Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Atik 314L+ versus 414EX

Scott

By Scott
in Discussions - Cameras

Recommended Posts

  • Replies 80
  • Created
  • Last Reply
Chris

Chris

Posted
Posted

Why does it vignette so bad with a DSLR, I have an 1100D to try on it?

Regards

AB

DSLR's have large sensors, and the focuser tube is quite narrow on the WO66. A small chipped CCD probably wouldn't vignette no where near no badly.

Link to comment
Share on other sites
Scott

Scott

Posted
  • Author
Posted

This was taken with an atik 16hr (same fov as the 414ex) on an Altair astro 60mm lightwave (fl 420mm) with a resolution of 3.17" It may not be the best image out there but I'm happy enough with the stars (althou slight trailing).

16201412649_c62d6b4868_c.jpgRosette Ha Stack dark c+l123 by Scott Prideaux 1961, on Flickr

It then gives a resolution of 1.33" with my 8" f5 newt.

16169371956_52010833a5_c.jpgcrab ha process2 by Scott Prideaux 1961, on Flickr

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

Nice demo of resolution :)

Looking at the Bok globs in the Rosette, and the filaments in the crab, plus stars in both images, I do think the Crab image is crisper as it should be. Not a great deal in it though! The Rosette just looks a touch softer to my eyes but its tricky comparing two different objects. Both 3.2 and 1.3 "/pixel look look like they work well :) 

Link to comment
Share on other sites
Scott

Scott

Posted
  • Author
Posted

Nice demo of resolution :)

Looking at the Bok globs in the Rosette, and the filaments in the crab, plus stars in both images, I do think the Crab image is crisper as it should be. Not a great deal in it though! The Rosette just looks a touch softer to my eyes but its tricky comparing two different objects. Both 3.2 and 1.3 "/pixel look look like they work well :)

Never underestimate my ability to ruin an image with my lack of processing skills ;)

Link to comment
Share on other sites
Astroboffin

Astroboffin

Posted
Posted

DSLR's have large sensors, and the focuser tube is quite narrow on the WO66. A small chipped CCD probably wouldn't vignette no where near no badly.

My ZS has a 2" focuser, just has the SCT thread on the end, so my FFR screws straight to that and the DSLR t ring straight onto,the other side, but the focuser tube is way bigger that the DSLR sensor!

You got me worried now as I bought that scope for wide field with my DSLR, I know I will get vignetting if I used it with the 1.25" adapter that comes with the scope, but thought it would be ok without that on.

:(

AB

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

I'll post a pic later demonstrating the vignetting, I just need to re-stack the data first when a get time.

Yes, the scope does vignette badly with a large sensor, but if you are happy to take the time taking decent flats it's of no consequence, so don't worry :) I'm not keen on taking flats but I'm happy with a small sensor so I get round it that way.   

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

Just to put your mind at rest, here is an image of M31 I took in 2012 with my former WO66 plus mk2 RF. This time I took good flats:

Edit: looking at it, it might have been without the RF but still with the WO66. Picture taken from my gallery.

post-16129-0-27351500-1424357678_thumb.p

Link to comment
Share on other sites
Astroboffin

Astroboffin

Posted
Posted

Here we are: WO66 + .8 RF and Canon 350D. Bubble neb and M52 quick stack of 12 x 60 seconds with a quick stretch for vignette demo purposes.

I can only upload as a TIF using this PC apparently, attempt to convert to jpeg failed?

Which Version FFR do you have, the one made for this scope was the version II, but I have the version III which was for,the ZS71 I think bit still works perfectly with the ZS66, (just needsa tad more in focus) I am wondering if the clear aperture is larger on mine that the version II, as that might cause vignetting, just a thought, I like the pictures you posted, very encouraging :)

AB

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

On my first WO66 I managed to bag a mk11, but with my current WO66 I was only able to get hold of the mk3. The Bubble nebula M52 shot was with the mk3. 

The WO66 is a dainty little imaging scope, as you know you can squeeze 2" kit to it via the SCT thread, but a lot of scopes have larger draw tubes which step down to 2", and even more lately fracs have 2.5-3" focusers to help reduce vignetting.

Still the WO66 is a class act for very little money :) 

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

An Atik 414ex or 420L wouldn't show much vignetting on the WO66 at a guess, I might get to find out soon :)

I thought I'd better steer the topic back to the 414ex :D

p.s The m31 shot was taken at 2.75 "/pixel for those looking at resolution.

Link to comment
Share on other sites
Astroboffin

Astroboffin

Posted
Posted

An Atik 414ex or 420L wouldn't show much vignetting on the WO66 at a guess, I might get to find out soon :)

I thought I'd better steer the topic back to the 414ex :D

p.s The m31 shot was taken at 2.75 "/pixel for those looking at resolution.

I thought we had agreed that the 414ex had too bigger pixels for a good image scale on the ZS66, would give around 4.5 AS per pixel.

:)

AB

Link to comment
Share on other sites
Astroboffin

Astroboffin

Posted
Posted

If I wen't that way I would lose the reducer :) The extra sensitivity would offset the slower f/ratio I think?

Also, hopefully the small chip wouldn't show the field curvature?

That would take it from 4.29 arc seconds / pixel, down to 3.43, would that be ok then, as it is under 4 ??

AB

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

That would take it from 4.29 arc seconds / pixel, down to 3.43, would that be ok then, as it is under 4 ??

AB

Hi, It's not that it's not ok if you go above 4 "/pixel, there might be people out there imaging higher than this and happy with the results? 

I've just set the limits of 1-4 based on the reading I've done, and the limited number of images (probably about 30-40 ish) I've taken with various scopes and cameras over 3-4 years.

I'm sure some people out there don't give a hoot about matching cameras with scopes, I feel it's quite a personal thing :)

What do you think about the images posted by auspom? The Rosette with fairly chunky resolution, and the Crab with finer resolution, and my m31 which is the middle at 2.75? This might help you decide how important resolution is to you? obviously there are error bars with processing, but I really like his Crab neb! :)  

Link to comment
Share on other sites
Chris

Chris

Posted
Posted

Another thing, we should probably be considering other factors such as quantum efficiency, well depth, and cooling etc, along with pixel size :)

Everything I've read so far points towards the 414ex to be the one to go for. It also says mono but I might have to be e rebel on that one! 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.