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Hey all. I'm fairly new to all this and, as I'm into my photography I've bought some adapters so I can attach my DSLR to my telescope to photograph the moon and our closer planets. Now that the skies have cleared up I managed to get out this morning to try and photograph Jupiter & Saturn. Firstly, WOW! What an amazing, overwhelming sight. I've never seen anything like it before - truely amazing! Something I'd love to document for myself and to share with others. However.... I couldn't  I attached my camera and then it all went black, absolutely nothing was coming up on my screen. I thought I'd done my research. I have the 2 adaptors that attach it and also have an extension tube. I was using a 2x barlow too. I couldn't understand why I can see it through the eyepiece and not my camera. I was manually tracking it (boy do they move quickly! Lol). Am I missing something to be able to get it in the camera viewfinder? I was able to get trees into view during the day yesterday - although they were out of focus. Any ideas, tips & suggestions please?  I have a Meade Polaris 114. D=114mm F=900mm f7. 9 Canon 90D (used with 2x barlow) Thanks in advance. JoJo |
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Hi, The DSLR sensor is about 4-5 centimeters from the focuser. This is a very different place from where the eyepiece goes (2-3 centimeters inside). So it is perfectly natural that when you see something with the eyepiece and the pull the eyepiece off and connect your DSLR you won't see anything. The image is not focused at the sensor. With a Newtonian that is not designated as an astrograph it is very much possible that you will not be able to focus on you camera sensor, it simply isn't capable of sending the image that far outside. Although the Barlow should help in this regard, and if you say you can see the trees (even not very well focused) chances are you'll get an acceptable result. So there goes one of your problems: simply play with focusing until you find the right setting. Typically this means the position of your subject will change too. You see it at the center with your eye but when you achieve focus with the DSLR it will be near the edge of live view. Perhaps completely outside. So you need to move the telescope a little bit to adjust for that. And the third problem is Jupiter and Saturn are very faint to do all that, especially if you are a beginner and don't know your camera/telescope's capabilities. Maybe you need to bump the ISO to a large value. Maybe you need to switch to video. Lots of parameters and it is very easy to miss a faint target which is just a spot. I would aim for something larger, such as the Moon or denser in "spots" (i.e. stars) such as the Sagittarius region of the galaxy. Preferably the Moon as it is very difficult to miss. So: try to get the Moon centered and focused. Mark the position of the focuser. Also try to get the best ISO setting on your DSLR once the moon is focused (not too low as it will barely show up, also not too high as it will be blown into white). Then, you are ready to go for Saturn/Jupiter. If you have the correct position marked you can still use the eyepiece to find the objects and then switch to the camera (note: _some_ adjustment will always be needed, even a millimeter off will ruin your focusing but a marking will at least give you a good head start where the object is somewhat visible). All that said, a DSLR is a bad choice for such targets because its sensor is too large. Chances are even a simple webcam will do much better. Cheers, D. |
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Thank you so much for your detailed reply. I'm hoping to have a play with the moon soon So, would one of those USB cameras that fit onto the eyepiece work better? Thanks JoJo |
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Hi JoJo, If you mean an astronomical camera yes, it will work better. But a webcam will do all right too. Even your mobile cam could do very well if you find a way to attach it. The DSLR will be tricky. Even if the distance to the sensor can be overcome by the focuser, thing is you will be using a very large sensor (5000 pixels across) to project a tiny planet perhaps 50 pixels across. Planets are usually not photographed (it is VERY difficult to get a good single shot of a planet) but captured on video (24-50 frames, that is photos per second) and then you combine the best few hundred frames with a program like registax. So basically you will find yourself capturing hundreds of megabytes of video and only 1% right at the center will be the planet, the data you need. Bit of an overkill. Very tiny for any meaningful detail, too. Of course since you already have the adapter why not give it a try. I've had a lot of fun with my astromaster and the d3300 despite both of them being completely unsuitable for astrophotography. The best Jupiter I was able to capture looked more like a defocused Venus but so what. Cheers, D. |
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dkamen gave you excellent advise. I can only second that. Try to focus distant objects in daylight with your DSLR, scope and barlow. If you manage that and still have a few milimeters of focuser travel left, you'll be good. Then try the moon. Everything is so much easier with the moon... it's just so large and bright. Shoot video, if possible, and use a remote shutter release to make life easier. Then try Jupiter and Saturn. Finding the best focus for those two is - to be honest - challenging. It all happens within a fraction of a milimeter focuser travel. But if everything breaks down, just enjoy the view with your eyepiece |
