IR pics - GC2 hit

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • FaultyClubs
    Super Member
    • Nov 2014
    • 635

    #1

    IR pics - GC2 hit

    Saw a surplus webcam at Princess Auto for $2.99. Being a big spender I bought it, removed the IR filter from the sensor and turned it into an IR camera. On a recent slow day I decided to play around with some pictures of hitting on the GC2. Decided to post since others might find it interesting.

    This picture is with the ball sitting on the tee, ready to hit. Normal room lighting, looks black because very little IR light in the room. Also the GC2 LEDs and flash is so strong I have to turn the gain down to 5% otherwise the ball just blows out the picture.

    Click image for larger version

Name:	IR_on_tee_post.jpg
Views:	819
Size:	7.0 KB
ID:	70260




    The picture below is hitting with a mid iron. Some interesting things pop out here:

    1) The sequence of balls shows the number of images the GC2 takes for each shot. Roughly 10 images per shot. The last few are darker and may not always be used.

    2) The gap from the tee to the first image is the time it take the GC2 to realize the ball has been hit and start taking pictures.

    3) The flash is extremely bright. The sensor in this cheap camera is totally overloaded from the flash.

    4) Even though the ball is overexposed the logo on the ball still shows up well. Shows why having the logo facing camera can help with spin calculations since it is still visible when any ball dimples or imperfections could be washed out.

    5) My pants in this photo are BLACK. Yet to IR they appear white. This shows how choice of pants can affect the unit's ability to read the shot. 2 or 3 of the images are completely washed out as the ball passes in front of my pant leg. This kind of background may make it hard for the unit to find the ball. The GC2 is fairly robust since it takes so many pictures but on a Skytrak which only takes a couple pictures this could result in misreads.

    6) The club is visible even with no markings, with some reflecting tape it should be very visible. So maybe usable to observe the angle of attack! And maybe face angle if I aim the camera down from the top with a couple tracking dots.

    7) The foreground is part of the hitting mat. The green mat and white ball look completely different to us but in reality the green mat has high IR reflectivity so appears white to the camera. In fact it produces a very strong reflection which could easily overload the unit. Maybe some mats are better than others in this regard, I don't know. Also it shows how having the unit below the mat height could really make it hard to see the ball given mats have such a strong IR reflection.


    Click image for larger version

Name:	IR_hit_blackpants3_logovisible_post.jpg
Views:	736
Size:	88.1 KB
ID:	70261



    Just for fun I included this shot of a mishit. My 3 wood went under the ball and it rocketed off the top of the club face. Ooops. But again it shows how the ball gets lost in the pant leg reflection. Not good if the unit only took a couple pictures. Luckily the GC2 takes a several (in this case more than 10).
    Click image for larger version

Name:	IR_gain0_blackpants_3wood_mishit_post.jpg
Views:	724
Size:	122.3 KB
ID:	70262


    For this picture I rolled up my black pants which is much better as the bare leg has much lower IR reflection. However my black socks are still an issue...the first ball image is lost in the sock reflection.
    Click image for larger version

Name:	IR_hit_barelegblacksocks_3wood_post.jpg
Views:	713
Size:	67.9 KB
ID:	70263


    Finally, this image is simply to highlight that what we see and what an IR sensor sees can be completely different. This matters when we are trying to minimize IR reflections and interference.
    Both tape on the club face are black to the naked eye. Yet the black hockey tape on the right appears white to the IR sensor while the black electricians tape on the left remains black.
    I took this years ago when setting up my Optishot...people often tape their clubs with varying results and this might be why...they used "black" tape to cover the bottom of the club thinking it would make their white tape strip standout but in fact they may have used the wrong tape and just make the club bottom all white!!

    Click image for larger version

Name:	IR-BlackHockeyTape_vrs_BlackElectriciansTape.jpg
Views:	729
Size:	229.8 KB
ID:	70264



    Anyway, for whatever it's worth, just thought these test pictures might be interesting to some. The powerful flash, high speed camera and multiple images that the GC2 takes shows why it is so robust. It would be interesting to see how the Skytrak compares. I understand it only takes a couple pictures and I suspect the flash is not nearly as strong. But I don't really know since I don't have one.
  • driverdivots
    Senior Member
    • Jan 2015
    • 160

    #2
    Pretty interesting read! Very cool to see the actual shots from the gc2

    Comment

    • Ironstrokes
      Extreme Member
      • May 2015
      • 1012

      #3
      This is super interesting! Was hoping to see something like this out there but couldn't find it anywhere I looked on the internet. Great explanations on how the different tapes, pants, etc. are effecting the image. This is really cool to see. Now apparently the best thing is for us to play either buck naked with no sock even or to wrap up our lower legs with some electrical tape hahaha. In all seriousness though, wonder what type of pants don't have that much of an IR refection. If you come by anymore interesting findings definitely post them, really awesome stuff!

      Comment

      • FaultyClubs
        Super Member
        • Nov 2014
        • 635

        #4
        The flash was saturating my poor little sensor. I didn't have any neutral density filters so used a pair of sunglasses for better exposure. I also added a little sticky to the toe of the club to see the angle of attack better. Here's the result.

        It's about the best one can do with a $2.99 camera (the sensor being even less assuming they made a profit!) LOL

        I've always wondered why they use a point source for the flash. Any photographer knows that will cause problems with specular highlights, glinting and light fall off away from the boresight. All problems visible in this picture. If they fired the flash through a diffuser the picture would be a lot better for image processing.

        Click image for larger version

Name:	ir_hit_withsunglasses_1.jpg
Views:	730
Size:	223.0 KB
ID:	70328



        Also I forget to mention in the previous post. In my test the GC2 flash is strobing the image in a single frame so the background looks artificially bright. With a single image per flash the way the GC2 sees it the bright areas (pant legs, bright parts of mat etc) would be similar brightness as the golf ball.

        Oh well, enough playing around. I'm not sure i accomplished anything but it is fun to try something different occasionally.
        Last edited by FaultyClubs; 05-18-2016, 03:03 AM.

        Comment

        • Godfather
          Super Member
          • Dec 2015
          • 516

          #5
          It's super cool stuff!

          Comment

          • Ironstrokes
            Extreme Member
            • May 2015
            • 1012

            #6
            Originally posted by FaultyClubs View Post
            The flash was saturating my poor little sensor. I didn't have any neutral density filters so used a pair of sunglasses for better exposure. I also added a little sticky to the toe of the club to see the angle of attack better. Here's the result.

            It's about the best one can do with a $2.99 camera (the sensor being even less assuming they made a profit!) LOL

            I've always wondered why they use a point source for the flash. Any photographer knows that will cause problems with specular highlights, glinting and light fall off away from the boresight. All problems visible in this picture. If they fired the flash through a diffuser the picture would be a lot better for image processing.

            [ATTACH=CONFIG]n70328[/ATTACH]



            Also I forget to mention in the previous post. In my test the GC2 flash is strobing the image in a single frame so the background looks artificially bright. With a single image per flash the way the GC2 sees it the bright areas (pant legs, bright parts of mat etc) would be similar brightness as the golf ball.

            Oh well, enough playing around. I'm not sure i accomplished anything but it is fun to try something different occasionally.
            Feel like this image you are producing here would be great for determining changes in angle of attack as you said. That's really useful info especially when you ate trying to pump out a few more yards on the drives. Wish I could get the same type of image doing this with my skytrak but with it not having the 10 flashes like the gc2 I'm guessing it's not possible

            Comment

            • FaultyClubs
              Super Member
              • Nov 2014
              • 635

              #7
              Originally posted by FaultyClubs View Post
              I've always wondered why they use a point source for the flash. Any photographer knows that will cause problems with specular highlights, glinting and light fall off away from the boresight. All problems visible in this picture. If they fired the flash through a diffuser the picture would be a lot better for image processing.
              So I tried a diffusor. Happened to have a 4L ice-cream bucket holding my golf balls that looked about the right opacity so dumped them out and used that. Put the bucket over the GC2 flash and got the following:

              Click image for larger version

Name:	IR_hit_IcecreambucketDiffuser_1.jpg
Views:	726
Size:	152.3 KB
ID:	70459

              Compare this with the previous image. Without the harsh lighting and specular highlights this image is significantly easier to image process. Diffusors help a lot.

              The raw image actually has enough information to calculate all the ball launch parameters (although the HLA wouldn't be super accurate). Not bad for a $1 sensor made with yesterday's technology and covered by a cheap piece of plastic for a lens. If one were willing to spend $50 on a bigger, better sensor and a piece of glass for a lens they could probably make something ten times better. Add a speed trap to trigger the strobe and set its frequency and you'd have a launch monitor for less than $100! LOL

              Notice different socks with less reflection, same pants though.

              And just for fun I created an embossed version (a little edge detection, some noise reduction and embossing). The dimples on the golf ball are starting to appear!
              Click image for larger version

Name:	IR_hit_IcecreambucketDiffuser_1_embossed.jpg
Views:	699
Size:	281.0 KB
ID:	70460

              Comment

              • Ironstrokes
                Extreme Member
                • May 2015
                • 1012

                #8
                Thats insane! Super cool seeing that, wish I knew the first thing on how to do all of that, would love to see those images of my driver swing. That is crazy you did all this for under 5 bucks too hahaha. Wonder how it would show up on the skytrak, im gonna have to try this...may have to watch a youtube video or two on how to remove the ir filter though haha

                Comment

                Working...