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pleiades

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Everything posted by pleiades

  1. You are welcome Eric! About Miyauchi 100mm collimation screws, must be inside the binoculars below eyepieces as APM 100mm binoculars. It's not very difficult to align them. You just have to open one eyepiece at a time, adjust screws and cover with the eyepiece again to check the alignment. I am not sure if you will lose the Nitrogen filling. Any way the best thing will be to give us a report about it, and take and upload here some pictures, to help others.
  2. Hi Themos! I'm glad you are trying a comparison between different methods and test them. I had experimented with laser beams for collimation in various ways, and also in the manner you describe. Try it out and when finish tell us about the results, so I will describe my experience with laser beams in the past, and the effort for conditional alignment through them.
  3. Some binoculars like Fujinon, use 'eccentric rings' for collimation. Some older, use screws which lay inside the prism compartment. Find the adjustment and the fix screws. More: But usually at most binoculars the adjusting screws are outside of the barrels.
  4. Where the adjusting screws are? Pick up a little the outside material to uncover the screws. Use a jeweler's screwdriver. Celestron Skymaster Helios Quantum 4 United Optics BA8 (Helios Apollo, APM HD, TS Marine, Oberwerk Ultra etc) * Do not touch the screw marked with the yellow circle. Image on top, the screws on Vixen Ultima 9x63 Nikon Action (hex key, Allen key) Bresser 10X50 (Lidl) As you can see most binoculars has the screws in the same position. Do you have more pictures to upload?
  5. I'll just try to add here my experience from tripod ball-heads. I don't feel very comfortable with any handle on the tripod head any more, and I stopped using them. Especially I didn't like that it is near my chest, face, or I had to reverse the handles. Reversed, was difficult to control them. For long time I am using Vanguard SBH-300 & SBH-250 ball heads. Both are very good and easy to use with all binoculars. Can handled from 10X50 to APM 100 45 deg of 7.5 kg aiming to the zenith. With the appropriate tension on the 3 control knobs, work very smooth like fluid heads do.
  6. Excellent article and wonderful pictures! I don't remember if I have seen something so nice written on the Internet.
  7. Steve, Manfrotto's specifications are for 4,5kg. Usually I load up to 2,5 kg with easy. I also have tested it, with 4,5 kg and was OK. But I have never observed all night long with this weight to see if there are weaknesses . I believe if somebody wants to load a little heavier than 4,5 kg can improve it, using a metallic blade to support more weight, like this in the picture.
  8. Hi Alan. At summer I usually spend some weeks near the sea and I like to observe sometime all night long. Trying different set-ups of tripods, parallelogram with tripod and weight, monopod etc, and after some years, I have reach a conclusion and I use a Manfrotto Double articulated arm and a beach lounge chair with success! - The articulated arm: 396B-3 Manfrotto 396B3 Double Articulated Arm, 3 Sections - with Camera Bracket - I also use a Super clamp to securely mount it on the chair: Karlu Photographic : Manfrotto Super Clamp 035 [035] - £22.46, Bowens, Colorama, Interfit & Lastolite Pro Dealers - and a ball head for smooth movements. Because of the lounge chair inclination I observe at zenith with no pain at neck. And no more tripod, weights and heavy equipment. Map, red light, and you are ready for hours of effortless observation. And a sleeping bag just for a short nap under the stars, later!
  9. I can confirm that it also works with inkjet transparencies. It took me only one minute to cut the outside with scissors. Brilliant idea! Thank you again Steve for the advice
  10. First I like to thank you Steve for the great idea you have to use inkjet transparency!!! I didn't tried it yet but this was my purpose when I first asked if we can find any improvements in the procedure. Collaboration is a great thing. Yes, you have right. As I can see if we want to test with a street lamp must be hundreds meters away and strong, so to be as crisp as it can and create spikes. But never will be as good as a star. Those are good news! Your description is very accurate Steve. Of course because I am a little "sensitive" with miscollimation and usually I spend hours in observation, I am trying to fix also small misalignments to avoid fatigue. But this is something personal and everybody can have different tolerance in miscollimation. To tell me how easy is the conditional alignment with the "crossed Bahtinov" technique will be a precious information. For me is easy to align my binoculars this way, and I hope also to be for you all. As regards the name I thing you have already found a descriptive name better than I can! Mark, Peter (Psychobilly) has right. I use Bahtinov mask when I test binoculars. Before some days I tested an Helios Quantum 4 20X80. I found a matter with the width of focus, and was not easy to tell if I was at the right focus for the test. Using a Bahtinov the problem solved easy. Thank you all for the time you have spend already to this. I will be glad if somebody else will try it and review it.
  11. Thank you for the warm words! I hope you will find the time a cloudy night to make 2 masks from paper and review it on another clear night. I have to know if you propose some improvements, or if it was easy for you too to find miscollimation and/or fix conditional alignment. Try it, you will not regret it.
  12. Good question! Because I observe stars, usually I test collimation with stars. But for just checking the method here, of course you can use an artificial star as far away as you can, or farther a pinpoint strong street light, or farther away a star. The only thing we need is the light source to be bright enough to create spikes. In any case at the end check with a star. But to adjust collimation definitely use a star.
  13. Easy and simple! Never thought about this. I suggest to include a lot of info like this in your site Steve, which is difficult to find elsewhere. Thank you for the tip.
  14. Hi David, I don't know if there is an accurate method without opening the binoculars and measure the light path through prisms. Anyway to create a Bahtinov mask for this test, it is not necessary for the focal length to be very accurate. So for a general measurement, we can measure A) the length from the center of objective to the eyepiece. Then measure approximately the length of light path through the prism. (Must be something around 90mm for 8X40 - to 130mm for 20X80. Divide the light path through the prism length by the glass refractive index of 1.57 i.e. for a 130mm/1.57=82.80mm. When these two measurements A) + added together, is the total focal length of the binoculars. I have to repeat here that the accurate number is not necessary. And unfortunately, I don't know an easier method to measure the focal length in binoculars. One more example A) measurement is 160mm for a 10X50. is 100mm/1.57= 64mm A+B=224mm this is the focal length of those 10X50 binoculars. I hope I didn't make it very complicate. @Moonshane @Rik Thanks
  15. Thank you Steve. I will wait for the results. Pm me if you need anything to explain. And don't forget to print from your browser so the the print scale to be at 100% and not to "Shrink to fit", so the dimensions prints at right size.
  16. Hi Steve Congratulation on your site and for your time you've spend! I hope you will enrich soon with more topics. I have put in to my favourites.
  17. Hi Everyone. I have devised a quick way to check binocular miscollimation but also to conditional alignment binoculars and I would like to further field-test the procedure with more people. We have had preliminary tests of this alignment procedure submitted by individuals and the feedback looks very promising. There may be some points of deficiency in this procedure that we currently cannot see and will need to be addressed. I would appreciate hearing from other individuals who have used this procedure and to hear what results they obtained. Can somebody try and review the procedure, to indicate if it's was easy for you to find misalignments errors or the need for some refinements? Please, I must ask, to stay on subject and not make a general conversation. I am interested in the test results and of any improvements in the procedure. Advantages of Bahtinov mask for collimation: It is simple! You can test it using a star, which is the best method for checking collimation by yourself. Or you can use street lights. This method not only lets you know if there is a problem, but is also a very good method for conditional alignment your binoculars. Having tried different techniques over the years, I have never achieved total satisfaction from any of them. For example, using the "relaxed eye method", eyes have the tendency to accommodate for misalignments. So sometimes it's not that easy in locating the misalignments. Especially for horizontal misalignments, where eyes work better and fast to eliminate the problem, finding the error is a pain. The "defocus one eyepiece" method, although it is the most easy and reliable, has a small disadvantage. Eyes try to accommodate the problem if this exists, and the star in focus looks like "fishing around" the defocus image. Furthermore we have noticed that this is dependent of the eyes position on binos axis. So sometimes you are UNCERTAIN if a problem exists or not. With Bahtinov mask, You can observe even the small divergences of vertical and horizontal miscollimation, because of the spikes addition. You can tell very easy, what is the problem, Vertical, Horizontal or both? Especially when you want to fix small aberrations of miscollimation. Bahtinov mask spikes reduce the tendency of eyes to accommodate for misalignments. When eyes are trying to accommodate, spikes are easier to separate. Eyes CANNOT accommodate the misalignments EVEN IF YOU TRY HARD. And this is the advantage from the use of the mask. How to test: As it costs nothing, download a mask just to give it a try, using parameters only for Aperture and Focal Length, from: astrojargon - Bahtinov Focusing Mask Generator: Version 0.4 - First print out 2 copies of the generated file from your browser on a paper, cut it, and uses a rubber band to hold it in place. - Turn the second mask vertical 90 degrees in relation of the 1st mask axis. Then watch the diffraction spikes pattern around a star or a strong long distance street light, and adjust the focus. That's it! If you see one star everything is OK. If you see two stars then you have a miscollimation problem. You can find even small misalignments in collimation. Using a small screwdriver turn the appropriate screws (usually 2) to adjust the prism until the two stars overlapped and see only one star. It is an easy way for conditional alignment of your binoculars. In the photo I used a laser cut mask and one from paper. You can make both from paper (or from inkjet transparency as you will read at the end of the page). Also use a tripod. 1. First focus each eyepiece. Sirius through the Bahtinov Mask. At left, the image is out of focus. At right, the star is in focus. 2. If you see two stars separated you have a collimation misalignment. Using a small screwdriver turn the appropriate screws to adjust the prism. 3. Closer but not in center yet. 4. Dead center. Conditional collimation is OK. As I said, I am interesting in the test results and any improvements in the procedure will be helpful. Try it, I hope you will find it useful. You will find small misalignment that you did not know you already had.
  18. Michael congratulations for your very nice job. - I would like to ask how stable it is? I mean when you touch the mount to change position and aim at a star what is the time needed to calm from vibrations? Can you measure it? - Where is the source for most of vibrations? (In the connection with tripod or at screw conjunctions etc) Thank you
  19. Hi! Anyone knows what is the max Kg load for this tripod? Curiously they not mention it at specification, isn't it? Thanks
  20. Hi Ant Do you own any Ethos to say how is, comparing ES100 for you?
  21. Βy declaration of Sky Quality Meter manufacturer Anthony Tekatch, the highest measurement until now, is this of the observer from the Sahara at 22.15 . http://www.unihedron.com/projects/darksky/database/?allreadings=true This measurement looks real without any excess. Higher than this, means perhaps the need for recalibrating the instrument.
  22. Clusters are a very interesting aim for binoculars. Last October with comet 103P Hartley 2 in the area of Perseus Double cluster , was spectacular.
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