has 4 12v outputs, 4 usb power outputs and 2 dew heater outputs and was made from a small electrical junction box. Probably costs about £60 all in.

The other scope has a powered hub with 4x data and 3x high output (charging) USB's which I use to power the dew heaters. Also a 4x 12v homemade power box. Both systems have been faultless (so far🤞)

Apologies for the onlooking child - he photo bombed....

3 hours ago, Lotinsh said:

I mean if nasa uses it what could go wrong

Mmmm. Not sure this should be considered a selling point🤣. I remember a big telescope they built with a wonkey mirror - now was it inches or mm's.............??

Good advice above. Just a little addition

I am really an imager more than an observer, but you could consider some filters to improve visibility. These could be used with both the SCT and refractor. Maybe something along the lines of a UHC filter or even an OIII filter might help with with the views. Again, the effectiveness will depend on the LP.

6 hours ago, StuartT said:

I could never do that. I'd be too worried about it starting to rain and then waking up to thousands of quids worth of destroyed gear!

I understand this - it is my worse fear too. I do use a rain app called 'rain alarm' which uses rain radar to alarm. It seems pretty good but I only leave the kit outside if there is no rain forecast as well.

5 hours ago, The Lazy Astronomer said:

The advantage of set point cooling on an astro cam means you can build a darks library to reuse many times, negating the need to take darks every session, provided you stick to the same camera settings.

This is the main advantage of set point cooling. You can create a darks library and to have to waste imaging time creating darks. Also, if you are like me an need some sleep, you can take your flats / flat darks prior to imaging and set everything going and go to bed!

5 hours ago, The Lazy Astronomer said:

pick a gain

There is a large drop in noise at a gain of 100 so this is probably a good starting point.

I think both are pretty good value. Personally I would go for the SW as it is going to be a slightly larger aperture for a similar FL (with reducer / flattener). I am also slightly bias in that I have an ED80 which is excellent for the money.

Could you not use the 12v supply and put it straight into a USB socket and then get a USB powered dummy battery?

Andoer Dual USB DR-E17 Battery Adapter compatible with Canon 77D 200D 750D 760D 800D Cameras: Amazon.co.uk: Electronics & Photo

Thlevel Dual USB Charger Socket, Dual 5V/4.2A USB Car Charger Power Outlet with switch for 12V/24V Car, Boats and Marine, Motorcycle, Truck, SUV, UTV (1x USB Socket Blue) : Amazon.co.uk: Electronics & Photo

4 hours ago, StuartT said:

Thanks. Any particular recommendations? I hear ZWO are very good (the best, even?)

I have a mono camera, but if I was in the market for a OSC with your budget I would definitely be looking at the ASI294. In my opinion it is probably the best overall value for money.

3 hours ago, Astro Noodles said:

They have tested the Skyguider Pro and agree that it is not functioning correctly so have sent out a replacement

Great news. Hopefully you can get the images your efforts deserve.

I would not expect anything else from FLO. In all my dealings with them they have been first rate.

Really great version of M13. Goes to show the integration time pays off even on globular clusters.

22 hours ago, Ibbo! said:

Astrodon Luminance Tru-Balance E-Series Gen II: 15x299" (1h 14' 45") bin 1x1
Astrodon Luminance Tru-Balance E-Series Gen II: 30x300" (2h 30') bin 1x1
astrodon LRGB set: 44x300" (3h 40') bin 1x1
astrodon RGB Gen2: 30x299" (2h 29' 30") bin 1x1

Can I just ask one question. Why the 299s exposures? Am I missing something obvious?

Maybe come the darker nights I'll give it another go. I appreciate that it probably is the best tool for the job once learnt- but unfortunately time is a very precious resource for me. (7 and 9 year old boys and full time job). However, now I have largely got to grips with the data gathering I guess this is the logical next step.

On 04/06/2021 at 08:53, wimvb said:

 I've made the comparison before, but the difference between PI and PS 

Perhaps a little harsh. However, it does also highlight the one major failing in PI - it is completely daunting to newcomers. I could work the second one - the first would just cause me to run away🤣

I suspect it is the best option overall. However, I use APP, Startools and Affinity because I actually understand what I am doing. At some point I will consider PI again, but when I watched one of the training videos I still did not really understand what they we doing!

Well I have tried the Reego (TSRCKOLLI) and it has certainly worked to a point. I used a camera on live view with a zoom lens to get the secondary collimated. I did have slightly more of a problem with the primary as the line round the baffles I am supposed to look for (according to TS optics video) did not really exist.

Collimating a Ritchey Chretien telescope with the TSRCKOLLI tool - Bing video

I visually got it as good as I could. With hindsight I should have highlighted the baffle edge- maybe using some white tape or something similar. If I am doing it again I will certainly try this. Anyway, despite the general level of cynicism (from me and others) the Reego does seem to work fairly well and good enough that a final star test should yield good results.

As yet I have not managed a proper star test, however I can see the headlights on the M6 three miles away which works quite well. The collimation on the primary was slightly out (8th of a turn) which I have adjusted out. I have not done a full field check but so far so good. Once I get a real star test done I can start looking at optimizing the FL......

5 hours ago, codingquark said:

Buy RC8, mount it on EQ5 GoTo mount and use it for visual. Save for NEQ6 + imaging train and start AP.

Yes this is realistic.

Personally, I would buy the NEQ6 and a something like a 150 or 200PDS then you have an good AP set up and a pretty decent visual set up too. The finder on the newt could be converted to a useable guidescope quite easily using a converter (look on the FLO site for guidescopes).  Then save and get your AP equipment and then if you are still enjoying it 'upgrade' to the RC8. Also you can get some practice in with the collimation of a newtonian. The benefit of this way is you will not be needing to sell or replace anything on the way. A 200PDS at F5 and 1000mm FL is a good set up. You will need a coma corrector - but they regularly come up for sale second hand.

Good luck whatever you choose. Keep asking the questions on SGL - the people on here are always eager to help. I would have been lost without the forums. In AP terms I am still a relative beginner (but very experienced at spending money on it), but there are some experts on here that I always worth listening too.

The RC8 is a great scope - I have one which is one of my two imaging scopes - this and an ED80. The main 'issue' with the RC8 is that the long FL. At 1600mm is is pretty long and by the time you get all the astro gear on it you need more than an HEQ5 - mine is mounted on a AZ-EQ6 which is much more sturdy than the HEQ5. Additionally you will need a guide scope or ideally off axis guiding which adds more complication and cost. In terms of FOV it is very narrow which is good for small stuff like galaxies but not good for nebulae. You can always crop a widefield image - you cannot make a narrow one bigger (without mosaics). The other consideration is pixel scale. Depending on what camera you are using and what you are planning to photograph this needs to be considered. Typically you would want to aim for about 1"/pixel. With my RC8 at native FL and the asi1600mm I get around half this so I bin the data 2x2. You can only really do this with mono. If you are using OSC or a DSLR you don't get this option and will be oversampling. In general terms due to the seeing in the UK there is actually little benefit in going over a FL of about 800mm with modern CMOS cameras due to the seeing. You can just crop the image to make it 'bigger' in the frame.

I am not sure on your budget, but the most important thing is the mount. You can have the greatest telescope in the world, but with a poor mount it will be worthless. If you are serious about long FL astrophotography spend the money on a good heavy duty mount such as an NEQ6. This will then cover you for most 'standard' sized scopes. If you want to put an RC8 on it then great - but equally it will handle anything much smaller.

Have you considered a newtonian for imaging and AP? Something like a 200PDS is a good AP scope and is also good for visual. Even something like a 130PDS which will go on a lighter mount can give great images at 'sensible' cost. There is a great thread on this forum which shows what is possible.

At the end of the day it is down to budget and patience. There is nothing to stop you starting with a long FL RC8, but it is harder than starting with a widefield scope.

1 hour ago, ollypenrice said:

A Star Adventurer mount with camera and lens would be a good way to start

Within your budget this is good advice. See how you get on with a few lenses and take it from there.

6 hours ago, nephilim said:

In a nutshell the answer is no.  Astrophotography is a  horrendously expensive  money pit that keeps on taking.

If you go beyond a simple star tracker this is too true. However, if you are willing to buy second hand and are patient and careful with your purchases you can keep the costs down - but it will still be costly.

Looking at the graph the system certainly seems to be oscillating in RA. As rnobleeddy has pointed out running the guiding assistant is certainly a good option. Reduce the aggressiveness of the guiding response would probably help.

Also, make sure the FL of the guidescope is correct in the settings.

Hi Codingquark and welcome to SGL.

Quite a bit to cover so I will try to keep it short.

Firstly, visual and astrophotography are very different beasts with very different requirements. Generally for visual, aperture is your friend and for easy of use some form of alt-az mount is desirable. In this case the 8-10" dobs or newtonians are very good. You might want to consider a goto tracking mount, but again to avoid general contortion trying to get to the eyepiece alt-az is still the 'better' option.

For AP you are looking at a equatorial mount which needs to have good tracking to get longer exposures. Aperture is less important. AP is also a very expensive rabbit hole to go down. Ask anyone here! It is possible to do AP without an GEM, but you are making life difficult to start with.

I would strongly suggest getting a copy of Making Every Photon Count before looking at AP. It is a good guide to the type of set up you are likely to need.

Making Every Photon Count - Steve Richards | First Light Optics

In terms of your choices above the Redcat is a popular choice and a good starter for AP in terms of cost and ease of use. For the ES scope you will need at least an HEQ5 or similar to give good tracking accuracy. The RC8 is just too heavy and would really need a NEQ6 or similar by the time all the AP kit has been added. Also, the the refractors and RC would really need guiding due to the FL. RC's are really designed for AP and are not so good for visual. Also, at the long focal length they are not easy 'starter' scopes.

In general terms, I would suggest if you want to do visual and AP, the refractor and EQ mount would be the way to go. Personally I would keep the AP and visual separate otherwise you end up compromising on both.

Hope this helps.

On 22/06/2021 at 10:37, GiorgioF said:

Tonight I will check the orthogonality of the focuser as last chance and let you know.

I was just wondering how you got on? Any progress?

18 minutes ago, vlaiv said:

M31 is actually moving at a speed of 110km/s towards us

Oh oh. Don't tell the tabloids🤣

Sorry..... Should be taking spacetime seriously.

There is certainly some good data there and with a bit of tweaking you should be able to get the result you want.

Looking at the second image there is certainly more detail but also more noise (as you would expect). I found with Startools that for many subjects the Autodev function had a tendency to slightly over-stretch the data and even after de-noise there would still be a lot of noise. Two options really. Firstly when running the de-noise module push the grain size up quite a bit. It will soften the image but give a better overall result. The other option (which I often use with ST) is to run a manual develop and not push the data quite so far. I have found the final results slightly more pleasing.

Also, if you are using Affinity you could use the Astroflat pro plug-in, or just run a denoise routine . Both of these might help your final image.

Hope this helps.

I have just been communicating on another post on exactly this issue. I have a Reego (TS) collimator and I am going to try it for real tonight. Fingers crossed.....

I'll update when completed and star tested.

Advice from Ritchey-Chrétien owners please - Discussions - Scopes / Whole setups - Stargazers Lounge

Just a couple of thoughts from me. Firstly, is the focuser straight? If it is off line this will affect the secondary position. Also, looking at the design, would it be possible to rotate the spider vanes by 180 degrees as this looks like this might move the mirror out slightly?

Thanks for the input gents. I am 'home alone' this weekend so I will have a go with the collimation without any distractions.

8 hours ago, davies07 said:

It'll be a step up from your 200P and in a more compact package.

I have not actually imaged with the 200p (although I do have the kit to do it), only the ED80 and the RC8. I have managed some pretty good images, but knowing the collimation is slightly out, I know they should / could be better. The slight error is also magnified when using the reducer. I think the inter-mirror distance is pretty close as it plate solves only a few mm out. (I know the inaccuracies of the mirror may make the required distance slightly different in reality - but it is a good enough starting point).

This is an image I got earlier in the year - before short nights took over. Do you think I expecting too much and should just leave it alone?

20 minutes ago, Dmelv said:

Does one focus fit all objects?   Does one back focus fit all objects?

Yes and Yes... But you would probably need / want to refocus or check the focus after a while as it will drift with temperature / filters etc. But if you are focused at infinity (stars) that focus is fixed.

22 minutes ago, Dmelv said:

I am using a refractor with a field flattener - so the draw tube focus does not affect the camera image sensor in the same way with focusing movement as it would without the flattener   is this a true statement?

No - the drawtube focus will still affect the 'normal' focus. The difference will be that the stars right across the field should be in focus and sharp. Without the flattener you would only be able to get part of the image in focus. If you have a very small sensor you might get away with it, but any larger sensor would show distortions.

The total 55mm distance is from the shoulder of the reducer / flattener to the sensor. So as you say in your case the 37.5mm from the front of the camera to the shoulder of the reducer should be correct. This figure is approximate and you might find to get a 'perfect' result that you might need to deviate from this value slightly. For example in my set up I have had to add about 0.5mm extra to get a completely flat field.

You can focus during the day, but you will be better off focusing using the Bahtinov mask at night. Focusing at infinity in daylight leads to a lot of atmospheric distortion which makes accurate focus difficult - but you can get close.