PharmerPhil

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Posts posted by PharmerPhil

  1. Quote

    anything below 35mm is considered a "fish eye" lens.



    That isn't true. It is true that the wider a lens gets, the more it has to distort the image. A lens is effectively looking at a sphere (i.e., the world), and is projecting that image onto a flat surface (i.e., the imager or piece of film). The wider a lens is, the larger a portion of the sphere it sees, and the greater portion of the sphere it has to distort. How it distorts that spherical shape defines whether it is referred to as "fisheye" or "aspherical." It is easier to build a fisheye lens, but the better lenses use aspherical distortion to give a more natural appearing image. In an aspherical lens, the horizontal and vertical planes are preserved (hence no warping of the skyline). But is has to distort somewhere. Usually you can see this on the diagonals of the image if there is something there. If someone's head is in the corner it will appear on close observation that their head bulges towards the corner. But this is usually more natural looking than a curved skyline, or a curved wall that the viewer knows is actually straight.

    Of course it is harder to build a good asherical lens, and hence the astronomical cost and weight of lenses like the Canon or Nikon 14mm. On zoom lenses it can get complicated because the image shifts from wide to tele. And usually the distortion varies from being slightly fisheye to slightly pincushion (the opposite of fisheye, where straight horizontal or vertical line curve towards the outside corners). But better zoom lenses like the Canon 10-22mm give a reasonable balance without being considered fisheye.

  2. I jump the 15mm fisheye Canon for tandems. Although last weekend I borrowed a Tamron 10-24mm lens and loved it. I was jumping it @ 10mm for freefall, and would zoom in to 24mm for landing shots. Plus it isn't a fish-eye! Thinkin' I might have to get me one o' them. Besides, I need a super-wide zoom for non-skydiving stuff too (rationalizing,...).

    FWIW, I think the kit lens (18-55mm) is too narrow for my flying style, and can sometimes have a hard time focusing in less than ideal conditions. It sure is cheap and light though.

  3. If I were you, and I didn't know how to do this, I would find someone else with experience to do it for me. Seriously, if you've never done something like this before, it isn't wise to try it for the first time on your prized helmet without even a trial run on a scrap piece of something.

    However if it were I, I would remove the helmet liner, tape the area to be cut with blue painter's tape, draw a very accurate circle in exactly the right place (double checking both sides of the helmet for clearance, and the circle for accuracy), and use a hand-held air-grinder with a tapered carbide tip to cut the circle (I guess one could use a Dremel tool, but I like the speed and horsepower of an air grinder). On the first pass, cut at least an 1/8-inch smaller than your circle, and then do a second pass to bring it right to the line. You could alternatively use a high-quality saber-saw (I like Bosch) with a very fine blade, but I would still stay a little shy of the line and clean it up with a die-grinder or half-moon files.

    Either way, consider how you will hold your helmet still during this operation. I have done a lot of things like this, and I prefer to sit and hold the helmet between my knees, brace my elbows on my knees, and hold the grinder securely with both hands. Eye, and ear protection and a high-quality dust mask are recommended (a real cartridge mask, not a cheap, medical, ear loop face mask).

    Yes, most people recommend covering the exposed CF with nail polish on the theory that these tiny particles could get in to your electronics and wreak havoc. In practice though, I have never seen this actually happen. But better safe than sorry...

    Good luck!

  4. I have over 2500 jumps on Sabre2 150s and I love them (1.3:1 loading, just got my 3rd line set on one of mine). Good, soft openings, and I can get back from a long spot if need be (try that is you're videoing the last tandem out using a Spectre). I did demo Spectres, and while their openings were very nice, I didn't like their landings or their glide ratio. When I questioned PD about the landings, they did mention you have to "work it pretty hard" to get a good landing. Not to open old wounds in this thread, just repeating what I was told.

  5. Quote

    I disagre with the idea of jumping up and out, especailly on a somethig the size of an 8-way. It's going to take a second to get it all out of the door, and lay down a pretty big burble in the process. Try staying tight to the aircraft, and sliding down the side of the fuselage, presenting with a little rightward slide (on a left side door aircraft). This keeps you off to the side of the burble, so even if you're late on the exit, you're not far from clean air. By hopping up and out, you're hopping right into the dead zone.



    +1

  6. Keep in mind that different cameras have different fields of view before you even put a wide-angle lens on them. I find my CX150 to be much narrower than any of my previous jump cameras (HC-5, HVR-A1U, TRV-38, TRV-900, PC-1). I would look at the image before simply picking a number that a manufacturer states. The Raynox .32 on my CX150 produces a narrower image than my Raynox .50 on my HC-5. I personally wish I could find something a little wider that was still zoomable (although some don't use the zoom function).

    For a lens summary, check out this link from Hypoxic:
    http://www.gethypoxic.com/reviews/61-cx100.html

    BTW, I believe the CX series all have a 30mm thread, and most of these lenses require a 30-37mm adapter.

  7. Very nice, clean looking set-up. A couple of points:

    On my Wes Pro I was able to drill a hole from the front for the Hypeye and route the indicator through this hole from behind without having to remove the forehead padding (there are two indicators in this photo, one is behind the articulated bracket). For my blow switch tube, I was able to snake the tube through the chin padding but carefully poking a hole in it, without having to remove the entire chin padding.

    I have used a "multibit" drill bit to drill larger holes for buttons. They cut very clean in fiberglass and slowly step up in size. Plus you can get them at any hardware store. I would definitely put a back-strap behind the button to keep it from being pushed through.

    Better yet, using the Hypeye D Expansion kit, you can wire in a less bulky, smaller diameter button/switch, that is easier to locate, and is has an easier tactile feel when trying to push the button with gloves on.

    Lastly, I worry a little bit about the remote shutter wiring plug going in to your SLR. I can't tell how exposed your is from the photos, butI have sheared those off in the past, and since then always make sure they are well protected against riser strikes.

  8. I think that is really there just in case you need to mount/protect something super-wide. Mine is trimmed to the sides and back (as are most I have seen), but overhangs the front a little. The side screws are button screws and very snag-proof. In short, if you don't need the additional support on the sides, I would trim it flush and not worry about anything snagging.

  9. I agree on the connectors and the need for all that stuff on every jump. But as far as the 10-22mm lens goes, it really isn't that heavy. It is less than two ounces heavier than the Canon 15mm, and only 0.6 ounces heavier than the Sigma 15mm. Plus it doesn't have the annoying fish-eye effect. It is about an inch longer than either, but if I could afford one...

  10. I'll give you a short answer. First, yes, I totally believe ins getting everything up top, and credit doing so on my own helmet with reducing the wear and tear on my neck dramatically.

    Secondly, the most injury prone time of opening is the very end of the opening, when the canopy fully (and sometimes suddenly) inflates. At this stage in the opening, you are usually no longer belly to Earth, and instead your torso has already become mostly vertical (feet to Earth). At this point, any sudden deceleration will make that weight on top of your head compress your spine rather than lever it or bend it. On the other hand, any weight that is not centered inline with your spine (whether front-mounted or side-mounted), will act as a lever, pulling your neck out of line in one direction or the other, and causing injury.

    Disclaimer: I am not a doctor and do no even play one on TV.

  11. Hey Nicky (didn't know that was you). That block is really just a support for the lens to keep it secure and keep a line from getting under it. However it does help keep the foam in place (without the foam though, the block does nothing to get rid of wind noise).

    But with my CX150 and Raynox 3035, the bottom of the lens is practically flush with the bottom of the cam. So no similar support is needed, and the foam is wedged between the microphone and the bottom/front of the lens. I'll try to post a pic, or check it out this week at the DZ.

  12. On my helmet-mounted cameras (top-mount, no box), I use a piece of "pick-n-pluck," open-cell foam from a Pelican case. I try to use as big a piece as I can without having to compress it much, and I make sure it is right up against the microphone grille. It makes a dramatic decrease in wind noise (think of windscreens for hand-held vocal microphones). I often talk to my tandem student after my canopy opens (congratulate them, etc.). Without this foam, the audio is often unusable.

    Here is a picture of the foam on a Sony HC-5. the CX doesn't give you as much space, but there is still room for it.

  13. Not to mention several network TV dramas shot with DSLRs. For me, I like them for short form, talking head, instructional or low-light videos (IMHO, the Achilles heal of "camcorders"). And yes, the form-factor of DSLRs isn't great, particularly for run-and-gun work. But if you are setting up for a static shoot with tripod, monitor, maybe rods, etc., it isn't really a big deal. For concert/event videos, I have to use a video camera if for nothing else than just recording time. I'm sure large sensor video cameras will come down in price some day, but I can't wait for that now. There is nothing in my price range (yet) that comes close to a DSLR with a nice, fast prime lens. But I'm sure that will change eventually. Hell, it always does.

  15. You may want to find a mentor at your DZ for some beginning camera questions. Not trying to criticize, but if you weren't aware of the problems of using a DVD camera, it makes me wonder what else you may be missing. This person may also have lens recommendations, and/or a lens or two you can put on your camera to see what the resulting image looks like.

  17. Plus they are saying background rendering, native AVCHD, auto color-correction, easier L and J edits. I wouldn't rule out the other programs coming with it, but they haven't really said one way of the other. Nor have they mentioned upgrade pricing.

  18. I'd be very curious to see the actual video footage. I'll admit that I haven't done any DSLR video in freefall, but I have been doing more and more of it on the ground. Usually, high shutter speed on video is kinda jarring and stroboscopic (think of the D-Day beach scenes in saving Private Ryan). But in this case the ground looks almost sharper than the jumpers. How did you work out your focus settings? (Sorry if I'm asking too many questions, but this is a good comparison IMHO.)

  19. Well the colors and the dynamic range don't look close. The Canon has actual gray shades in the jump suits rather than just crushed blacks, and the greens in the background are very different. Plus look at the lack of detail in the far jumper's rig on the CX frame.

    The CX looks like it has its sharpening cranked way up, but both images look very soft. I'm curious what the shutter speed and aperture on the Canon were set to.

  21. Quote

    For exits, start off by getting off early. Go on the 'set' of the count. Tandems fall fast before the drogue comes out, so even if you get off early, their speed right out of the door will help you close the gap.



    I agree with most of what you wrote, but not this quote at all. Yes, tandems "fall" fast before they get the drogue out. But they are "falling" into the relative wind, which is the direction of flight. if you leave too soon, their additional speed will make them harder to catch, not easier.

  24. Just a thought... There is an option in your preferences to "Copy files to iTunes Folder when adding to library." Without that, it just references the file location and any change to the original source location may result in lost files.

  25. Keep in mind that the stock CX-110 is much narrower than many older Sony DV cameras. So an equivalent lens won't show as much of a field of view on the newer camera as it did on your old camera. i.e., you may need something more wide-angle to get the same image. You should see if you can try one out on YOUR camera before purchasing.