Magnification appears low through DSLR?

[Heath (Heater)]

Hi all,

I am waiting on the delivery of a mount for my refractor but couldn't help hooking up the full frame canon DSLR to the OTA to check out the magnification. I used a T ring adapter, extension tube and field flattener and when looking through the live view was expecting allot more magnification than what was there. The scope is a 105 aperture f7 and after looking at all the magnificent pictures taken with scopes both larger and smaller in aperture than mine I was wondering how possibly these pics are taken? Do people use barlows? Or am I missing something here?

any help answering this appreciated

Heath

[Merlin66 (Ken)]

The larger CCD allows for a greater field coverage. The scale of the image is related to focal length. The resolution to the pixel size.
Just crop and "blow up" any areas of interest.
The 105 and DSLR is a good combo for nebulae.
Ken

[DavidU (Dave)]

A lot of the planetary fellas use a small CCD/CMOS sensor and long focal length as well as a 5x barlow.

[Heath (Heater)]

Thanks for your replies,

So as I understand it, the CCD cameras open it up a fair bit but the view I can see with the DSLR attached is sufficient magnification to capture nebulae? I understand that stacking is required, but I wouldn't have thought that what I see magnified terrestrially would be sufficient to capture such images.

[mswhin63 (Malcolm)]

Through live view the resolution is reduce by about 10 times mostly because the LCD on the camera is small and the frames rate can be higher during live view. Consequently the image appear small especially when taking planetary. You can set the x5 on and it will increase the magnifacation without changing the resolution. On really clear skies I have managed to get good capture for Jupiter using live view.

[Heath (Heater)]

Originally Posted by mswhin63

Through live view the resolution is reduce by about 10 times mostly because the LCD on the camera is small and the frames rate can be higher during live view. Consequently the image appear small especially when taking planetary. You can set the x5 on and it will increase the magnifacation without changing the resolution. On really clear skies I have managed to get good capture for Jupiter using live view.

So even though the only magnification is over the focal length the imagery once blown up still should be ok? I realise that stacking would be required for nebulae but I don't need to barlow to get decent shots? I did point the scope to Jupiter and you're right, its image looked minute, not much better than through the cannon lens.

[adman (Adam)]

One of the things that I found most surprising when I was starting out was the size of some of the objects. There are some nebulae that are around the same angular size as the full moon - eta Carina etc. It just takes long exposures to make the full extent of them visible.

All will become clear when you start to take a few astrophotos rather than terrestrial photos!

Adam

[Heath (Heater)]

Originally Posted by adman

One of the things that I found most surprising when I was starting out was the size of some of the objects. There are some nebulae that are around the same angular size as the full moon - eta Carina etc. It just takes long exposures to make the full extent of them visible.

All will become clear when you start to take a few astrophotos rather than terrestrial photos!

Adam

Righto! that now makes some sense, thank you. I did get out between the clouds last night and had a quick look at Jupiter through an 11mm. I really want to push the magnification so as to see bands etc (for viewing at least), so any recommendations would be greatly appreciated