Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Adam J

Members
 View Profile  See their activity

  • Posts

    4,950

  • Joined

  • Last visited

  • Days Won

    1

 Content Type 

Everything posted by Adam J

  1. Adam J
    Yes you can use a free program called iris to manipulate the raw files and save them as FITS prior to stacking.
  2. Adam J
    Looking good, but i think that there is much much more to be teased out of that data, it could probably stand another couple of stretches on curves as a minimum? Your background is very black, if you look at some other pictures of M42 the entire area is full of dust and hydrogen. Assuming that this is a DSLR then did you remove the blue and green channels prior to stacking? When you use a h-a filter on a OSC camera only the red channel has data the other two only introduce noise to the image.
  3. Adam J
    In my opinion you get better results with a DSLR with the 130PDS just because of the faster optics.
  4. Adam J
    If this is your first ever image that is really very very good going.
  5. Adam J
    Looks really nice, but perhaps a touch purple? I think that means you need to add a tiny little bit of green to the balance...or is it reduce blue.
  6. Adam J
    This is a reprocess of my first ever Narrow Band image, a bi color or the eastern veil taken with a cooled Canon 1000D. 8 x 20 min Ha ISO 800 8 x 20 min OIII ISO 800 Its very highly cropped for various reasons so not too great if you zoom in. Its no CCD image but I was quite pleased with it at the time and I think that I got more out of it now that my processing skills have improved.
  7. Adam J
    And now with some OIII 8 x 900s ISO 1600 OIII - Blue 16 x 600s ISO 800 Ha - Red Did not bother with any calibration frames. Posted in imaging section too but I like to share with my fellow 130PDS users
  8. Adam J
    Here is 18x600s subs with my cooled 550D and Baader 7nm Ha filter. I really am looking for some advice on this as I am unsure if I have over processed it. I dont know if I should add more Ha or get the OIII next...The Ha is the most important layer as ill re-use it for luminescence later. problem is that I dont think that I have resolved much detail here as the seeing was not great when I collected this data. I posted this in the processing section of the imaging forum also but did not get much of a response so thought I would try my fellow 130PDS users. I have a couple of versions processed using different techniques, thoughts?
  9. Adam J
    Its difficult to say....they are separated by a number of sensor generations. My experience of the 1000D was that it ended up only just slightly better following mono conversion.....my point being that if you do try and its successful then you may as well have something worth while for you efforts. On ebay you can often get cameras that are 'broken' in such a way as to not have any effect on their performance for astronomy..auto-focus for example or scratched view finder. So if your patient then you might be able to get something more up to date but still at a rock bottom price.
  10. Adam J
    It was has been my first scope and I have not regretted it for a second. To my eye the whole colimation thing is a fuss about nothing, if you are at all technically minded as most of us tend to be it wont be an issue for you at all. It comes well below polar alignment and image processing in terms of difficulty in my opinion.
  11. Adam J
    Weird thing is that very few people have done proper side by side comparisons.
  12. Adam J
    The problem is applying a very very even coating. If you get a variable thickness you will have all sorts of distortions in the image and a horrible flat frame.
  13. Adam J
    The picture I posted of the mono 1000D m45 is just a bare sensor. The first optical element that light reflected from the sensor encounters is my CLS clip filter followed by the Baader MPCCMKIII (which is fully multi-coated) then a threaded 2 inch UV/IR block filter (the CLS is not a CCD vershion). I would not say that I had any horrible reflections especially given how bright M45's stars are, reflections were comparable to RGB camera for an identical exposure. I think reflections are actually more likely to be an issue if you place an optical element very close to the sensor.....I just left the sensor bear with the wires protected by a plastic shim within the old filter mount. Others may had a different opinion but I would leave the sensor 'naked' as the process creates allot of debris and to be honest its useful to be able to clean the sensor using mirror lock up / manual sensor cleaning. You will end up with left over debris around the margins of the sensor as you cant get too close to the gold wires when cleaning the sensor after the mod. If debris shifted on the sensor and you had a clear glass element in front of it then you will almost certainly end up having to full disassemble the camera to clean the sensor. The best thing to reduce relections from the sensor is to keep the nearest glass element well away from it. Also having poked, heated, scraped and mechanically polished the surface of the sensor....do you really think it needs a glass layer to protect it? A clip filter will do the job of keeping dust out just fine and will be significantly further away from the sensor. You can get clear MC glass clip filters for EOS APS-C from modern astronomy....not so sure about a full frame cameras though. Dont try to bond anything to the surface of the sensor!
  14. Adam J
    6D is an awesome sensor, but its also expensive. You will be a brave man to try that camera as your first mono mod. How much are the replacement sensors. I would be going for the ASI1600 at that price point myself. Also dont underestimate the effect of cooling....and that is much harder on most full frame cameras not least because of their weight.
  15. Adam J
    That would happen with tilt.
  16. Adam J
    Yes I agree, however...QE is a measure of the percentage of the incident photons converted into electrons and that includes the effective aperture of the pixel. So in terms of signal to noise per pixel although the Nikon cameras start out with a higher QE ~50% as opposed to Canon 40%. You have to also consider the smaller pixels in the newer cameras. I calculated it and the light collected per pixel in my 1000D at 35% QE is still more (per pixel) than the D5100 with its QE of 50%. However the D5100 has better noise so it gains quite a bit of performance from that. Incidentally in your link they compare the original 5D with the newer Sony sensor...not a fair comparison. The 5D had horrific QE (26%) and the 5D MK2 (31%) even in comparison to the 1000D (35%) so while the 1000D has poor QE its not so poor as the two sensors pictured in your link. I did think about the 550D (same sensor as 600D) with QE (41%). However my logic is that if the 1000D is breaking even using super pixel, (but worse when processed for full resolution) then the 550D might do a little better than breaking even and the D5100 might do better still....but even if the D5100 is seeing a performance advantage post mono mod due to its sensor construction I would not expect it to be a huge one, i.e. it might not be sufficient performance increase to make it worth the effort and the D5100 is more expensive. In terms of risk vs reward, independent of the camera / sensor a larger performance boost is obtained through cooling than via a mono mod in my experience. If you get a D5100 and have a go with it, please please post some analysis here. I would be very interested.
  17. Adam J
    I use the Baader MPCC MKIII, yes it does not change the focal length. When Skywatcher made my 130pds they set the mirror right to the very rear of its possible travel. I have never used the GSO one.
  18. Adam J
    Those look like a reflection, when you modified the 600D did you remove both of the filters or just the rear filter? You look to have a little purple haloing too. Custom white balance is what i do. I would be surprised if its coma or tilt though as your stars are still nicely round at the edges of the image.
  19. Adam J
    Yes that is a good method. You can do all of this during the day if you move the polar scope horizontal and point it at a distant object. Its easier than mucking about in the dark.
  20. Adam J
    Yes its tricky. If you place polaris onto the center cross and then rotate the RA axis until it moves to about the maximum distance from the center cross then adjust the reticle so that the star moves back 50% of the way towards the center cross. If you mean that the large circle around the center cross is not round then yes thats not normal. You may have taken the adjustment grub out too far and the reticle may have slipped.
  21. Adam J
    Do you know how to correctly adjust and calibrate the polar scope reticle?
  22. Adam J
    Ah still not got the guiding working then. Nice one removing the IR filter yourself its easy and too many people scared to do it.
  23. Adam J
    What exposures did you use? Is the camera modified?
  24. Adam J
    Cooled mono 1000D M45. All in all i think that the camera breaks out about even following the mod. Still it was an interesting project
  25. Adam J
    Finally fixed my extra diffraction spike issue! I have confirmed the cause as focuser tube ingress into the light path. So for future reference both this and twisted spider vanes can cause the problem. The fix was to move the primary up the tube hence moving the focus out. I got some more data on M45 in the process using my mono 1000D and combined it with my original RGB as a luminescence channel. Although I had a processing misshap with the stars on the right of the image.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.