Anyone using an EOS 60Da?

Discussion in 'Image Capture' started by Maneesh Yadav, Sep 7, 2018.

  1. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    I'm in the process of setting up my Canon EOS 60Da for imaging with hyperstar on a C14 Edge HD (feathertouch/microtouch focuser). I'm running into some basic problems initial focusing on a focus star. The star seems really big according to MaximDL autofocus (or FocusMax) and I don't trust I understand what is going on.

    I'm decided to test EOS 60Da on my AP 6-inch (FLI DF2 focuser) where things were working great with the SBIG 402 ME. The purpose was to control for any possible problem in the optical train of the C14, since I haven't used that scope for imaging yet and the feather/micro touch was just installed. The stars on the EOS 60Da seem to be big according the the HFD measurements I see in MaximDL and FocusMax (HFD is always >12).

    I can't remember what star I was on in the attached screenshot but I did try a a variety of magnitudes between 1 and 6 without any apparent change in the HFD.

    If there is an issue, it seems to be in the camera. Is this normal for DSLRs or this camera? Is there a stale setting that could be affecting the imaging or the calculation? Can anyone else confirm that they are using an EOS 60Da in this way and don't see this sort of behavior?

    May be doing something very foolish here, but I can't figure it out.
     

    Attached Files:

  2. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    2,498
    Your focus star is too bright I think. Keep in mind the pixels on the 60Da are 4.3um in a 5184 x 3456 bayer array (RGGB), so you might want to bin 2x2 to get started.
    By comparison, the ST402 has 9um pixels 765x510 all mono.
    So the 60Da pixels are 1/4 the size. Binning them 2x2 might give you more like the result you are expecting.

    Looking at the V-curve, am betting it will pop into focus somewhere in the 900's of position am guessing.
    So refine that V-curve (eg start the focus range around 750 to 1100, and finer steps. Then use a smaller step size.) It will take a while.
    The hyperstar is going to be challenging as the scope is so fast in that arrangement (f/2 ish?)
     
  3. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    Thanks for the advice Colin. I didn't record the images systematically as I should have (I tried FocusMax too and with 2x2 binning), but using a dimmer (5.something) star didn't seem to help.

    I'll try again and see if I missed something.Yes I am pretty certain that the camera is in focus somewhere around the minimum in the V-curve, so that makes sense. The stars seem worse on the back of the C14.

    I notice with he 60Da the background noise seems to be higher, don't see the same contrast between the star and background for reasonably long exposures.

    Ah:
    https://diffractionlimited.com/help/maximdl/DSLR_Focusing_Tutorial.htm

    Maybe this was the issue:

    "DSLR cameras always have several Readout Mode options. Although it is the best option during imaging, do not use the Raw Monochrome option for focusing, because the color Bayer matrix will make it impossible make proper measurements on the star. You can use the Raw Color mode; however, for most cameras the image download time is slow enough to be very inconvenient for focusing. The best option is usually to use the JPEG Monochrome mode. The image downloaded is noisier, lower bit depth, and has compression artifacts; however, the image degradation is not bad enough to significantly affect focus measurements."
     
  4. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    2,498
    Background noise will be much higher on the 60Da - the chip isn't cooled, and that model is noisier (I own own).
     
  5. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    Yes indeed. Mentioned it to see if visible bg was apparent in other people's systems when focusing on stars (in case that had something to do with the weird HFDs). I have a good feeling changing the camera readout mode will fix things since I know the whole system otherwise is working fine.
     
  6. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    I'm still having problems getting a food focus curve in MaximDL and FocusMax even after testing with "JPG Monochrome" mode.
    I've seen that the min HFD can change a lot (12 previously, in my last run not much below 40), I think the key factor is the exposure time; next run I'll try and make sure that I select the right magnitude for an appropriate flux for a 0.1s exposure. My guess is that the higher background on the DSLR inflates the HFDs so I need to get the right magnitude in as short exposure as I can. Am I the only one having trouble focusing with the EOS 60D?

    Colin, do you use autofocus with your EOS 60Da? What sort of HFDs do you see?
     
  7. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    2,498
    Maneesh, I havent used that camera in months, so can't give you any useful info.
     
    Maneesh Yadav likes this.
  8. SkyHawk

    SkyHawk Cyanogen Customer

    Joined:
    Apr 11, 2016
    Messages:
    249
    Location:
    Iowa
    Hi Maneesh,
    I use Canon 60Da on occasion with LX200 ACF 12 inch and AT65EDQ scopes. I use focusMax for focusing with a Optic TCF-S focuser. I don't recall what the minimum HFD is but I use around a mag 7 star to focus on with the LX200.

    Canon Setup:
    High ISO noise reduction=Disabled
    Long exposure noise reduction=Off
    Auto Power off=Disabled
    Sensor Cleaning>Auto Clean=Disabled
    ISO=800
    Quality=Raw

    Maxim setup:
    Camera Model=Canon Eos II
    Mirror Settle Time=1 second
    Binning=1
    Readout Mode=RAW Monochrome

    When running V-curves I use a step size of what ever the Critical Focus Zone calculations are for the scope. For the LX200 I use 100 steps for the optic focuser.

    Keep the Center value in the the VCurve Sequence at the focus point. This will shift during the Vcurve measurements and cause the absolute value of the left and right slopes to increase. Depending on which side of focus the center position is on will cause either the right slope or left slope to be higher value.

    It's important to have to near focus position in the linear portion of the slope. Too low of a near focus value can throw the focus off.

    Bill
     
  9. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    Thanks for the detailed information Bill. It is interesting that you are focusing with "RAW Monochrome". I noticed that "JPG Monochrome" would occasionally seem to get stuck (I seemed to keep reading an old frame).

    I'm going to move forward and put the hyperstar on the C14 with the EOS 60d, even though don't seem to have yet validated it is working on the back of my AP-6inch. It sure seems to be a camera setting somewhere or the choice of star, lets see if I can find it.

    If you do happen to find your HFDs/fluxes/exposure times (for focusing) anywhere, please do post as it may help me find my problem.
     
  10. SkyHawk

    SkyHawk Cyanogen Customer

    Joined:
    Apr 11, 2016
    Messages:
    249
    Location:
    Iowa
    Hi Maneesh,
    It maybe some time before I use the 60Da. I found a focusmax run I did in July which I am attaching. This is with a LX200ACF 12inch and an optic 6.2 focal reducer.

    Hope it helps,
    Bill
     

    Attached Files:

  11. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    I've got the EOS 60Da working now on the C14 + Hyperstar. It's really nice seeing the images come in so quickly. I was capturing in RAW Color readout mode when I realized that I should be capturing in RAW Monochrome mode and doing my calibration on those files. MaximDL seems to automatically get the contrast much better on the RAW Color files, they never look that good in PI.

    One thing I am noticing is that Bias and 30s Dark frames have what appear to be essentially the exact same level. It feels like there is some sort of automatic dark subtraction going on the camera. The EOS 60Da can do an automatic dark exposure of the same length as the previous exposure but I have that turned off (C.Fn II -1 Long exposure noise reduction). Has anyone taking bias and dark frames with their EOS 60Da or might know what I might be doing wrong?
     
  12. Brian Atteridge

    Brian Atteridge Cyanogen Customer

    Joined:
    Jan 23, 2017
    Messages:
    32
    Location:
    Lewisville, TX
    I have an astro modified 60D which is the same camera as the 60Da but i modified it for astrophotos myself. There is also a High ISO noise option on that same menu section, make sure this is also off too or it will act a lot like the long exposure noise reduction at higher ISO settings and could be the cause of that. I have both off and my bias frames and 30s frames do look different.
     
  13. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68
    Ah , just to follow up it took me a bit to work through this and had to look at a few sources. If anyone else is interested you can follow through here:
    https://www.cloudynights.com/topic/664353-eos-60da-dark-and-bias-frames/

    Long story short: There is some rather opaque dark frame correction/dark current "suppression" going on; this leaves a nagging hole in one's understanding of just what is happening how to deal with it. Some commenters are confident regarding the mechanism, and it obviously isn't anything magic, but without a really clear description from the manufacturer it is hard to be confident it is being corrected in the right way.

    I could see consistent dark noise patterns (a horizontal dark line) consistently in my images so did apply dark subtraction in the normal way and it seems to produce acceptable results. Hope this helps anyone else who gets here.
     
  14. Brian Atteridge

    Brian Atteridge Cyanogen Customer

    Joined:
    Jan 23, 2017
    Messages:
    32
    Location:
    Lewisville, TX
    I decided to try a few tests with the camera only and no software. With long exposure noise reduction, high iso noise reduction, and auto lighting optimizer turned off i was able to take a test 30sec image and using the camera can see noise when i zoom in. With the long exposure noise reduction it disappears. Also Only with the long exposure noise reduction turned on does it take an equally long exposure with the shutter close otherwise it takes about than 5 seconds to write the data to the card.

    Now this was with JUST the camera and nothing else so if the camera were going to still be doing noise reduction you would think i would see it in the camera as well as on the pc. If it is doing any reduction still it would have to be a software interpolation and that would still eat up more than 5 seconds. I feel that whatever is happening on your camera may be something else causing what you are seeing and not something the camera is doing in the background.
     
  15. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

    Joined:
    Jul 12, 2016
    Messages:
    68

Share This Page