Re: [M]: barlow magnification
| Subject: | Re: [M]: barlow magnification |
| From: | ken milburn |
| Date: | Sun Jan 04 08:34:25 1998 |
g. n. paleologopoulos wrote:
>
> Hi people.
> I have the MEADE No 140 2x barlow which I use with my 10" f/10 SCT.
> Is there a quick way to find the barlows true magnification??
> I dont need high accuracy, ballpark is fine.
> Appreciate any responses.
> Happy New Year!!
Hi George,
2X. Seriously, you could try doing a little eyepiece projection
photography on an object(s) of known angular size / separation. Take a
shot without a barlow and then take a shot using the same set up and
include the barlow. Then measure the size of the object on the
negatives. The object you photograph does not need to be an astro
target. Two lines on a piece of paper placed at an appropriate distance
in broad daylight would work good.
If you have access to a nice reticle eyepiece with gradicles for
measuring things (Celestron and Orion offer them) you could do the above
visually and skip the photos.
Best Regards,
Ken Milburn
http://home1.gte.net/kmilburn/index.html
>
> Hi people.
> I have the MEADE No 140 2x barlow which I use with my 10" f/10 SCT.
> Is there a quick way to find the barlows true magnification??
> I dont need high accuracy, ballpark is fine.
> Appreciate any responses.
> Happy New Year!!
Hi George,
2X
photography on an object(s) of known angular size / separation. Take a
shot without a barlow and then take a shot using the same set up and
include the barlow. Then measure the size of the object on the
negatives. The object you photograph does not need to be an astro
target. Two lines on a piece of paper placed at an appropriate distance
in broad daylight would work good.
If you have access to a nice reticle eyepiece with gradicles for
measuring things (Celestron and Orion offer them) you could do the above
visually and skip the photos.
Best Regards,
Ken Milburn
http://home1.gte.net/kmilburn/index.html
