![]() If you are trying to focus on an extremely dim deep-sky object or the field you want to photograph does not have any bright or moderately bright stars in it, some experts recommend you slew the telescope over to the nearest bright star, focus on that, and then slew the telescope back. If you do attempt to focus with your unaided eye through the viewfinder, at least try to pick a star that is not too bright. We can pick a bright star to try to focus on, but the light from a bright star irradiates and spreads in the ground glass of the focusing screen making it difficult to tell when it is in focus. Most screens, which seem quite bright for daytime work with fast lenses that focus with the diaphragm wide open at f/2.8 or so, suddenly seem quite dark at prime focus of an f/8 telescope. The trouble is, with a camera, the image is projected onto the ground glass of the focusing screen first. When we look through a telescope to visually observe we usually don't have any trouble at all focusing the eyepiece, unfortunately the same cannot be said for focusing a camera. It's not that accurate for the bright stuff either. When we get to the faint stuff, we find that it is very difficult to focus this way. It may be easy, but it is not necessarily accurate with repeatable consistency. It would seem that the easiest way to focus is to just look through the viewfinder of the camera and try to focus. Hybrid Method - Star Trails with a Hartmann Mask.The first three are generally the least accurate for truly critical focusing. The following methods are presented, more or less, in a general order of accuracy, from least accurate to most accurate. On the other hand, fast optical systems and high-resolution digital sensors demand critical methods for good results. We can get away with a lot if our optical system has a slow focal ratio. Many of these methods listed below can yield good results if the problems of focusing are taken into account, and the limitations and idiosyncrasies of each method are understood. These different methods range in accuracy from the least accurate - focusing with the unaided eye on the ground glass of the camera through the pentaprism, to the most accurate: examining a star in an actual test exposure with software metrics. The better methods are also more consistently repeatable, which is an important consideration because of the time and effort we spend on our hobby. The > best way is by using magnified Live View to focus your DSLR. Today, the most accurate method of focusing is with Software Metrics, but this requires a computer > to the scope. ![]() Many of these methods were developed during the days of film astrophotography and don't apply to digital astrophotography. r/jigsawpuzzles - Jigsaw puzzles.There are many different methods of focusing, and some work better than others. r/rebus - Visual puzzles where images are strung together to make a sort of visual pun. r/mazes - Visual puzzles where you find a path through the, well, maze. Stuff like "What gets wetter as it dries?" r/riddles - word-based puzzles that use lateral thinking, rather than logic. Reddit Desktop Site (Fancypants editor/redesign): Related subreddits >!The princess was in another castle!!!The guess goes here!! the beginning!!end !< of your spoiler will break it for users on some apps and This rule applies more to puzzles you found online.Īpps,, and the New Reddit markdown editor: If you are not sure of it, or have personally received the puzzle from someone, please indicate that. If you did not make the puzzle, please try your best to credit the original source. If you see a riddle that's part of a contest, please report it.Ĭredit puzzle creators. Please do not posts puzzles from ongoing contests. Titles should be descriptive, not just "Check out this puzzle" or "Puzzles only geniuses can solve." Jigsaw puzzles are best suited to /r/jigsawpuzzles Check out /r/riddles for puzzles based on lateral thinking. ![]() Top level comments are automatically removed unless they include a spoiler tag or start with "Discussion:" or "Question:"Īll puzzles should be logic based. Use spoiler tags when posting a hint or solution to a puzzle. ![]() Generally, videos should promote discussion, and websites should provide features that are useful to solving the puzzle. Posts that make sense as a video or website link are allowed with moderator approval, so please ask us first. Logic and/or math-based puzzles that fit a text or image format are generally allowed. ![]() Links to apps, blogs, and most videos belong in the Promo Weekly post. Self-promotion is allowed only in the Promo Weekly post stickied to the top of the thread. ![]()
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