Dear All,
I was using Cannon S100 previously for mapping purpose with CHDK, 1/2000 shutter speed, IS turned off and focus set to Infinity but still get around 50% blurry image.
Now I will use Sony Nex 5n camera on Flatmap1 gimbal with 16mm stock fixed lens and IR triggered from APM for more ground coverage and quality image (hope so..)
Please share your Nex 5n camera setting (Auto or manual or shutter priority?) and any experiences, pros & cons using Nex 5n for mapping purpose.
Let me start from what I was reading from some forum (forgot the link):
Sony Nex 5 series Camera Setting for Mapping:
- Mode: Aperture Priority (by Krajst)
- ISO: 400 or 800 (by Krajst) (if you want faster shutter speeds, you'll have to increase your ISO) check: http://www.wikihow.com/Use-Your-Digital-Camera%27s-ISO-Setting
- White balance: Daily/Sunny or Cloudy (by Krajst)
- Sharpness: infinity (but it is tricky with 16mm lens so I use auto (by Krajst)
Recommendations:
- IR Shutter from Hobbyking (by iskess)
- Use high speed SD: SANDISK EXTREME PRO SDHC SD 16GB, 95MB/s (by iskess)
Pros:
- More pixel compare with S100 = More ground coverage
- Fixed lens 16mm = less blurry image result
- ??
Cons:
- Heavier compare with S100
- No GPS onboard
- Nex 5n Time between shutter > 2 sec = S100 faster < 2 sec (if you need to fly really fast)
- ??
I will update first page regularly that may be useful for others.
Many thanks in advance for your contribution.
Waladi
Replies
That is correct. I haven't used aperture priority, mostly because I want to keep the shutter speed high. I haven't had any issues with manual, so I've continued to use it. I have been lightening up shadows with post-production, but the RAW allows me to shoot in manual without worrying about lighting changes.
You had told me previously that you liked the 30mm - I may pick one up so I can still fly high and get good GSD. I've had some issues reproducing buildings with the 19mm, since I fly fairly low (lots of perspective change).
David, do you process the image one by one or do you batch process them?
Thanks,
I batch process by similar characteristics. For example, if half of a set is cloudy, I'll do that half separately, and alter the temperature, exposure, and blacks more than I would otherwise. It's pretty easy to get them close enough that Photoscan can deal with them - I mostly worry about matching amount of green color when doing grass/forested areas. Haven't done as many urban or suburban areas yet.
I had the same problem as you did with blurry images on the S100 and any other Canon camera with optical image stabilization. There's several discussions on this topic in the forums. Bottom line is that if you want to use Canon and CHDK you need to use a camera without optical image stabilization. I've had very good success with the Canon SD900 using CHDK in burst mode. The pictures are just as good as my NEX 5N (although the field of view is narrower), it is less than half the weight, and it costs 1/10th the price on eBay.
On my NEX 5n I use the following settings:
Aperture Priority
f Stop 5.6
Shutter - Automatic
ISO 200
AWB
Metering – Center
Focus Mode – Continuous
JPG only, no RAW
The reasons for the settings are;
I want the fastest shutter speed consistent with sharp images without pixel noise.
In testing the 16mm pancake lens that I use I found that an aperture below f5.6 produces soft images (when mounted on a tripod to insure no camera movement). I couldn't see any differences between f5.6 and about f11, above that it started getting soft again.
Above ISO 200 I started seeing noise in the dark areas
Focus is impossible to adjust manually with the 16mm lens.
When the 5n is in the "Remote Commander" mode the first two images can be taken quite fast, after that you are limited to one image about every 2-3 seconds whether you use the IR trigger or the manual shutter release. Saving RAW would cause this to be even slower.
I use the Flytron sLED IR shutter release. After some initial problems with it when using a Pixhawk I found that it works well provided that you power it with 3.3 volts rather than 5 volts. There is an undocumented requirement that the PWM signal voltage matches the power voltage and with the Pixhawk that's 3.3. On an APM that's probably 5v.
Hi Waladi, I think this is a good discussion around the Sony choice.
Maybe you should take one step back and try to look at different reasons why the Canon is giving you blurry images. Have you looked at your airframe and ruled out all possible mechanical reasons - motor, prop, servo vibration ect. Is there not a part of the airframe that starts to oscillate at your cruise speed?
Is the camera mounted with dampeners between it and the fuse?
Have a look at you log files and see if you are experiencing excessive vibration during flight.
Good luck,
Antonie
Will put your points on the recommendation sections.
I was using tarot motor and yes it produce so much vibration, tried to balance it with iphone vibration apps until I can mount the APM with only 1 layer of double-sided 3M tape with reasonable vibration range in the APM, and it fly really well with Y6 and mountain wind gusting from up hill.
And yet again same result, and even others were claim they had faulty S100 because after taking all of precautions on the multirotor aspects, still almost same result achieved.
About gimbal, there will always other side of hard-core DIY-ers which is my self included and it's not bad at all.. But then again, I would rather spend time to perfect the result compare with little tweaks here and there that I also love most..
Hi Antonie,
Yes you maybe right, at that time when I was decided to change the camera was because (in my lack of knowledge) i had tried different multirotor frame and motor combination with almost identical results (most of the image was blurry) and many people had the same problem as mine and strange enough some others having relatively good image.
I'm always using multirotor and never had any plane experience, so perhaps different result were achieved using planes.
I just (again my lack on knowledge) assume that "floating lens" from Canon was the cause and change it with other camera and finally use Nex since it was already in my shelf.
Do you have any luck with S100?
Buddy, I'm using a S2300. I've built 2 H-frame copters with fairly big fuse's(They look like C130's :)) - so I do not fly in much wind. I went through the process of tracking and eliminating vibrations and are reaching a point where I can derive some decent results from my flights - also time to upgrade my camera since the 2300 was my training wheels. First I had the motor arms mounted in silicone foam through the fuse. This seemed OK, but caused some control issues for the APM since it could not react to movement it did not sense. I glue-gunned those to be rigid with the fuse and focussed on the motors and props. I'm using HK's 5017 motors (http://www.hobbyking.com/hobbyking/store/__41485__Turnigy_5017_620k...) with Afro 30A Esc's and PixHawk - the ESC's run warm to hot, I'll have to replace these with 40's or 50's. I use the 5000mah 50C battery. One of the main sources of vibration was the prop mount and shaft's. They are truly crap for multi's. Pinching a prop onto a shaft caused many issues. I switched to T-Style props and it is a different world. The prop screws onto the motor bell removing many vibration issues. I use 13x5.5 T style carbons with the motors above. I have hover at about 35 to 40% throttle, so in theory I can load the bird with quite a bit more mah. I have about 15 to 17 minutes flight time in auto mode in fair conditions. My camera is mounted in silicone foam. I don't use a gimbal....yet - cant believe those chaps wants $150 for that gimbal. You can make that for 20% of the asking price. 2 servos, 4 bearings and some composite sheeting - $150 really?
I fly at 50 or 60m relative altitude at a speed of 4 or 5 m/s. I maintain copter orientation through the waypoints. I do not exceed 10 minute mission planning time. I do not cover a huge area at a time. My camera uses the Canon hack's intervalometer with an interval set at 0 seconds.
That's where I'm at. I believe killing the vibrations in the airframe is key to good results. Balance your props, balance the motor bells (Yeah, I know - easier said than done) and put your camera on dampeners.
Good luck
Antonie
For mapping I use:
Mode: Aperture Priority
ISO: 400 or 800 (if you want faster shutter speeds, you'll have to increase your ISO, check it http://www.wikihow.com/Use-Your-Digital-Camera%27s-ISO-Setting)
White balance: Daily/Sunny or Cloudy
It would be good to set the sharpness at infinity, but it is tricky with 16mm lens, so I use auto.
Hi Krajst
Is there a reason you don't just use shutter priority? You can set the shutter speed set exactly how you want it. That's what I do on my fixed wing and multi rotor. I find it's best to set ISO manually otherwise the camera tries to set the lowest ISO possible, which means it opens the aperture right up (low number) which isn't good for depth of field.
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