Product Description
This is an adjustable 42 mm extension tube that adds 8-12 mm of length. Thread is the standard 1.8" filter thread size of M42 X .75. The depth of the male thread is 8.3 mm and there is a thin (1.72 mm) threaded locking ring on this thread to adjust the spacing. The female thread is 5 mm deep. The body is 1.8" in outside diameter.
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42 MM Variable Extension Tube - Brilliant
This is high quality and very useful extension tube to adjust astro-camera backfocus. Sometimes nominal dimensions are not what you measure with a caliper and this unit is the answer.
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42 mm Variable Extension Tube - 8 - 12 mm Length - SFE-M42-V
Beautifully made, high quality. Unfortunately at an 8.6 mm extension the male threads protrude too far into my filter wheel so I can't use it. I will keep it though for future use.
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Precision Made - You can't go wrong doing buisness with Stellarvue
I was in need of help to arrive at 55 mm of back focus so I called Stellarvue and talked with Vic (owner) he spent considerable time with me on the phone calculating exactly I would need given my different cameras and filter wheel combination. Great support - the extenders, variable
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Precision Made
I was in need of help to arrive at 55 mm of back focus so I called Stellarvue and talked with Vic (owner) he spent considerable time with me on the phone calculating exactly I would need given my different cameras and filter wheel combination. Great support - the extenders, variable
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Allows fine adjustment to spacing
The SFE-M42-V variable length extension tube allows me to achieve perfect focus with my Orion thin off-axis guider and a ZWO ASI120 guide camera. Before using this product I bought several fixed length extension tubes but was never able to achieve proper focus, and it was more expensive and frustrating. This product did exactly what I expected it to. It allows me to fine tune focus very easily. I would highly recommended it to anyone with similar needs.
