miguel87

4 minutes ago, DaveL59 said:

I meant for visual use if you move the mirror, you'd need an extension to bring the eyepiece back away from the secondary to hit focus  Moving the mirror up the tube brings the focal point up the focuser tube to compensate for lack of in-focus travel, but doing this for a camera has the potential drawback of rendering the scope not usable for visual, hence an extension for the eyepieces.

Moving the mirror by say 25mm isn't going to lose you much aperture so I'd not worry about that too much, 6 bolts and 3 springs for around £10 vs how much for a low-profile focuser...? Your call tho  

My call is neither! Honestly I wouldnt dream of changing mirror screws or anything like that. If it came to that I just wouldnt bother with AP. All I want to know is what is the best I can do with what I have already and it might be fun to take some photos. For me, visual is king.

I just thought, hold on, I have a telescope, I have a half decent driven mount, a DSLR and a T-ring adapter, why havent I at least tried to take some photographs other than the moon

I'm feeling positive that the dimensions of my DSLR are pretty normal and I should be able to reach prime focus. If I cant, I will just stop there!

4 minutes ago, DaveL59 said:

if you do find you need to adjust the scope, rather than cutting the OTA you might achieve the same effect cheaply by replacing the collimation and lock screws with longer ones and also springs to suit the extra length. That'd move the mirror cell up the tube to shift the focal plane and also be easy to return to factory later if you wanted to sell it on. I did this on my TAL-1 when adapting it to use standard 1.25-in eyepieces, am sure it'd work on your SW200 also.

You may find that you'll need an extension tube to use it for visual once done though depending on the amount of back-travel there is in the focuser.

No the 200p needs the opposite of an extension tube, that's why some people cut them or get low-profile focusses.

I like the idea with the mirror but I hope it doesnt come to that. It would also mean the secondary wouldnt see all of the primary so some aperture would be lost.

Thanks.

12 minutes ago, Viktiste said:

I did not have to cut my 200P to achieve focus with a Canon550D. Mounted like this:

Brill thanks. I have the black 200p too. The only difference in our setup would be the two speed focusser (depth looks pretty similar) and my camera is an entry level pentax but I dont know how much difference that would make.

Out of interest and planning my test run, what sort of FOV do you get with that set up?

6 minutes ago, 8324689 said:

I chopped my 200p to focus! 

 

I took off 5 cm - in retrospect I would have taken off 2.5 cm

That's what I thought and have read previously.

I am now lead to believe I dont need to chop or use a barlow and I can just use prime focus at the empty focusser?

Have you tried this?

I think it is mostly people's expectations are too high because of internet images and media, hubble etc.

Most people are suprised to learn that even in my modest 8inch newt and average/good skies, all the galaxies that I hunt are colourless grey faint tiny smudges.

Good luck and I hope you keep stargazing.

3 minutes ago, CraigT82 said:

You can work out your focal length...  all you need to know is the angular size of the object in the image (moon), how many pixels across it occupies in the image (use photoshop or gimp) and what you pixel size is. 

Angular size in the image is not possible to calculate? Depends how close I hold the picture to my face.

Oh sorry you mean the actual moon not my picture

4 minutes ago, alacant said:

Unless you simply want to photograph the moon and bright planets, imaging at 1000mm focal length is challenging enough as it is. Using a Barlow will not only make the task more tricky, the results you obtain are unlikely to be anywhere near those which you would obtain with the correct adaptor.

Cheers

Ok thanks well these are the things I didnt know. I didnt know that I didnt have the correct adaptor. I will try it at 'prime focus' next time.

2 minutes ago, david_taurus83 said:

The stock focuser left very little room for inward focus. So some people modify the tube by moving the mirror up so the focal plane reaches the camera sensor. Others, like myself, fitted a lower focuser. I've never used the PDS focuser like you have so I cant comment on it.

I think the reason your not getting the answer on the barlow question is because it's not really 'the done thing' . By increasing the focal length to 2000mm you are really going to struggle to frame and image anything. Even 1m is quite demanding. But of course, it's entirely your choice what you do with your own kit and fair play if you can get some nice pictures. People commenting saying try the t adapter are only trying to help and make things easier for you.

Thanks, good info.

I have taken nice pictures with the barlow in place because even tho it is a 2x barlow I dont think it is working at 2x. The spacing from barlow glass to camera sensor is probably different to a normal eyepiece so it would be difficult to work out exactly how much the barlow is affecting the magnification.

This picture is using the barlow lens and dslr...

Ok great,

Thanks for all the replies, shame the sky isnt looking good enough to try it out.

Will post an image on here if it works.

👍

50 minutes ago, david_taurus83 said:

I'll take your word for it as it's your scope! I had the old blue tube and I had to fit a low profile focuser for my 600D.

 

There is a whole host of people online modifying their 200p just so a dslr will reach focus.

2 minutes ago, Cornelius Varley said:

The standard 2"/1.25" does focus with a DSLR, its called a direct DSLR connection

It might have been helpful if you had mentioned that earlier.

The t-thread is M42x0.75mm. I don't think many do have problems, the standard focuser on the 200P allows a camera to reach focus.

Not with the standard 1.25 inch focus tube it doesnt. It's quite well discussed on astronomy forums.

4 minutes ago, CraigT82 said:

Using the Barlow lens on it's own should give you less of a magnification increase than using the whole Barlow.

The further away from a Barlow lens you get the greater the magnification increase. 

So of I can thread straight onto the focusser that will be my minimum magnification?

Then half barlow

Then full barlow lens will be most zoomed in (highest f number)?

2 minutes ago, david_taurus83 said:

Because your doubling the focal length and effectively making it f10. What are you trying to take pictures of?

So you're saying that all 3 methods should be able to achieve focus. And that it will give me 3 different magnifications?

So all these camera t rings are a standard 2 inch thread?

Thus should go straight onto my focusser?

Why do people have issues with focussing a 200p and dslr then?

25 minutes ago, Cornelius Varley said:

@miguel87 What type of focuser do have on your 200P. The standard focuser supplied can take either 2" or 1.25" eyepieces depending on which eyepiece adapter is attached. Removing the adapter reveals a t-thread on the other part to allow a DSLR to be connected.. Can you upload a photo of the telescope showing a close up of the focuser so we confirm the type of 

Which way would you do it...

24 minutes ago, david_taurus83 said:

I'll take your word for it as it's your scope! I had the old blue tube and I had to fit a low profile focuser for my 600D.

A bit confused though, is it the 200p in your profile photo? The one with the dual speed focuser? I thought that these only came on the 200PDS or have you fitted it yourself?

 

Fitted the dual speed Crayford myself.

People saying I dont need a barlow I need a T ring to EOS or something. Why would I buy something I dont have instead of using a barlow that I do have?

Just wanted to know out of my 2 options, not buying any extras, is it better to use whole barlow or half barlow.

Sorry just trying to simplify things 

Ok people,

Fact 1, you CANNOT focus a 200p with a camera attached because the physical length of the focusser is wrong. Therefore,

Fact 2, I HAVE to use my barlow and I know it works perfectly fine and I have a few good photos. The way I think of it is that the barlow reaches down the focusser and grabs the image to bring it all the way up to the camera sensor.

I just wondered if anybody would recommend having the WHOLE barlow attached and having it slide onto the camera nose piece just like it would a normal eyepiece OR take just the little screw off lens from the barlow and thread it directly into the camera's nose piece thread.

6 minutes ago, Shooting star said:

Good thought. Sounds wise. Surprising the relatively little spend required. Which brands are you happy with?

I use vixen SLV for short focal length, bit pricier but worth it, I have a starguider which are endlessly popular and cheap, a vixen nPL which isnt perfect but a step up from supplied eyepieces and one 2 inch sky watcher panaview which I think is underrated.

1 minute ago, alacant said:

Hi. yes. No need to use a Barlow; the quality of your images will be worse. 

Much better to attach the camera directly to the telescope. Unscrew the eyepiece holder first. See here for details, but send a photo anyway. You may have the wrong adapter.

cheers

I think I am not explaining myself well. I have my telescope and camera attached to each other and they work fine with the correct adaptor.

As somebody has informed me, I cant get focus with the camera without using either the tal barlow 2x or the barlow screw off lens 1.25x on it's own.

So now I wonder which of these two options is best to use or if it makes no difference.

12 minutes ago, scitmon said:

You won't achieve focus with standard tube length of the 200p unless you use a barlow.  This is what the 200 P-DS is for: https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200p-ds-ota.html

Thanks. I guess I was lucky that I had the tal barlow then. 

Does it make a difference if I slide the whole barlow on or just use the screw off lens? If so, which is better?

Mike

Ok, you dont want to be disappointed with a cheap scope. It would be worse to be disappointed with an expensive one!

That's why it is worth getting an idea of what the views will be like through any given telescope. Observing is a skill, it's not like looking at a photograph. It's not possible to just spend a grand on a telescope, chuck it up in the garden and have great views.

Will do when I get a chance in a couple of hours. What do you mean about probably having the eyepiece adaptor attached? That's the only way of connecting my camera to the telescope?

I have minimal expectations for AP.

I am primarily interested in observing but every now and then I like to take a photo.

I have a driven EQ5 with a 200p (f5).

When I pit my DSLR into the focusser with T ring adaptor I can only achieve focus if I also screw the Tal barlow lens (the removable bit you can use for 1.25mag with eyepieces) into the end of the camera adapter.

I'm thinking that essentially I am turning an f5 (good for AP) into something slower just to achieve focus..

Can I avoid this without putting money into AP? It's a road I dont really fancy starting on.

Thanks

Umm ok.

Have you ever looked through a telescope before?

What are hoping to observe? Do you want to take long exposure photographs? Where will you store your telescope and will you travel with it or observe from home?

A 12 inch reflector is not best. A 120 inch would give better views. My point being there is nothing special about 12 inches. 

Why do you want an automatic? Theres so much enjoyment to be had in delving into the sky, exploring, searching, finding, getting lost! You wanna spend two grand on a giant telescope that you dont know how to set up? It will just automatically roam around the sky, and point at an object for you to..look at.

Would you know what object to ask it to search for? 

Even if every stargazer in the UK signed the petition it would make NO difference. Space X answers to US agencies not online petitions and there is alot of money to be made. It will also push advances in satellite thruster technology and the falcon launch rocket. Private businesses like space X need to be actively developing if we are going to make it to mars in my lifetime.

Also as said above it is not pointless. Oh the irony of so many people complaining about starlink on an online astronomy forum.

I'd rather it wasnt happening but I can totally understand why it is. Imagine the uproar when thousands upon thousands of monstrous metal electricity pilons were built criss-crossing the entire green countryside of the UK. But we wouldnt live without that network now, our day to day lives are built around it.