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Speedbooster GH2 with CC30M sensor mod - Fishing Trip
  • Family fishing trip I shot a few days ago. It was totally improvised. I didn't know the location or what I'd be able to capture until we arrived. Shoots like this are fun - you have to think quickly about how to develop the story with what you're given. I wanted to share this with you guys as it was my first shoot that I can post where I used the c/y speedbooster. Great piece of gear. I've shot a couple commercials this summer with it as well - but they are not public yet. I used a c/y to m42 adapter which worked flawlessly with my 35mm f2, 50mm macro f4, and 135mm f2.5 lenses. Shot using smooth all -2, and on a monopod 561hdv, and a mini hi hat with a manfrotto ball head. Edited and graded in fcpx. I'm also using a Lee CC30M gel cut and fixed in front of the sensor to give me a more even color distribution of RGB. (You must manually white balance when doing this, but I always do anyways.) Utilizing a CC30M gel is an effective form of pre grading your footage before it hits the sensor. I've tested this out all summer and credit Aki Hartikainen whose initial tests with the gh1 sparked my curiosity for experimenting with getting rid of the gh2 green cast and better post grading using this method.

  • 27 Replies sorted by
  • Great variety of shots! What's that polygonal reflection in some of the shots?

  • Nice. Can you post some pics or vid of the gel mod of the sensor? How does it clear the shutter? Never thought of trying to mod the sensor itself.

    Whenever I shot with a filter I didn't white balance in cam, I just let it go purple then raised the green in post and it gave me a real nice image, especially of foliage. Your vid looks great.

  • @oscillian the polygonal reflection is the aperture blade flare from the 35mm tak. : ) @CRFilms - I don't have any pics of the mod. I will try and take one. I don't use the camera for photos so I've never actually thought to activate the shutter. I literally cut the gel square slightly larger than the sensor and then tacked it down in front of it. Held by adhesive tape. I figure I lose about half a stop, but with speedbooster I get it all back and more.

  • here's a post from Aki's blog about my journey into sensor modding using varying degrees of minus green gels. http://www.fourseasonshd.com/cgi-bin/csvsearch.pl?db=db1&tp=tp19&search=blueLight013

  • Great stuff. It is not easy to shoot things on-the-fly. Colors seem less muddy than usual GH2 footage, I'd say more Canon-like, which doesn't hurt sometimes. I saw such rich colors in other videos from yours on Vimeo. Did you use the CC30 with them as well, or is it just a matter of lenses and post color correction?

  • @pchristoph Nice video. Sensor mod seems interesting. Thanks for posting.

  • Try taking off the gel, and balancing the green/magenta in the custom settings, then shoot the same scene twice, once with the gel and once without. You may get a little more resolution. Just a suggestion. Make sure you use a setting that does not add a cast to the highlights, for example, avoid cinema. You can't really correct for cinema, it is more like a filter. If you find the gel is better, post two clips side by side, and make sure that they are unlabeled, and then we can learn from the results.

  • @DrDave from what I read this technique involves "tricking" the way the sensor works and pushing more information into red and blue channels (which otherwise deliver less info than the green channel, in 4:2:0). So I guess it works if it is done "before" the sensor and not "on/by" the sensor. But I could be completely wrong ...

  • @flabo yes, I've used the sensor mod in videos I've made the past couple of months. You are right about 'tricking' the sensor as a way to sort of pre-grade footage. Color correction in post for this post was quite minimal : exposure, saturation. @DrDave my camera settings are smooth -2 and white balance manually. Not sure i understand what you mean by resolution but grab a lee or rosco color swatch and try this for yourself - you'll enjoy the benefits. I just don't have time to do comparisons right now. For me, colors are slightly richer and better able to handle grading with this sensor mod as well as eliminating the green cast. Skin tones look great out of the box! @matt_gh2 you should try it :)

  • @pchristoph I tried it and it was better with the in cam processing.

    By resolution I mean the amount of detail that is cleanly resolved.

    Looking at your video on my calibrated monitor, it appears to me that the grey point is not set correctly and the colors as a result look a bit underexposed, along with a slightly washed out look. Of course you could be going for that look, as a sort of nostalgia filter but I think the grey point could still be lower. I particularly notice it in the skin tones as well as for example the blue squares in the shirt. The green in the trues is washed out as well, not so much the foreground which has a fall color but the evergreen background color.

    I think your color would come out truer with the green/magenta shifted in cam, and then grading it however you like in post. But I can understand that you don't want to post a comparison, it is just helpful for us to learn from.

    @Flabo, maybe it works, would be interesting to see a carefully done side by side comparison.

  • @DrDave I don't have a calibrated monitor so I'm grateful for your ability to see things I can't. I'm using only an iMac for grading so far. I know a better monitor would help me here! For this video I color corrected for a slightly lifted low saturation feel to help with the midday, high contrast shoot time.High contrast is not a friend to the gh2. When you say green/magenta shift you are referring to clicking the color two towards amber and one down magenta? If so, it's a technique I'm familiar with. I'm glad you tried the gel over the sensor too. For me, I really like what this is doing to the image. A benefit to this method of using the minus green gel mod at the sensor is that it affords me the ability to create a stronger 'look' with color adjustments instead of using them to take out the green shift. The journey continues in how I can get the most from this story making machine.

  • I'm curious about this. It seems to me that whether in-camera processing would offer better or worse results depends on when that processing takes place. My guess is that it's difficult to do a 1:1 comparison but in-camera processing should be better as it doesn't put anything in the optical pathway to reduce light or sharpness.

  • That gel seems to take some of the digital edge off too - looks fantastic! Great work.

  • @DrDave dumb question: how do you actually balance green/magenta in cam? I don't have my GH2 at the moment, trying to do it on the GH3 but the only thing I can do is to adjust the WB through the manual hue selector, which I don't think is the correct way (I should minus green and then adjust the WB to compensate it, right?) EDIT: ok, I guess you mean the technique described by eoshd, which corrects into the WB @shian yes thanks, got it!

    @pcristoph did you used the gel in the distillery video as well? It looks great and different from anything I've seen on the GH2

  • there's a custom grid you can adjust on the GH2 which I've done to shift the color spectrum any way you like. Just hit the WB button, and then hit the down arrow. Adjust to your heart's delight.

  • @shian thanks for checking it out. I love the side benefit that the gel takes the digital edge off as well. And thank you for teaching us from your wealth of pro experience. I've benefitted from your 'exposé in the zone' tutorial and its made me work smarter at becoming a better shooter. @flablo the distillery 'tank' video released a couple weeks ago has the gel mod applied, but the distillery story released last Spring doesn't. Glad you like the coloring on it - it was an artistic choice and I'm pretty happy with how it turned out.

  • @pchristoph Many Macs have a gamma shift, so if that's the case you have to correct for that. Later versions of the OS have a utility, and you can make some basic choices, but you have to correct for ambient light, and for that you need a colorimeter. You can get a decent one for $75-$100. You obviously have some great skills, so good luck going forward.

  • If your iMac (like mine) has been properly calibrated, then what you see is what you get. I decided to activate my vimeo account on my bluray player a few nights ago just to see how my stuff looks to the public coming off the set top box. It looks even better on my TV than on my iMac. BUT no surprises. No colors in the wrong place, everything looks exactly the way I intended it.

    IMO Apple Cinema displays are perfect. So check the scopes, if the scopes don't show the grey point too low, and you don't see it on your Apple display, then it ain't really there. You might have underexposed a bit here and there, but the skin tone looks fine to me. BUT I like to underexpose skin tone, I like the way it looks. I think what dave is seeing is a result of the grade, which does not have true colors, but a dirty almost gray/brown toner type look to it. Something I use all the time.

  • @DrDave thanks for the encouragement, I appreciate your eye for detail and I will check out a colorimeter. @shian the grey point looks good to me, it is a bit low. I do like what I'm seeing watching work on my Panasonic tv as well. Colors look as I intended. Thanks for the input guys, I really appreciate the good guidance and support here.

  • @shian the monitor calibration is heavily dependent on ambient light, so I still recommend a colorimeter with an ambient light sensor, for both color and contrast.

  • solid advice - but if you aren't grading in a darkened room, then Joe Pesci have mercy on your soul... :)

  • @shian, I'm curious, in your experience do the WB presets drift over time on the GH2 (or cameras in general) or with the warmth of the camera perhaps? I'm not a fan of doing scene-based custom WB but I'm curious about adapting this filter to a naturalistic style of mixed color temperatures, creating, essentially, a revised or offset preset for tungsten.

    I think I'm going to give this technique a go the next time I'm shooting daylight, regardless. Really good looking stuff @pchristoph

  • That I cannot answer. I have no idea. I'm always adjusting WB for whatever I need, so it's never been an issue for me.

  • @shian--I actually don't grade in darkened room because the effect of the backlight in a darkened room becomes the light source, and the grey point can then change with the size of the monitor. I do one pass on the calibrated monitor, then another round on the calibrated TV, then one pass each on Rec 709 and full 0-255, since the output is not only for internet but also Blu-Ray.

    I have to assume that the end user will be viewing with some ambient light, and this of course is a crapshoot, but the last pass gets compared on Blu-Ray to reference samples of current movies, since if a TV is adjusted by the end user, that's where they will tweak the settings. The computer output is just a guess, but the high demographic target is the iPad user, so I use that as a reference. You could use an iMac as well. No easy answers here. I expect in a few years I will use a phone as the reference for YouTube.

    Of course there is always the possibility that I am doing it wrong, there really is no way to know. I don't know anyone with a properly calibrated TV.

  • @pchristoph, thanks for sharing. Love the look and the feel. Like shian said, the digital edge out. Will definitely try it out.