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20x eyepiece on a 883 scope? (1 Viewer)
- Thread starter greg g
- Start date
Roy Halpin
Well-known member
I'm not sure if they interchange, but I will find out
On review and comparison of these two eyepieces;
Kowa TSE-21 WD 20x WA for the 66 series
1. Relative Brightness 10.9
2. Exit Pupil 3.3 mm
3. AFOV 173’
4. Eye Relief 20 mm
Kowa TSE-21WE 21x WA for the 82 series
1. Relative Brightness 15.2
2. Exit Pupil 3.9 mm
3. AFOV 163’
4. Eye Relief 20 mm
How are these specs impacted or changed when attached to the 88 series spotting scope? What is interesting is the relative brightness difference. By looking at these figures is there any logical formula to translate into series 88 specs?
Thank you,
Greg
Kowa TSE-21 WD 20x WA for the 66 series
1. Relative Brightness 10.9
2. Exit Pupil 3.3 mm
3. AFOV 173’
4. Eye Relief 20 mm
Kowa TSE-21WE 21x WA for the 82 series
1. Relative Brightness 15.2
2. Exit Pupil 3.9 mm
3. AFOV 163’
4. Eye Relief 20 mm
How are these specs impacted or changed when attached to the 88 series spotting scope? What is interesting is the relative brightness difference. By looking at these figures is there any logical formula to translate into series 88 specs?
Thank you,
Greg
henry link
Well-known member
Greg,
These are probably both the same 21mm eyepiece design. The spec differences in magnification, exit pupil, TFOV (not AFOV, which is a constant 65-66 degrees) and Relative Brightness simply reflect the differences in the 66mm and 82mm scopes' apertures and focal lengths. On the 88 series (about 500mm focal length) these eyepieces would produce about 24x and the specs would change in response to that.
Relative Brightness 13.44
Exit Pupil 3.67mm
TFOV 143'
Henry
These are probably both the same 21mm eyepiece design. The spec differences in magnification, exit pupil, TFOV (not AFOV, which is a constant 65-66 degrees) and Relative Brightness simply reflect the differences in the 66mm and 82mm scopes' apertures and focal lengths. On the 88 series (about 500mm focal length) these eyepieces would produce about 24x and the specs would change in response to that.
Relative Brightness 13.44
Exit Pupil 3.67mm
TFOV 143'
Henry
Henry,
I did get an opportunity to see these two eyepieces side by side on an 88 scope. They were a little different in profile but when looking thru them I couldn't really tell the difference. I did purchase the TSE-21WE that originally was for the 82 series scope. The adapter for both eyepieces to engage into the 88 makes them a screw-in eyepiece instead of a bayonet style. I compared the FOV with the eyepieces that are made for the 88 series, 25x and 30x, and this eyepiece has a wider field of view. It wasn't a lot enough that I wanted as part of the eyepiece set.
Greg
I did get an opportunity to see these two eyepieces side by side on an 88 scope. They were a little different in profile but when looking thru them I couldn't really tell the difference. I did purchase the TSE-21WE that originally was for the 82 series scope. The adapter for both eyepieces to engage into the 88 makes them a screw-in eyepiece instead of a bayonet style. I compared the FOV with the eyepieces that are made for the 88 series, 25x and 30x, and this eyepiece has a wider field of view. It wasn't a lot enough that I wanted as part of the eyepiece set.
Greg
Greg,
I recently bought an 883 and put my 21we on it and am very pleased. My sony w300 with 3x works the way it should with no vignetting. Before the 21x I had an old zoom and used it most of the time at 20x on an 821 and had to zoom with an effective power about 40x. It is very nice to now have a wider view. It is also nice to focus at 15'-20'.
I recently bought an 883 and put my 21we on it and am very pleased. My sony w300 with 3x works the way it should with no vignetting. Before the 21x I had an old zoom and used it most of the time at 20x on an 821 and had to zoom with an effective power about 40x. It is very nice to now have a wider view. It is also nice to focus at 15'-20'.
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