Daniel_J

6 hours ago, Giles_B said:

Yes, I wondered about the conditions. I was looking at the moon yesterday and the seeing was moderately poor from central Bristol - I guessed warm air preventing the airborne pollution from clearing. Always worth looking at an object on successive days.

For sure, here in Liverpool it's been really cloudy for a week or so causing me to be impatient and looking at the moon during the day. I think its the asphalt radiating heat during the day causing turbulence making the moon appear relatively blurry. 

1 hour ago, Spile said:

The alignment looks fine to me but I would recommend a Cheshire eyepiece and sight tube combination tool to confirm as per https://astro.catshill.com/collimation-guide/

Thank you, that guide looks amazing so I’ll definitely try it tomorrow when i get the chance. The moon definitely looked a lot sharper today when I was viewing it. Possibly due to better viewing conditions. 

3 minutes ago, malc-c said:

To be honest it's wise to invest in the tools for the task.  A cheshire or Hotech  collimator and a self centring adapter makes the task of collimation a lot easier. 

Rather than using the moon, do a star  test.   Find a bright star, then rack the focus to both extremes and look for the pattern of detraction rings that form.  If they are concentric like the image below then the scope is collimated

Thank you! I’ve been meaning to do a star test but it’s been cloudy for a week now and I’m very impatient so I’ve just been viewing the moon in the day when it’s mostly clear. I did do a star test a while ago and it looked similar to that picture so I think it was just my viewing conditions. I think through the collimation cap the mirrors seem aligned but I do need to do a star test asap.

1 hour ago, Ricochet said:

It's quite difficult to tell what's going on there. I think maybe the secondary is slightly rotated away. The secondary shadow gives it away the most. Do you have a cheshire/sight tube or concenter? You really do need one of those tools to collimate the secondary, a collimation cap is really only of use for the primary after the secondary is collimated.

With regards to getting a sharp focus, there are also other factors that can have a far greater effect than collimation so don't get too hung up over it.

• What eyepiece(s) are you having trouble focusing with? Is it the standard 10mm MA supplied with Skywatcher scopes? If so I would suspect that to be at least part of the issue.
• Are you giving your scope long enough to cool down before trying high power observing? You will probably have tube currents in the scope for at least half an hour after you get it out which will impact the views.
• What are you putting the scope on? Concrete and the like hold on to heat for longer than the garden lawn and with the scope being so close to the ground, ground thermals are going to be more of an issue.
• What are you observing over? If you're pointing your scope over buildings then again thermals coming off the buildings are going to cause problems. Trying to observe when the Moon is over fields or gardens will improve things. If you are observing over buildings, moving your scope back as far as possible so that the Moon appears as high over the rooftops as possible will be useful.

Yup. Of the ep’s are stock from the skywatcher 200p. The 25mm view is just slightly blurry but the 10mm view is pretty blurry. I see wayyy more detail in the 25mm than the 10mm because the 10mm just looks too blurry when I’m viewing.

1 hour ago, Ricochet said:

It's quite difficult to tell what's going on there. I think maybe the secondary is slightly rotated away. The secondary shadow gives it away the most. Do you have a cheshire/sight tube or concenter? You really do need one of those tools to collimate the secondary, a collimation cap is really only of use for the primary after the secondary is collimated.

With regards to getting a sharp focus, there are also other factors that can have a far greater effect than collimation so don't get too hung up over it.

• What eyepiece(s) are you having trouble focusing with? Is it the standard 10mm MA supplied with Skywatcher scopes? If so I would suspect that to be at least part of the issue.
• Are you giving your scope long enough to cool down before trying high power observing? You will probably have tube currents in the scope for at least half an hour after you get it out which will impact the views.
• What are you putting the scope on? Concrete and the like hold on to heat for longer than the garden lawn and with the scope being so close to the ground, ground thermals are going to be more of an issue.
• What are you observing over? If you're pointing your scope over buildings then again thermals coming off the buildings are going to cause problems. Trying to observe when the Moon is over fields or gardens will improve things. If you are observing over buildings, moving your scope back as far as possible so that the Moon appears as high over the rooftops as possible will be useful.

Hi, thanks for your reply. I don’t have a Cheshire, only a collimating cap. Everything appears circular and concentric through the eye piece but it’s hard to look through a pinhole so I don’t see very much. I am using a 25mm eye piece. I gave my telescope an hour to reach equilibrium to the temperature outside. My telescope was on concrete looking straight above. (The moon is quite high in orbit currently). I did see less more detail the more I looked. I got a couple pictures of the moon through the telescope through my phone by just holding it up to the ep which I think don’t really do it justice and I also drew on some circles to my previous image. 

Hi, I’ve been observing the moon in the day and no matter what I do it feels like I just can’t find that perfect focus. I’ve researched and people say it’s mainly down to collimation. Here is the view I see through my collimation cap, my focuser is backed all the way out: 

7 hours ago, OK Apricot said:

Rest assured, my 200P mirror looks terrible if I shine a light down there. The only thing I've cleaned is my Skymax 127 meniscus, but that was particularly bad. The saying goes "look through your optics, not at your optics".

The sombrero may be visible B5/6 with an 8" dob, I know it is from Bortle 4. Start by finding the constellation Corvus. It sits underneath the bowl of Virgo. You should be able to make out Algorab at the top of Corvus. What I then do is find the star HD110317J, a couple degrees north of Algorab. Under B4 skies this is faintly visible naked eye so I point my finder at it, under B5/6 I'm not sure if it's visible naked eye, but a little scanning and patience with the finder should do the trick. From there I nudge a little in the direction of Porrima and I'm looking for a formation of 3 stars close together - these are a useful pointer for the Sombrero! I should mention I start with a lower powered eyepiece for the widest field of view. A dob oriented view should show the 3 stars to the left of your image, and the fuzzy sombrero should be visible towards centre. Patience and practice is all it takes, but trust me it is worth it - seeing that bulging core and dust lane with your own eyes is incredible! With my 200P, I find a 20mm EP at 60x gives the best view. 

Star hopping is a bit of a skill, but I only bought my 200P 3 months back and soon got the hang of it. Use Stellarium or similar to find the bright stars or objects of significance near, or on your way to, your target. 

This is where I was when looking through my telescope, I will definitely try again when the sky clears up now that I have a better understanding. Thank you!

7 hours ago, OK Apricot said:

Rest assured, my 200P mirror looks terrible if I shine a light down there. The only thing I've cleaned is my Skymax 127 meniscus, but that was particularly bad. The saying goes "look through your optics, not at your optics".

The sombrero may be visible B5/6 with an 8" dob, I know it is from Bortle 4. Start by finding the constellation Corvus. It sits underneath the bowl of Virgo. You should be able to make out Algorab at the top of Corvus. What I then do is find the star HD110317J, a couple degrees north of Algorab. Under B4 skies this is faintly visible naked eye so I point my finder at it, under B5/6 I'm not sure if it's visible naked eye, but a little scanning and patience with the finder should do the trick. From there I nudge a little in the direction of Porrima and I'm looking for a formation of 3 stars close together - these are a useful pointer for the Sombrero! I should mention I start with a lower powered eyepiece for the widest field of view. A dob oriented view should show the 3 stars to the left of your image, and the fuzzy sombrero should be visible towards centre. Patience and practice is all it takes, but trust me it is worth it - seeing that bulging core and dust lane with your own eyes is incredible! With my 200P, I find a 20mm EP at 60x gives the best view. 

Star hopping is a bit of a skill, but I only bought my 200P 3 months back and soon got the hang of it. Use Stellarium or similar to find the bright stars or objects of significance near, or on your way to, your target. 

Thank you so much! They are some very helpful diagrams. Looking at them, I was very very close to finding it. I think what threw me off was the fact that the image through my finder scope is inverted so I was moving the scope the wrong way. I’ll have another go when the skies clear up here. I can’t wait to find it! Sombero galaxy is definitely up there with one of my favourites, a long with the whirlpool galaxy that is very good for viewing right now here in the UK.

Thank you all for the replies! Very helpful, pretty sure it’s just one of those seeds that likes to fly around. Was just a little concerned because I know pollen can really damage a mirror if left there for a long period of time. Completely of topic here: how do I locate sombrero galaxy and will I be able to see it with an 8inch Dob in bortle 5/6 skies? I got very close to locating it yesterday but just couldn’t pinpoint it disappointingly. Any tips from observers that have managed to locate it before?

Will keep it in mind, just love my things to be in tiptop shape. Convinced it’s not a scratch because of its weird pattern. Almost looks like a toddler drew a very wobbly “x” on the mirror. Pretty sure it’s just a seed. 

Thank you very much! I decided to repost because the other one had bad grammar and lacked detail. Thank you so much though! 

Hi, I have an 8inch sky watcher telescope I bought a few days ago. I love it! I’m very happy I picked it. 
however when observing yesterday night I did a flash light test on the mirror stupidly revealing all of the mirrors dirt. Well unsurprisingly I saw a little. I love to keep my stuff pristine, phone, Mac everything. 
when looking down the tube I noticed a scratch like thing that reflected different colours of light. Initially I thought it was a scratch but looking at it closely it looks like a dandelion seed. The white little seed that you see flying around occasionally. It’s stuck to the mirror as I tried rotating it round and it wouldn’t move. I’m just wondering if it’ll cause any harm. You can clearly see it below the primary mirror centre circle. Any answers would be most appreciated. Thank you.

Bought my newtonian reflector a few days ago. First scope. Below the primary mirror seems to be a hair/ scratch just below the primary mirror. I am anxious it is a scratch and want to know if it'll effect viewing. Its visible in varieties of light.