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Darth Takahashi

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Posts posted by Darth Takahashi

  1. I have followed the link, its very interesting, however wouldn't it be good to place three images side by side...

    STD DSLR, MOD DSLR & RGB CCD

    Your image of IC434 & B33 is better than mine since it definitely has more contrast. The question for me is does it contain more detail and if so how much more? Finally, how does that compare against a comparable CCD (large sensor) camera?

    I have seen a lot of these modified camera's on the internet for sale and I just wonder whether or not its appeal will last?

  2. Thanks for the replies and adjustments to the image so far. For the record, I don't mind anyone adjusting the images that I post so long as you let me know what you did of course. Thats why I'm here - to share and learn too.

    I'm not convinced that more subs will help me? The reason is that I'm sure that I'm running in to the limitation of my unmodified camera. The 1DMIII makes an excellent jobs of the brighter M42 but it doesn't seem to be able to cut it with IC434 & B33. I'm never going to mod the 1DMIII but buying a second hand 400D isn't out of scope.

    The question that I'm asking myself now is what would a modified camera bring to the table, just how much more detail could I expect to see? Especially with these predominately H alpha regions?

    Is anyone using a modified Canon and what would be your advise?

    Neil.

  3. I've struggled with this target for a long time now. It seem that a lot of things have conpired against me, including the weather. Anyway this is my best attempt so far at capturing the Flame and Horse Head Nebula.

    Telescope : TOA130F

    Camera : D1MIII

    Filter : Astronomik CLS

    Integration : 5x 20min subs

    11895_normal.jpeg

    (click to enlarge)

    I'm also sure that I'm running into my processing limitations...

    Most of this was processed using MaxIm DL5 (Calibration, Alignment & stacking) and then finished in PhotoShop (Curves & layers)

    I hope you like it, Neil

  4. If your going to be doing unguided exposures then for an 85mm lens and a target within the 30 - 60 degrees range 15 seconds will be your limit. A simple barn door tracker can be used to bring much longer exposures into range. Using a 300mm lens is definitely going to require tracking of some kind to be successful.

    A two arm barn door tracker is definitely the way to go with the 300mm lens.

    http://education.jlab.org/tracker/index.html

    Another PhotoShop trick is to use the FILTERS->NOISE->DUST / SCRATCHES option to remove the stars. For extended objects you may need to tidy up a bit with the clone stamp. I make all my flats this way.

    Last comment for now, all lens are equal at f8, therefore don't shoot wide open, the center will be OK but the corners will not impress! Stop down by at least 2 stops at first.

    Neil.

  5. I also have used a Canon 5D successfully for astrophotography, admittedly, with an APO which you still need to decide to purchase in the future. Regarding the camera and capture there are two mandatory points;

    1. Only use up to ISO800 with BULB. higher ISO are too noisy in the RED channel.

    2. Only shot in the RAW format, never shoot in the standard jpg format

    Regarding light pollution you can take some simple actions to try to beat it. First try to find a dark or shaded corner of your garden to shoot from. If there isn't any shade then try to introduce some with a simple cloth screen. Although this may sound stupid use a sun hood. This will prevent a lot of stray light from entering the lens and will narrow down the direction that the LP can enter from.

    Next take some test exposures of 15, 30, 45, 60 seconds and higher to find your local SKYGLOW limit. You should notice that the exposures will become increasingly more and more orange. Now the subjective point, pick the best exposure? Some orange SKYGLOW can be tolerated and even subtracted during your digital processing work flow.

    Use this exposure as your standard for all future imaging. A word of caution, the SKYGLOW limit will vary with your weather conditions and some days will be better than others. On thoughs day increase your exposure slowly.

    Finally, always shoot BIAS frames and DARK frames. DARKS most be shot with the same exposure as the LIGHTS or images only with the lens cap on. This records the thermal noise coming from the camera. BIAS frames are shot at the fastest exposure with the lens cap still on and these record the readout noise from the camera etc...

    Follow the normal image calibration or reduction procedures, there is a lot of information on the internet about this.

    And finally expect success, post your images here no matter how bad you may think they are. The people here can help you to analyse them and to improve them. I have substracted a lot of SKYGLOW using Photoshop and a difference layer after finding the offending orange colour using the eyedroper tool. Its not impossible, its just also not that easy, however, a lot of the techniques that you need will become second nature after a while.

    One book recommendation "Wide-Field Astrophotography by Robert Reeves" ISBN 0-943396-64-6. The book focuses on the use of film, however a lot of the information still applies to Digital.

    Good luck and I look forward to seeing some images.

    11813_normal.jpeg

    (click to enlarge)

    Here is an image of M13 taken with an unmodified Canon 5D, no filters just straight through an APO.

    Neil.

  6. Attached you can find an image of the moon where I have pushed the colour / saturation as much as possible. The image was taken straight through my TOA130F with no filters or reducers etc. Just the canon 1DMIII on the back. You can really see the green and blue areas of the moons basins coming through. Does anyone know what are the different types of rocks that make these colours?

    11724_normal.jpeg

    (click to enlarge)

    Weather permitting I'll try again soon with the M250 and reducer since I don't want too many images to merge.

    Neil.

  7. MartinB, I haven't needed to collimate the M250 yet. I brought it back from Japan myself and the star test went very well. The only real problem I can already see with collimation is that the weather here isn't really good enough to use a real star. I'm going to make an artificial star with some fibre optic cable, then the problem will be to get it in line of sight at some 60 meters distance!!! Anyway, the good news is that they hold collimation well. I have had a second hand M210 which I sold to fund the new M250. The reason is the the M250 focuses using the secondary, once focused it stay put which is great for imaging.

    Ron, Bert's own scope is a TAL200 which he has greatly improved, collimation and back focus. He already gets some great results with this scope so when I tolded him I was out with the M250 he came around to test it out! Actually, I wanted to borrow his IR pass filter etc... I'm going to try my web-cam when I can but its the colour version, no mods!

    Thanks for the comments, Neil.

  8. I have a standard Phillips SP900 web-cam but I wanted to see what I could do with the HX916. I thought the extra resolution might help. However, with subjects like the moon you right in that web-cams and Registax rule!

    You can find some web-cam images taken with my M250 at the following link;

    http://www.astroforum.nl/maanmozaik-ii-t16611.html

    My friend Bert came over with his modified Phillips 840k web-cam, it has a monochrome chip.

    The weather is changing this weekend and not for the better, never mind its seems that I'm just now getting your weather, thanks!!!

  9. No Billy that's great, how did you make the adjustment, with Photoshop?

    Does the CLS always bring a cyan cast to the images? I must admit that I didn't notice it in the image since its predominate blue, thanks for the help.

    Neil.

  10. That's a good point Richie, I forgot to add that I used an Astronomic CLS filter. This helps to control local light pollution. Without it my sky glow limit is about 5-7mins depending upon the conditions. With it I'm able to get up to 15 - 20min subs. That makes a big difference to the final image quality.

    I still hate doing darks, especially 15 / 20 min darks... but as we all know there mandatory!

    Neil.

  11. I think its a great image and would have love to have taken it myself... I don't think the scope is the problem, its more to do with the flattener which I've heard isn't that good from WO. On another forum people are using Televue flattener instead.

    If your striving for perfection, your not there yet but your closer to it than me!

  12. Here is an image from Christmas 2008! Sound so long ago now! The sky open for a few days after Christmas and I managed to gather 2 hours of data to capture the nebulosity. The image was taken with my TOA130F at 7.7 with a standard Canon 1DMIII.

    11647_normal.jpeg

    (click to enlarge)

    Hope you like it, Neil.

  13. No field flatterer was use, there is a little field curvature but overall it isn't so noticeable. I'm a lucky boy since I have two dream scopes. The TOA130F and the Mewlon M250, working in Japan helps since buying this equipment in Europe is defiantly out of the question.

    If you ever visit Japan and Akihabara (10 min from Tokyo), look up a shop called Starbase, its slice of Takahashi heaven at prices that you won't believe! :mrgreen:

  14. Attached is an image of the cater Copernicus, seeing was good but unfortunately the transparency was poor.

    The image was taken with Mewlon M250 and my HX916 Starlight Xpress ccd in infrared light using an infrared pass filter. Its very challenging using a 3000mm focal length scope under such conditions. Let's hope the weather improves!

    11636_normal.jpeg

    (click to enlarge)

    Hope you enjoy the image.

    Neil.

  15. I guess this is everyone's favorite target at this time of the year. Bright, easy to find and relatively easy to image.

    The following was taken with a TOA130F at F7.7 and with a standard Canon 1DMIII, no modifications etc...

    11634_normal.jpeg

    (click to enlarge)

    I hope you enjoy my latest attempt at imaging this famous nebula

    Neil.

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