What is Wide-Field

[Blackware]

I'm pretty new to this and i'm reading some posts about 'widefield' setups, and scope's that are very good at capturing wide-field.

Google couldn't really help me further so I was wondering what it really meant.

I'm guessing it has something to do with capturing a lot in 1 image ?

Thanks in advance!

[TerryMcK]

3 minutes ago, Blackware said:

capturing a lot in 1 image

That's right. Objects like the North America nebula can completely fill a frame and "wide field" refractor scopes are normally 50 to 70mm aperture with focal lengths from 200 to 430mm.

Edited May 23, 2020 by TerryMcK

[Blackware]

23 minutes ago, TerryMcK said:

That's right. Objects like the North America nebula can completely fill a frame and "wide field" refractor scopes are normally 50 to 70mm aperture with focal lengths from 200 to 430mm.

Thanks for explaining!

[Louis D]

Some folks just use photographic lenses for wide field imaging instead of telescopes.  Others stitch together multiple frames to create wider panoramas.

[jefrs]

Something I'm always trying to get my head around too. Also complicated by the eyepiece because they can vary in field of view as well as focal length,  obviously a long eyepiece will give you a wider FoV than a short one.  A camera will also change the FoV, sensor size (crop factor), whether on prime focus or eyepiece projector.

This calculator may help https://astronomy.tools/calculators/field_of_view/

 

[ollypenrice]

There's no hard and fast definition and there are two worlds, visual observing and astrophotography. What they tend to have in common is that 'widefield' means 'a large swathe of sky containing several or many objects,' as opposed to a field of view featuring a single object. In truth the terms overlap.

Olly

[cloudsweeper]

Say about 3, 4, or 5 degrees of sky might be thought of as wide field.  It is achieved with:

# a short focus telescope - 480, 600mm for example,

# a long focal length eyepiece - say 20mm or a lot more,

# an eyepiece with a large AFOV (apparent field of vision) like 72, 82, or 100 degrees.

Wide field viewing can be very pleasing for framing objects.  It is also good for taking in objects which themselves are large.  And it helps with finding your way around the sky.

Doug.

 

 

Edited May 23, 2020 by cloudsweeper

[maw lod qan]

It can also be as simple as using a camera to image as much of the sky as possible, including constellations or the Milkyway. 

I image a lot like that in hope of capturing a meteor as it streaks across the sky.