SVBONY Extension Tube M42x0.75 on Both Sides Length T2 Extension Tube Kit Length 5mm 10mm 15mm 20mm

Great quality and value. Unfortunately, the 5 mm and the 10mm are stuck together. I tried filter wrenches to separate them, which didn't work, so I wrapped them in tape and used pipe wrenches, but that still didn’t work. I will assemble everything tomorrow that I purchased it for, and we will see if I need them separated. I also bought the Variable Extension Tube, so I hope to use it to achieve the precise length I need. Just an update SVBONY reached out to me offering a refund on this product. I was very impressed. I planned to order another set and a few other items they make because the quality and value are very good, and that gesture made me a definite SVBONY customer.

These extension tubes screw right onto the celestron T adapter that fits onto the .7 focal reducer. Nicely machined, very happy now that I've achieved 105 mm of backfocus. Great value. Also my new ZWO ASI 294 screwed right onto the T adapter. Edit...... Dont let them get stuck together, using channel locks to get them apart destroys them. Store them apart. You may find you need to paint them inside with a flat black paint. They seem to be glossy and I have had an issue with reflection. A quick spray fixed that.

Seems well built.

The "features" list of the template have no applicability here! Front and Rear Threads do not align properly The aluminum rings are well made and anodized. The screw threads are clean and smooth. There are two down-sides: * The insides of the rings are grooved to reduce reflections, but still too reflective. I may spray paint with matte black. * The threads are not "synchronized"; i.e. the orientation of a camera is not preserved if a ring is added. This requires a major adjustment of something else. The comments are same as those I made for the 8, 25, and 45 mm set of SVBony tubes. This set (5, 10, 15, 20 mm) is more convenient, but spans a narrower range.

On too many occasions, I've needed one or more of these extensions to reach proper backfocus for astrophotography. This set of extension rings is a small investment that will easily pay off over time.

These added just the right extension for my Sony NEX6 on a Celestron Nexstar 127slt telescope to be able to focus the camera. Inexpensive solution to a focusing problem. The picture is of the full moon - horribly bright so it makes it hard to see details on the moon's surface. You may want to scuff the inside to avoid stray light reflections. I didn't have that problem, though.

They work perfectly and priced more than fairly. No regrets whatsoever w/ the purchase. Fast delivery.

Few things everyone needs to take into consideration with these extensions. 1) The lengths are not exactly what is listed. Expect them to be anywhere from .2-.8 mm shorter. This is critical if you are trying to get the correct backfocus. Being off .5mm will cause issues with your images of stars. 2) The outside & inside are painted a gloss black. Get a better brand (and spend the money) to get ones with a flat black interior. These will reflect light in your imaging train.. 3) More important....The threads are not always good and sometimes they dont even screw to each other. This can lead to them being stripped out and worse, make it impossible to remove from each other. Keep in mind, you get what you pay for. While these will do an OK job, make sure you go in with your eyes wide open and you know what you are getting.

Perfect for my needs to get a better focal length for astrophotography

It stays loose at the end of threading. Threads perfectly on my Player One though

Hace exactamente lo que se supone que debe hacer, es un espaciador. La mayoría de las reseñas de una estrella para este producto son erróneas, ya sea por error del cliente o por desconocimiento de su uso. Esto hace exactamente lo que dice, es un espaciador, también necesitarás comprar un soporte helicoidal. y un soporte en T para su cámara que se adapta a su cámara. Vendido por la misma empresa facilita mucho las cosas. 1. El espaciador acercará el plano posterior focal, pero 2. el soporte helicoidal lo ajustará perfectamente. [La revisión que dijo que esto no funcionaría porque no es precisa solo habla de 1/3 de la solución, nuevamente ignorancia y falta de comprensión óptica.] 2. La rosca y el diámetro también son otro factor a tener en cuenta; nuevamente, las revisiones que decían que estos no se atornillarían en su adaptador no observaron correctamente dos números. a. el diámetro b. el ángulo y la resolución del hilo. Ejemplo para este producto... M42X0,75 mm si su configuración es M42x0,80, ¡no funcionará! Ambos números tienen que coincidir. Entonces, para terminar, necesitará los espaciadores, la montura helicoidal y una montura en T para su cámara, y que TODOS los elementos coincidan con el diámetro y el ángulo/resolución de la rosca. Si compras ambas piezas con el soporte en T, se venden, por lo que TODAS las tres piezas juntas FUNCIONARÁN. Si mezclas y combinas, ¡debes comprobar que TODOS los números coincidan y se alineen!

Ideal para extender el back-focus en roscas M42

Très bon produit mais il faut savoir que chaque caméra a des grandeurs différentes pour ses tubes optiques. Pour cette raison j’ai retourné les tubes d’extension qui n’étaient pas compatibles avec mon équipement.