Vintage Sears Discoverer 60mmPosted By Steve House |
Hi all,
I thought I'd test a newly acquired Sears Discoverer 60mm lens last evening.
But first- when cleaning it last week, I found that the two elements in the lens had no spacers of any kind. That seemed peculiar based on all the 60mm lenses I used to take apart, but then you never know. I put the cleaned glass back together- glass on glass.
So last evening I saw a nicely focused Saturn surrounded by a defocused "ghost" disc of light about 5 times the dia. of the planet. The ghost disc would focus or defocus. At only one place in the FOV would the focused Saturn be centered in the disc, (and it wasn't in the center).
Am I correct that the ghost is a result of not having the two elements properly spaced? Is that spaceing critical? Any suggestions as to what I should use? Thanks!
I thought I'd test a newly acquired Sears Discoverer 60mm lens last evening.
But first- when cleaning it last week, I found that the two elements in the lens had no spacers of any kind. That seemed peculiar based on all the 60mm lenses I used to take apart, but then you never know. I put the cleaned glass back together- glass on glass.
So last evening I saw a nicely focused Saturn surrounded by a defocused "ghost" disc of light about 5 times the dia. of the planet. The ghost disc would focus or defocus. At only one place in the FOV would the focused Saturn be centered in the disc, (and it wasn't in the center).
Am I correct that the ghost is a result of not having the two elements properly spaced? Is that spaceing critical? Any suggestions as to what I should use? Thanks!