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Aerial Videography and Photography Aerial Video/Photo from R/C Helicopters |
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10-08-2009, 05:03 AM | #21 (permalink) |
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OK,
I went for my second plan (training with a cheaper heli first) I bought a used T-rex 450, and a new futaba T7C. I'll test fly it during this weekend if nothing goes wrong when setting up the heli. I'll report later |
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10-08-2009, 11:20 AM | #22 (permalink) |
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Good choice! Two weeks ago, I inherited a used trex 450 v2 from my dad. So far there have been 3 crashes, it has not cost more than $100 to repair yet. ( for all 3) the key is confidence, don't listen to all of these people trying to scare you and tell you it is so much harder than the sim. The more confidence you have the better you are going to do. Like I said I have been at it for two weeks, and now I'm practicing flips, stall turns, tail slides and rolls. All because I let go of the fear everyone else put in me. Be confident! If you can do it in the sim, you really can do it! ( but make sure you are using the 450 on the sim otherwise the differences will be a bit big) Now get out there and knock their socks off!
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10-19-2009, 01:19 PM | #23 (permalink) |
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OK, so I bought the 450!
Just wanted you how my project is going. Here is a small clip from my 6th flight A lot of vibrations, and a reeaaalllly bad and old pocket camera... http://www.youtube.com/watch?v=y6iRE...er_profilepage flying wasn't so hard that i thought it should be, it was harder in realflight than in reallife! Thanks again for the advice! |
10-20-2009, 01:26 AM | #24 (permalink) | |
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-The heli itself vibrates a lot at very high frequency -You can not install too large a mount so there is not too much room for vibration dampening -You can only use a light camera which in turn tend to vibrate easily at high frequency With a big heli that vibrates only little at low frequency you can install a big mount with good vib damping and a big & heavy camera. Heavier the mass, lower the vibration frequency and less the amplitude. Win win. |
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11-09-2009, 10:22 AM | #25 (permalink) | |
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11-10-2009, 12:57 AM | #26 (permalink) |
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Blokkies, Forget the 250's, far too twitchy, 450's are bad enough....and you will be very limited as to what you can lift. For starting out the Trex450 is OK, I used one with the Infinity Hobby mount, http://www.infinity-hobby.com/main/p...513ca80665795f . How ever since I got my Trex 600 set up I haven't touched the 450!! Soooo much smoooother to fly and I regularly fly in 20MPH winds with ease! And if you want to do videoing, I strongly recomend a VholdR ContourHD cam, There awsome!!! Here is the 2nd flight from my Trex600(raw footage- excuse the crappy flying 15-20 mph winds).
http://www.vholdr.com/node/50960 Paul. |
11-10-2009, 01:33 AM | #27 (permalink) |
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>> I strongly recomend a VholdR ContourHD cam<<
Sorry I beg to differ. I have the Contour HD and it cannot compare to the Panasonic Lumix LX-3 in video. The Contour HD uses CMOS sensor and a rolling shutter. The LX 3 has CCD sensor and it not subjected to the waviness when vibration is present. |
11-10-2009, 02:58 PM | #28 (permalink) | |||
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Regarding the camera, I had a look at the Contour site and they look pretty sweet and it's intended application seems to be a good fit for aerial videography. I like the design, and at 60fps, quality looks very nice. The debate between CCD and CMOS is an old legacy one that originates from the early sensor development 40 years ago. From what I've seen so far I don't think it matters. "you can find CCDs in low-cost low-power cellphone cameras and CMOS sensors in high-performance professional and industrial cameras, directly contradicting the early stereotypes" http://www.dalsa.com/corp/markets/CCD_vs_CMOS.aspx Cheers, Michael |
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11-10-2009, 08:55 PM | #29 (permalink) |
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>>The debate between CCD and CMOS is an old legacy one that originates from the early sensor development 40 years ago. From what I've seen so far I don't think it matters. <<
Believe what you like. Just don't come back here asking how to get rid of the waviness in your video when you use a CMOS sensor camera. Look at the sample vides in this site. http://www.dvxuser.com/jason/CMOS-CCD/ It is really about the rolling shutter. |
11-10-2009, 09:22 PM | #30 (permalink) | |
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What exactly have you seen? I can assure you there is a SIGNIFICANT difference. Have you personally purchased CMOS and CCD cameras and tried them against one another? I've tried alot of them and the CMOS fails over the CCD every time. I feel qualified to make that statement. I'm a video editor, videographer, motion graphics animator with nearly 17 years experience shooting broadcast video for an ABC News affiliate in both studio and live settings. Spent several years producing motion graphics and compositing video for a Fox affiliate, and the last 13 years as Chief Editor for a large TV & Print advertising firm. I don't make a habit of throwing out credentials, but in this case I want it to be understood that I feel confident in my statements regarding CMOS vs. CCD. The white paper you reference in your link says nothing of the practical use of the output from CMOS cameras. Technically speaking the CMOS chip is the "superior" chip. In a room full of techno-geeks the CMOS comes out the winner. But in real world "practical" use you'd see a room full of professional videographers and DP's pushing for the CCD. This is of course assumign the CMOS camera in question has a rollling shutter (which ALL consumer cameras have) vs. the global shutter. It is interesting that the company which you linked to manufactures a global shutter CMOS camera. On this page from the same company they discuss the pitfalls of the CMOS due to rolling shutter. http://www.dalsa.com/mv/knowledge/globalshutter.aspx here is n excerpt from a .pdf located on the same site: " CCDs can deliver superior electronic shuttering, with little fill-factor compromise, even in small-pixel image sensors. Implementing uniform electronic shuttering in CMOS imagers requires a number of transistors in each pixel. A nonuniform shutter, called a rolling shutter, exposes different lines of an array at different times. It reduces the number of in-pixel transistors, improving fill factor. This is sometimes acceptable for consumer imaging, but in higher-performance applications, object motion manifests as a distorted image. A uniform synchronous shutter, sometimes called a nonrolling shutter, exposes all pixels of the array at the same time. Object motion stops with no distortion, but this approach consumes pixel area because it re- quires extra transistors in each pixel. Users must choose between low fill factor and small pixels on a small, less-expensive image sensor, or large pixels with much higher fill factor on a larger, more costly image sensor. " If you have and you've found a rolling shutter CMOS camera that does not exhibit the rolling shutter effect (paradoxical sounding, I know), I (and many others) would sure like to know what camera that might be. |
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11-10-2009, 09:34 PM | #31 (permalink) |
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The statement that CCD versus CMOS doesn't matter is pretty true for many stills photographers. Canon make some of the finest SLRs available, but use CMOS. They got a lot of flack for it because of the prejudice that real photographers use CCDs.
AP is a different issue because of vibrations, but there are a lot of people using Canon equipment on larger helis. Last edited by wlfk; 11-11-2009 at 06:54 AM.. |
11-10-2009, 09:47 PM | #32 (permalink) |
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LOL, now you get DJ's attention. ;-) Then again some one who also believes the Trex 250 create acceptable video footage is not very selective regarding the quality of the video image either. The HD Contour is simply a video camera designed as a light weight camera to mount on a helmet for the adrenalin junkies. Not for aerial photography from an RC helicopter.
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11-10-2009, 11:52 PM | #33 (permalink) |
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holy crap that fpv was from a 250? with 6 mins of flying? Thats quiet the range that baby has.
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11-11-2009, 05:30 AM | #34 (permalink) | |
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11-11-2009, 08:18 AM | #35 (permalink) |
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Shazam says Planisphere (part 1) - Justice
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Robert - DJIUSA.com N. A. Dist. for DJI Innovations USA Dist. for Photohigher USA Dist. for Vario (Industrial) |
11-11-2009, 10:56 PM | #36 (permalink) |
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That is some INSANE FPV coming from a 250. Imagine you're out mowing the lawn and this little bullet zooms by over your head. I was waiting for a splat into a garage door or chimney
I too would much rather use a CCD over a CMOS for AV. The CMOS sensor in my Nikon D5000 is completely useless for any type of motion. Tip
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11-12-2009, 12:26 AM | #37 (permalink) |
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Note, I did not say CMOS video cameras are better than CCD ones, chill out. My background is in still photography not video so I don't dispute that there are amazing video cameras out there using CCD's, but to say CMOS cameras are incapable of achieving good video from an RC heli is completely false.
Below is a link to some beautiful HD AP videos from an RC heli ALL recorded on CMOS video cameras, Sony and Canon. The last one is a full frame SLR camera from Canon, 5D Mk2. All the videos are HD 1280x720 so they will take a few minutes to dowload but well worth waiting for, smooth and beautfully done, not to mention the fantastic RC heli control of the pilot. Recommend #10 - #16. http://homepage1.nifty.com/CUE/html/main_fset_e.htm Please don't comment on this if you haven't taken the time to at least look at one of the videos.
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11-12-2009, 12:51 AM | #38 (permalink) | |
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I've seen all the video from CUE. Been watching him for years. Yes the video is good, but if you look closely you can still find CMOS artifacts.... albeit less pronounced than typical.
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I never stated that. I'll leave the conversation as this..... get yourself a rolling shutter CMOS HD camera and shoot some footage. Report back with your results. I and others would be anxious to see the excellent results that rolling shutter CMOS cameras can provide. Then after you've tried CMOS and decide you may want to try CCD come back and share your thoughts on that as well. Actually I think I'll offer an "X-Prize" of sorts. The first person that can show me video from a 600+ class helicopter shot from a rolling shutter CMOS camera that exhibits no anomalies inherent with rolling shutters and also shoots with a camera similar to Panasonic SD9 (3CCD) the same footage and can draw a conclusion that the CMOS is no worse or even better than CCD, I'll offer a major discount on a 2XPT front mount system. I'm dying to find a CMOS camera that will work as well as my Panasonic 3CCD cameras. |
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11-12-2009, 01:16 AM | #39 (permalink) |
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>>Note, I did not say CMOS video cameras are better than CCD ones, chill out.<<
Michael I think you need to listen more on the forum before jumping to conclusion and passing out false information. People may read your post thinking that you are some sort of AP guru stating that the Contour HD is a good video camera just because you looked at their video online. >>"From what I've seen so far I don't think it matters."<< This is the kind of statement that should be be posted if you don't know. Some newbie may read it and go out to buy a Contour HD only to find out that it is not giving him the result that he desired. >> My background is in still photography not video so I don't dispute that there are amazing video cameras out there using CCD's, but to say CMOS cameras are incapable of achieving good video from an RC heli is completely false.<< Now, you wait a minute. We have a lot of professional people on this forum and every one agrees that at this time 11/11/2009 you simply cannot use any production CMOS video camera and produce a smooth "wave free" video footage from a production RC helicopter that is in existent. Not saying that CCD is better than CMOS or the other way around. It is a FACT that the current crop of high definitely video camera uses rolling shutter to expose the CMOS sensor. Take a 5DMk2 if you have one since you are in the still photography business. Now, take a video and pan really fast while the video is on. Show me the footage and I will show you what a rolling shutter is. My back ground is also in photography. I having been doing it for the last 40 years. I fly radio control models and have been flying continuously since 1968. From your post you have not even flown a radio control helicopter and is looking at a Trex 250 as a trainer. Please have some humility and listen to the more experienced. >>Below is a link to some beautiful HD AP videos from an RC heli ALL recorded on CMOS video cameras, Sony and Canon. The last one is a full frame SLR camera from Canon, 5D Mk2. All the videos are HD 1280x720 so they will take a few minutes to dowload but well worth waiting for, smooth and beautfully done, not to mention the fantastic RC heli control of the pilot.<< Please look closely at the website and look at how many of those footages were shot on a fixed wing aircraft and how many were shot on a RC helicopter. I only saw one footage that is shot with the Sony HDR CX12. Yes I have that camera also besides the Contour HD. Also a Panasonic HS9 and the SD9. I also have the Lumix LX3 and the Nikon D90. I have shot video footages from all of them. I can do it again if necessary. DJ makes camera mounts and gimbals professionally. He has to know what works and what doesn't work to help his customers. >>Please don't comment on this if you haven't taken the time to at least look at one of the videos.<< Just because you have the time to sit in front of your computer Googling video footage doesn't make you any more knowledgeable than other experts here. These experts get their experience by actually spending the money to buy the equipment and doing it instead of sitting around like an armchair pilot. |
11-12-2009, 09:29 AM | #40 (permalink) |
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Rolling shutter has an effect on more than just vibrations, so let me explain. It's not about the CMOS or CCD per se, but about the rolling shutter. I won't even go into video, let's just focus on what happens physically when a camera takes a still shot. For the purposes of capture, video is just doing this repeatedly. If you take a picture with any camera, with a large fast-moving object in view, you want to capture the whole scene at the same time.
Example: a propeller is rotating in view of the camera. Frame shutter: propeller looks realistic, straight, maybe blurred a little at the tips depending on exposure time. Rolling shutter: propeller looks like a boomerang or even shows up as multiple parts, some of which are disconnected from the hub. Exhibit: from a CMOS iPhone camera with rolling shutter. Example: the camera itself is being panned left or right. Frame shutter: scene looks realistic, blurred in the direction of motion but all buildings look firm. Rolling shutter: scene looks skewed into a parallelogram. Exhibits: from a CCD DSLR with physical frame shutter and a CMOS point and shoot with electronic rolling shutter, both panned on the same tripod at the same time. http://techthoughts.org/2009/09/09/cmos-ccd-test/ Example: vibrations. If the camera itself is being moved in any direction other than panning, similar artifacts are created if the scene is not captured entirely at the same moment. The sensor is very small, and individual photosites are microscopic. Moving the camera by even a microscopic amount between the beginning and end of the image capture will distort features in the scene. Did not find any existing examples of someone doing vibrations while taking a picture of a tile floor, but found this exhibit: from a CMOS iPhone with a rolling shutter, being twisted by hand during the image capture. Again, CMOS and CCD both collect excellent light, for most situations. One method of image retention, the rolling shutter, is commonly used on CMOS sensors, but has a problem with fast-moving scenes, such as vibration or panning. Incidentally, a CCD or CMOS camera with poor video algorithms can very easily produce different motion artifacts in the video compression process, such as a juddering while panning. Any camera should be tested in likely scenarios before adopting for a particular purpose or recommending to other shoppers. |
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