Seoras

Well I’m almost positive that Knightly2112 is correct with their diagnosis. I removed the casing from the other side of the mount and had a look at the gears from that side; there’s definitely a lot of play in the tiny gear shaft and I think the bearings look a bit squint. I’ve sent an email to Celestron support to ask them to fix it for me as I’m not dexterous enough to work with such small components (shaky hands 🙌). Not sure how long it will take to get the mount back from them but I’ll report back here once I know more. Meanwhile thanks very much to everyone who contributed to this thread, I really appreciate your help,

take care, Seoras 👍
 

2 hours ago, Knighty2112 said:

Yes, looks like an issue with a bearing. Just took some photos of my 8SE goto mount and you can clearly see the bearing if you take the other covers off the other side. 

 

If you take the gears off and the collar with the grub screws, you should be able to see if the bearing has totally gone. With the amount of movement I suspect it has broken.

 

 

Thanks very much, that makes things a lot clearer. I’ll take the other cover off and see what’s going on 👀

9 minutes ago, DeanCJ said:

Hi Seoras 

looking at your first two videos there seems to be a lot of sideways play on the geared shaft. I would suspect that a bearing has perhaps failed, or there is possibly excessive wear to the shaft. If you have a small inspection mirror, such as what a Dentist uses, I would try and look behind the plate with the three cap head Allen screws, you may get a better idea of what is happening. Small bearings are widely available online. Perhaps it would be worth searching YouTube.

Thanks for your help. I did think the sideways movement was excessive but I’m new to telescopes so wasn’t sure if it was something that is built in as part of the backlash compensation. The gears seems quite small and flimsy considering the weight they’re moving so it wouldn’t be surprising if the bearings failed 😞. I’ll try to see what I can as per your suggestion with the mirror, it would be great if I could fix it myself rather than send it off to Celestron for a repair. Thanks again 👍

Hi, I’ve been having problems lately with my Nexstar 8SE. There seems to be an awful lot of play in the alt axis; I got in touch with Celestron support and they suggested it might be fixed with the backlash settings but I’ve had no luck so far. There is probably about 4-6mm of “loose” movement and the scope will slip downwards at the slightest touch. When trying to adjust the backlash settings I could hear the motor engage to compensate for backlash but it still leaves the looseness. I looked online and found a video that shows how to tighten the clutch with a big nut on the mount but mine is already tight.

I’be attached a couple of videos to help illustrate what I’m talking about but they don’t seem to give a good representation of the extent of the movement. Any ideas?

thanks, Geo 

Hi, I’ve taken a couple of photos of the moon with my Nikon D3100 attached to my Nexstar 8SE and although they are a bit out of focus I was pleased to have at least something to transfer onto my laptop. I bought a second hand Nikon 50mm lens since I only had the camera body so I could use it without the scope and I would now like to buy another lens for variety. Can you suggest what I should go for next?

many thanks 🙏 

I’ll have a tinker with it tomorrow bearing in mind all your comments, thanks for helping me out 👍

Hello everyone, I’m sorry if this is a stupid question but I’m not sure if I’m doing things right. I bought an Astro Essentials dew shield along with a Celestron Dew Ring for my Nexstar 8SE and I’m very happy with both. Thing is, my scope became nose heavy with both fitted so I slid it back on the dovetail bar to compensate and that was fine. Then I thought I’d have a go at taking a couple of photos with my second hand Nikon and the T ring I bought for it; yes, you guessed it, the scope was now tail heavy. Will I have to slide the OTA back and forward every time I fit and remove the camera or am I doing something wrong?

P.S. I know my kit isn’t exactly great for astrophotography but it’s all I can afford atm 😩

No fungus for me then, glad I asked 😊. I’ll start looking for a manual 50mm and see what’s out there, as always, really grateful for your advice 👍

I’ve been looking online for a cheap lens for my cheap Nikon D3100, don’t want to spend too much as the camera was only £69. Some of the adverts say there is ‘some fungus inside’ or ’light scratches on the lens’. Should I be avoiding these at all costs or is it possible that these issues won’t affect the images as the sellers are saying? Also, is there a particular lens for this camera that would be more suited to astrophotography? As I’m a complete beginner I’m not looking for perfection, just the chance to practice taking photos before I buy something better,

many thanks, Geo

9 minutes ago, MarsG76 said:

The 8SE is capable of some great images... the long focal length is a challenge but doable... I imaged with a 8SE and a astro modded Canon 40D for years... Adding a f6.3 focal reducer will get the whole moon into the frame with a APS-C sensor sized camera like the D3100.

Now I'm still imaging with a 8" SCT, same spec as the 8SE and with a QHY268M, same size sensor and still happy with some of the images I can get with that setup.
There was a total lunar eclipse visible from here on 8th November and the images I posted were taken with the C8, a f6.3 reducer and a unmodded stock Canon 40D... definitely doable.... the only change I did with my 8SE was to put it on a CGEM mount, but that more for long exposure DSO rather than moon photography.
Controlling that focal length comes with practise and is also more effected by seeing quality.

MG

I think I’ve read about a focal reducer, since my Supreme Commander is now asking “do you really need that?” I’ll have to tread lightly on the buying front 🥴. Maybe I can persuade her to think about it as a Xmas gift 🎁!

52 minutes ago, ONIKKINEN said:

I would not worry about the big pixels for DSO work, in fact they are helpful for almost all setups as big pixels gather more light than small ones so the whole process of imaging goes by faster (in terms of how long a subexposure needs to be and partially how long an exposure is long enough in total). 14MP is still a very high resolution image for astronomy work, and unless you have excellent seeing night after night and a mount that guides your large aperture scope flawlessly, you are going to be oversampled even with that.

For comparison i bin x2 to 7.52 micron pixel size or x3 to 11.28 micron pixel size with a 200mm scope guided reasonably well on an AZ-EQ6, so you definitely dont need to worry about 5 micron pixels being too big.

Thank you for this 👍, another useful piece of information 

regards, Geo 

51 minutes ago, Mandy D said:

It is my pleasure to help and glad you found my reply helpful.

I had a D3100 as my first DSLR and it was a great little camera, but it got replaced with a D3200 for better resolution (24MP) and then I added a D800 (36MP, full frame). What lens or telescope are you using for the Moon?

The crop sensor will be able to capture the full lunar disc with focal lengths up to about 1500 mm, but it is better sticking to less than about 1200 mm as the Moon moves pretty fast through the frame at these focal lengths. It should do a great job on the Moon. I have plans to image the Moon again this week if the clouds clear. Please do share your photos in here, it will be nice to see what you achieve with that camera.

I don’t have a lens for the camera yet, I’m currently surfing EBay for a cheap bargain 🥴. My telescope is a Celestron Nexstar 8SE, I’ve been advised that the focal length is too long to capture all of the moon but I’d be happy to get anything that looks like the moon. I’ve been watching “The Old Gazer” on YouTube because he has the same telescope as me and a Nikon camera, (he’s about the same age too😉), he seems to do ok and is aiming at total beginners like me. I also find this forum to be super helpful and everyone is so friendly and understanding. I got quite a few things wrong when I started buying equipment and no doubt will continue to do so but I’m sure it’s all part of the learning process. 
regards, Geo

22 minutes ago, Mandy D said:

The D3100 does support multiple frame continuous shooting mode, but only at a maximum of about 3 fps until the buffer is full, then it will slow down even more. You cannot set it take exposures for a set time period as far as I know and what you need is your "remote shutter thingy" to do this.

It has a resolution of 14 MP, which is quite low compared with later cameras, hence it's pixel size of 5 um is large, so to get high resolution on small objects, like the planets you will need extreme focal lengths. For deep sky, it's sensitivity is low, so will need long exposures. Overall it is not a bad camera. It will work great on the Moon.

What a fantastic answer! Thanks very much for bearing with an old guy trying out a new hobby. I’ll have a go at photos of the moon first, I think this week will be good for that,

take care, Geo

Hi everyone, another noob question! I bought an old Nikon D3100 camera (body only) a couple of months ago and have been spending some time trying to learn how to set it up for astrophotography. I know it’s not ideally suited for the job but it was cheap and I thought it would be ok to practice on since I have no other cameras; I’ve bought a T adapter and can now fit it to my scope. One thing I’m not sure about is if the camera can be set to take multiple exposures for a given period of time automatically, I have a remote shutter thingy which has a locking facility, is that how I can do it or is there a setting on the camera for this?

thanks in advance, Geo

Here’s hoping 🤞 

Fantastic photo of my favourite planet 😊

Welcome, I’ve found the people on this forum to be extremely helpful and supportive, I’m sure you will too,

take care, Geo

15 hours ago, Philip R said:

Hi Geo.

It is a TeleVue Ranger... 70mm/480 semi-achro mounted on a Tele-Optic Giro GR-DX ll.

Nice, you have a great set up 👍

I’m in Central Scotland and the weather has been poor here too. Thing is, the forecast is rarely accurate so planning ahead isn’t really possible, fingers crossed things get better soon 🤞

7 minutes ago, Philip R said:

Hi @Seoras ...same from me too!

No issues with the finderscope positioned on the underside on my C6/SCT.

Thanks Philip, what is the scope on the right?

1 hour ago, SmokeyJoe said:

Don't know if it would help but I put a rubber mat over the power cable running from my house to the mount, stops me tripping over them in the dark. 

Why didn’t I think of that Joe 🥴? Thanks for the advice 

I’m sorry for posting so many questions lately but I have a lot to learn and everyone on this forum has been super helpful ☺️. I bought a new finder scope and on my first real stargazing night I noticed I was having difficulty seeing through it because I’m a wheelchair user and the finder was mounted just a bit too high on my telescope for comfort. I have moved it to a lower position on the scope but wanted to ask if this will be ok before my next viewing session so that I can put it back to the top. I’ve attached a photo so you can see what I mean,

regards, Geo

6 minutes ago, Franklin said:

Your garden must be facing due south then and that's really good because objects reach their highest in the sky when crossing the meridian in the south, (Nothern hemisphere observers).

Yes, and I asked the council if they could do something with the street light that’s adjacent to my garden and they came and changed the light fitting so I have reasonably dark skies👍

12 minutes ago, josefk said:

As @Franklin points out - this is where your picture of the bright heart of M42 is @Seoras - the trapezium stars (the blurry tight group in your picture) and three bright stars  in a line below them in the sky but to the left in your star diagonal view (themselves all just below another Messier - Messier 43).

 

which in the bigger picture is here below Orion's belt:

 

Absolutely loads to see in this area :-). As Franklin says UHC and O-III filters all help bring something out with Orion but then so to does good dark adaptation and a clear sky - it's so bright filters are the "the cherry on top" but its lovely and rewarding without.

It's good that there's lots to see because my garden is well placed for viewing Orion and it's one of the few targets I can recognise easily. I'm off now to price some filters...

21 minutes ago, Franklin said:

Have you got or tried a UHC filter yet? They are amazing and really help with contrast, making the nebula "Pop".

I'll have a look at them thanks very much!