Guest Si2504 Posted March 10, 2016 Share Posted March 10, 2016 Hi all, i have noticed some strange artifacts/blotches in some of my images. I don't seem to notice them when using my camera with a lens, so i don't think it is the sensor that needs cleaning, its only my images that i have taken through the scope. So what would be the best way to clean it without damaging the optics. I can see some blobs of dirt if you like, when i look directly at the glass, but it is not dust. Any help would be great thanks Link to comment Share on other sites More sharing options...
Doc Posted March 10, 2016 Share Posted March 10, 2016 I always use Baader wonder fluid to clean my refractor lens and eyepieces. I consider it the best around. Link to comment Share on other sites More sharing options...
Guest Si2504 Posted March 11, 2016 Share Posted March 11, 2016 On 10/03/2016 at 19:38, Doc said: I always use Baader wonder fluid to clean my refractor lens and eyepieces. I consider it the best around. Ok thanks. I will take a look Link to comment Share on other sites More sharing options...
philjay Posted March 12, 2016 Share Posted March 12, 2016 From years of experience with refractors and imaging, muck on the objective will not be seen on your image. You will have to have a lot of muck on there to affect the image and then it will be just a general loss of light or a blurr. Before you clean any lens check everything in your imaging train. Sensor, filters, barlow. Muck close to the sensor will show as artefacts not on the objective Link to comment Share on other sites More sharing options...
Guest Si2504 Posted March 12, 2016 Share Posted March 12, 2016 1 hour ago, philjay said: From years of experience with refractors and imaging, muck on the objective will not be seen on your image. You will have to have a lot of muck on there to affect the image and then it will be just a general loss of light or a blurr. Before you clean any lens check everything in your imaging train. Sensor, filters, barlow. Muck close to the sensor will show as artefacts not on the objective These 2 example images was taken with the camera attached directly to the focuser draw tube, without any filters, barlows etc. But as you can see, in each of the images there are two identical black blobs in the image. What do you think they could be through your experience? Thanks Link to comment Share on other sites More sharing options...
Smithysteve Posted March 12, 2016 Share Posted March 12, 2016 I can't see black blobs for black blobs! Can you be more specific and show where the black blobs you are referring to are? ? Cheers! Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted March 12, 2016 Share Posted March 12, 2016 Hi Si (?). I assumed when I saw your 1st M31 image that they were dust bunnies... on your Sensor. If they are they will always appear in the same position on the frame every shot. I don't see them on my camera on day time shots when there is a lot more light. Did you flip your M31 image left to right? Link to comment Share on other sites More sharing options...
Doc Posted March 12, 2016 Share Posted March 12, 2016 I think the M31 black spot is a dust bunnie as well. I'm not an imager but have seen similar looking marks on photo's before. Link to comment Share on other sites More sharing options...
Werisit Posted March 12, 2016 Share Posted March 12, 2016 Hi Simon. I agree with Philjay. I think that for the blobs to be as sharp as they are they must be on the sensor (or rather the sensor filter). The M31 shot is reversed L to R so I'm assuming that it is the same blob in both pics. It's not unknown for dust to move about on the sensor as well. To test I suggest you take a pic, with a lens, of a plain pale surface, with the lens stopped down to f16. The small aperture will accentuate any dust on the sensor's filter as the shadow is sharper. Link to comment Share on other sites More sharing options...
Guest Si2504 Posted March 12, 2016 Share Posted March 12, 2016 Yes, the camera was in a different position on the scope when the pictures of m31 and m42 was taken, and i will try the test with a lens stopped down to f16. But whilst i do that and inspect the images, i will leave you with these pictures that was taken a couple of nights ago with just a lens attached. Thanks Link to comment Share on other sites More sharing options...
Guest Si2504 Posted March 12, 2016 Share Posted March 12, 2016 Thankyou to everybody that replied to help me, and a massive thanks to werisit. Did the test on a piece of white paper and for sure the little spec was there. A very gentle pass over the sensor with a cotton wool bud, a blow out with the air bulb and lo and behold, blob gone! Thanks again Link to comment Share on other sites More sharing options...
philjay Posted March 12, 2016 Share Posted March 12, 2016 10 hours ago, Si2504 said: These 2 example images was taken with the camera attached directly to the focuser draw tube, without any filters, barlows etc. But as you can see, in each of the images there are two identical black blobs in the image. What do you think they could be through your experience? Thanks Those are specs of dust in your imaging train, dust bunnies, so if you don't have filters, barlows, reducers fitted etc then its on your sensor. It may look clean but you have small specs on it. Muck on your lens would not be so small and concentrated. If you cant get rid of the dust then take some light frames and calibrate to get rid of them Link to comment Share on other sites More sharing options...
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