Do Binoviewers give a wider field of view?

[davo]

As the title says really.. do they give a wider field of view than looking though one eyepiece?

Also i think i remember someone saying to me that the light is halved. Does this mean the galaxies i often view will be dimmer?

[cantab]

No. In fact they'll typically give a narrower field for two reasons. Firstly the ultra-wide-angle eyepieces are so big you can't fit two side-by-side, even if you could afford a pair. Secondly you often need to use a Barlow or you can't reach focus, pushing up the magnification and lowering the field of view. (But if you have a truss-tube Newt you can just get shorter poles so you don't need a Barlow.)

Obviously each eye gets half the light. This is considerably better than just one eye getting half the light, but when it comes to viewing the very faintest objects it's not quite as good as one eye getting all the light.

[davo]

Cool, very informative thanks for that.

[heavensabove]

No. In fact they'll typically give a narrower field for two reasons. Firstly the ultra-wide-angle eyepieces are so big you can't fit two side-by-side, even if you could afford a pair. Secondly you often need to use a Barlow or you can't reach focus, pushing up the magnification and lowering the field of view. (But if you have a truss-tube Newt you can just get shorter poles so you don't need a Barlow.)

Yup , narrower field of view which is why I tend to use mine on planets and moon as well as doubles .

Using them on the Mak , there is no need for a barlow to reach focus .

Obviously each eye gets half the light. This is considerably better than just one eye getting half the light, but when it comes to viewing the very faintest objects it's not quite as good as one eye getting all the light.

Using them on planets and moon , I find using both eyes to be really relaxing enabling to tease out more details than mono viewing , even on bright clusters , they

can be quite good but I agree when it comes to fuzzies they are not very useful .

[acey]

Field of view is determined by two things: the field stop of the eyepiece and the focal length of the telescope. Field stop is limited by the diameter of the focuser. A binoviewer makes no difference to that. If you wanted to increase the maximum possible true field of a telescope (without changing its objective lens or primary mirror) then the only way would be to make the focuser wider (and make bigger eyepieces, with bigger field stops, to fit).