HELP - cannot get image in focus using my Canon

[Bodger]

Hello. I wonder if you can help me? I am trying to take pictures through my ‘scope but cannot get it to focus properly.

To start with I bought a T-Mount and attached it to my 80D then attached it to where the eyepiece is installed.  I extended the ‘scope focus through the entire travel and wasn’t able to get a view in focus.

I read about using a Barlow lens but the T-mount wouldn’t fit it so I then bought a T-Mount Adapter (see link below) and still couldn’t see anything that was remotely in focus until I attached the combo to a Barlow lens and it finally gave me an image - of sorts - of a tower some distance away.

The image is pretty dark and very ‘soft’ and nothing like as clear and sharp as I was hoping for.  Also, because of the high magnification, the slightest touch of the ‘scope makes the image wobble whilst trying to get the image sharp is just awful.  There is very little tolerance between it being in or out of focus.  I have to say that I am very disappointed and was hoping for a much sharper image.

I was also expecting to be able to use different eye pieces but that doesn’t appear to be possible.

Whilst I have been a photographer for many years I am new to astrophotography and so far I’m pretty despondent.  Can you cheer me up?

Telescope: SkyWatcher Explorer 130M; D:130; F:900

Camera: Canon EOS 80D

T-Mount

T-Mount Adapter https://tinyurl.com/y5llubss

[uhb1966]

Hi Bodger!

Well, the wobble is , im afraid, nothing you can do a lot about.

Regarding the dark picture: darkness is a function of the scopes aperture and its magnification, ie the more mag, the darker, the larger the aperture , the brighter.

Regarding the softness: how far is the tower from you, and how is the seeing today? for a test, you might want to try a target no too far away, like 1-2 miles...

[teoria_del_big_bang]

There are issues getting a normal SW 130M to focus with a camera attached. Usually people by the 130 P-DS that has a much shorter tube length when used for astrophotography. 

What is involved to be able to do this with the 130M I am personally not sure but hopefully someone here can help you.

Steve

[Bodger]

28 minutes ago, uhb1966 said:

Hi Bodger!

Well, the wobble is , im afraid, nothing you can do a lot about.

Regarding the dark picture: darkness is a function of the scopes aperture and its magnification, ie the more mag, the darker, the larger the aperture , the brighter.

Regarding the softness: how far is the tower from you, and how is the seeing today? for a test, you might want to try a target no too far away, like 1-2 miles...

Thank you for the reply. The tower I initially used was in the far distance and in bright sunlight I guess maybe 4 or 5 mikes away? I do have another tower much closer which I could try.

Regarding the wobble, I can use ‘live view’ and a cable release so that shouldn’t be too much of an issue I guess.

I think my main concern, and disappointment, is the apparent inability to get a nice clean and sharp image. It could be the ‘cheap?’ Barlow lens that came bundled with the ‘scope? Although I’m a bit concerned at throwing even more money at this without a fairly high chance that it will improve things.

[Bodger]

38 minutes ago, teoria_del_big_bang said:

There are issues getting a normal SW 130M to focus with a camera attached. Usually people by the 130 P-DS that has a much shorter tube length when used for astrophotography. 

What is involved to be able to do this with the 130M I am personally not sure but hopefully someone here can help you.

Steve

Thank you for the reply. Yes the tube length from eye piece to camera body seems pretty long and is obviously not that stable. I would consider changing to the 130 P-DS if I was able to get some form of good feedback that it was the way to go.

I live in Germany and don’t speak the language well enough to have a discussion in a telescope shop 😉

[dobblob]

Images of terrestrial targets on the horizon in any scope are rarely a good test. The thermal disturbance will ruin the view on the best of days.

The moon is now well positioned and this will probably be the best object to judge your telescope on.

[Bodger]

23 minutes ago, dobblob said:

Images of terrestrial targets on the horizon in any scope are rarely a good test. The thermal disturbance will ruin the view on the best of days.

The moon is now well positioned and this will probably be the best object to judge your telescope on.

Yes that’s a good point with the heat haze and all. Thank you.

[Rusted]

I've been through exactly the same steps recently trying to get a  prime focus image out of a spotting scope using a Micro 4/3s camera and then a ZWO astro camera.
The scope just doesn't throw the image out far enough to reach a camera sensor. I bought several camera adapters.
None of them was remotely as long as the one in your link! They were only 35mm and 19mm optical length. With camera bayonet attached.

Like you, I detested the effect of adding a Barlow or GPC. The power [equivalent focal length] was so high it was utterly pointless to continue.
I was eventually able to focus on 100 yard distant objects but nothing beyond. Far too high a magnification and too dim an image.

What you could try is afocal photography. Also known as "digiscoping:"
You use a low power eyepiece and mount the camera beyond that. With or without a short semi-wide angle, camera lens.
I use a 20mm f/ l.7 pancake lens in the camera. The camera itself hangs from the lens' filter thread via a T2 > camera adapter. [See image.]

Better camera shops should have these shallow/short adapters. Some of the adapters I tried were unique to the spotting scope so not relevant here.
Browsing through camera adapters on an astro sales website should throw up something which fits over a 1.25" eyepiece to support the camera.
It will need clamping screws to grip the eyepiece body. I'm on my imaging laptop so don't have access to all my pictures.

A final note: When testing for distance focus:  Point the telescope at something very close until it will reach focus.
Then work your way slowly into the near distance to discover where it does continue to focus sharply.
In my case it was only a few yards away! Everything beyond that was always out of focus.

 

Edited August 1, 2020 by Rusted

[Aramcheck]

The EQ-2 mount also isn't good enough for general Astrophotography use, though you may be ok for Lunar images. To photograph deep sky objects you need a good solid mount which can be polar aligned accurately & which had very good tracking, so you can take long exposures without star trailing.

When we started out with an EQ-2 130M, I made a wooden adapter so I could replace the scope with a camera and a findershoe attached to a piece of wood. You might find something similar would be ok for widefield shots, using your DLSR, though exposure times will still be limited.

Cheers,
Ivor

[Bodger]

19 minutes ago, Rusted said:

I've been through exactly the same steps recently trying to get a  prime focus image out of a spotting scope using a Micro 4/3s camera and then a ZWO astro camera.
The scope just doesn't throw the image out far enough to reach a camera sensor. I bought several camera adapters.
None of them was remotely as long as the one in your link! They were only 35mm and 19mm optical length. With camera bayonet attached.

Like you, I detested the effect of adding a Barlow or GPC. The power [equivalent focal length] was so high it was utterly pointless to continue.
I was eventually able to focus on 100 yard distant objects but nothing beyond. Far too high a magnification and too dim an image.

What you could try is afocal photography. Also known as "digiscoping:"
You use a low power eyepiece and mount the camera beyond that. With or without a short semi-wide angle, camera lens.
I use a 20mm f/ l.7 pancake lens in the camera. The camera itself hangs from the lens' filter thread via a T2 > camera adapter. [See image.]

Better camera shops should have these shallow/short adapters. Some of the adapters I tried were unique to the spotting scope so not relevant here.
Browsing through camera adapters on an astro sales website should throw up something which fits over a 1.25" eyepiece to support the camera.
It will need clamping screws to grip the eyepiece body. I'm on my imaging laptop so don't have access to all my pictures.

A final note: When testing for distance focus:  Point the telescope at something very close until it will reach focus.
Then work your way slowly into the near distance to discover where it does continue to focus sharply.
In my case it was only a few yards away! Everything beyond that was always out of focus.

 

 

19 minutes ago, Rusted said:

I've been through exactly the same steps recently trying to get a  prime focus image out of a spotting scope using a Micro 4/3s camera and then a ZWO astro camera.
The scope just doesn't throw the image out far enough to reach a camera sensor. I bought several camera adapters.
None of them was remotely as long as the one in your link! They were only 35mm and 19mm optical length. With camera bayonet attached.

Like you, I detested the effect of adding a Barlow or GPC. The power [equivalent focal length] was so high it was utterly pointless to continue.
I was eventually able to focus on 100 yard distant objects but nothing beyond. Far too high a magnification and too dim an image.

What you could try is afocal photography. Also known as "digiscoping:"
You use a low power eyepiece and mount the camera beyond that. With or without a short semi-wide angle, camera lens.
I use a 20mm f/ l.7 pancake lens in the camera. The camera itself hangs from the lens' filter thread via a T2 > camera adapter. [See image.]

Better camera shops should have these shallow/short adapters. Some of the adapters I tried were unique to the spotting scope so not relevant here.
Browsing through camera adapters on an astro sales website should throw up something which fits over a 1.25" eyepiece to support the camera.
It will need clamping screws to grip the eyepiece body. I'm on my imaging laptop so don't have access to all my pictures.

A final note: When testing for distance focus:  Point the telescope at something very close until it will reach focus.
Then work your way slowly into the near distance to discover where it does continue to focus sharply.
In my case it was only a few yards away! Everything beyond that was always out of focus.

 

Many thanks for the detailed reply. I certainly appreciate it and will investigate further. Thank you.

[Rusted]

FLO has "universal eyepiece adapters" for eyepiece projection which fit over standard eyepieces like Plossls.
The camera side has a T2 male thread. You connect this to a T2 female to camera bayonet adapter.
Their website won't let me copy an image location link so you'll have to search for it.

[Bodger]

Many thanks for the update 😉

[RT65CB-SWL]

44 minutes ago, Rusted said:

FLO has "universal eyepiece adapters" for eyepiece projection which fit over standard eyepieces like Plossls.
The camera side has a T2 male thread. You connect this to a T2 female to camera bayonet adapter.
Their website won't let me copy an image location link so you'll have to search for it.

I think @Rusted means this: -->https://www.firstlightoptics.com/adapters/universal-camera-adaptor-for-eyepiece-projection-astrophotography.html
and quote: "...T2 female to camera bayonet adapter." ...i.e. T-ring for your camera: -->https://www.firstlightoptics.com/adapters/t-rings.html 

Alternatively there are 'eyepiece projection units', i.e. EPU: -->https://www.firstlightoptics.com/adapters/tele-camera-adaptor-for-eyepiece-projection-astrophotography.html - you need the T-ring for this too.

 

[uhb1966]

well,my fellow stargazers beat me to giving you more tips

One more thing: i suggest starting out without the barlow lens and well, using the moon as a target which you know by now - with the moon, you can get by with quite short exposures, that reduce the wobbles

And: if you dive into astrophotography, usually the most expensive hardware is agood mount ... best! U.

[Bodger]

20 minutes ago, uhb1966 said:

well,my fellow stargazers beat me to giving you more tips

One more thing: i suggest starting out without the barlow lens and well, using the moon as a target which you know by now - with the moon, you can get by with quite short exposures, that reduce the wobbles

And: if you dive into astrophotography, usually the most expensive hardware is agood mount ... best! U.

Many thanks for the tip. Much appreciated 😉

[Bodger]

48 minutes ago, Philip R said:

I think @Rusted means this: -->https://www.firstlightoptics.com/adapters/universal-camera-adaptor-for-eyepiece-projection-astrophotography.html
and quote: "...T2 female to camera bayonet adapter." ...i.e. T-ring for your camera: -->https://www.firstlightoptics.com/adapters/t-rings.html 

Alternatively there are 'eyepiece projection units', i.e. EPU: -->https://www.firstlightoptics.com/adapters/tele-camera-adaptor-for-eyepiece-projection-astrophotography.html - you need the T-ring for this too.

 

Many thanks. Some good information there. Many thanks for the links 🙂