Zwo Asi 178mm and lunt 60mm

[Nigella Bryant]

Hi all, I bought a new Zwo Asi 178mm for my lunt 60mm. I'd used the field of view calculator b4 I purchased it and it calculated that I'd get a full disk image so I went ahead and bought it about 4 weeks ago. Only just able to use it. I couldn't get a full disk image, only partially. I then used a 0.5 reducer and too didn't provide a full disk image. I've previously been using a zwo120mm usb2 with a 0.5 reducer and this gave me a full image with the lunt. I'm pleased with the difference in resolution of the 178 but what if anything am I doing wrong. I quite savey with imaging equipment so any help would be appreciated. Thanks for reading. 

Edited February 6, 2020 by Nigella Bryant

[michael.h.f.wilkinson]

I get a full disk image on my ASI178MM with my APM 80mm F/6 (480mm focal length), but not with loads of room to spare, the Lunt has 500mm focal length, which might be a bit tight around perihelion (which is in winter)

[Nigella Bryant]

12 minutes ago, michael.h.f.wilkinson said:

I get a full disk image on my ASI178MM with my APM 80mm F/6 (480mm focal length), but not with loads of room to spare, the Lunt has 500mm focal length, which might be a bit tight around perihelion (which is in winter)

That could explain it. According to the field of view calculator I thought I'd have more room for maneuver. 

[david_taurus83]

I'm sure the 178 is a larger sensor than the 120 so confused as to how you can get full disk with the smaller chip but not the larger?

[Nigella Bryant]

22 minutes ago, david_taurus83 said:

I'm sure the 178 is a larger sensor than the 120 so confused as to how you can get full disk with the smaller chip but not the larger?

Yeah, me too, that's what's confusing me. 

[david_taurus83]

What software for capture? Sure it wasnt set to region of interest?

[Nigella Bryant]

OK, this is odd, I've just done a play back of each file and they are full disk. I'd assumed that what I was seeing on the laptop was what was being imaged and not quite full disk. I'm using sharpcap 3.2. I've never adjusted the view on sharpcap. Is there a way to zoom out. At least I now know I am taking full disk image's of the solar disk just not seeing that on the output in sharpcap. 

[Anne S]

What size laptop are you using. I use a Hypercam178 with the Lunt50. It's a very big image because of the small pixels and I need to zoom out to see the whole frame.

[Nigella Bryant]

4 minutes ago, Anne S said:

What size laptop are you using. I use a Hypercam178 with the Lunt50. It's a very big image because of the small pixels and I need to zoom out to see the whole frame.

It's a 17inch wide screen, I think I need to zoom out then. I'd bought the 178 because, a) it's usb3 and b) I wouldn't have to use the 0.5 reducer. So I guess alls well after all. I'll just have to learn the zooming out feature. 

[tooth_dr]

I see you’re sorted!
I have a 120mm and a 178, and a lunt 60mm, and was wondering what you we’re doing wrong.