[Aerial Mapping] What is best Sony Nex 5 setting for Aerial Mapping mission?

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:

Recommendations:

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

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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

Very well noted 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 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.

My photos came out too dark when the camera chose the aperture. I also found AP works the best on the Sony Nex.

Hi Moglos,

Interested with your setup, so you are using below setting if I'm not mistaken interpreting your post:

  • Mode: Shutter Priority
  • ISO: ?? Around 200 - 400 perhaps?

Please elaborate more..

When you use aperture mode you have more control over exposure and picture quality.

"Nearly all lenses have lower contrast and are less sharp at their widest aperture, especially towards the corners of your image. This is especially true on 35mm and digital camera lenses. On sharpness, this is a totally separate issue from depth of field; this will happen even with a flat subject. Consequently, if you're going to have detail in the corners of your pictures that you want to keep sharp, then you'll want to use a smaller aperture. For flat subjects, f/8 is typically the sharpest aperture."

It is from http://www.wikihow.com/Use-Your-Camera%27s-Aperture-Priority-Mode  (Point No3)

It seems that Nex5 with 16mm lens has the best performance with F8 (check this site http://www.photozone.de/sony-alpha-aps-c-lens-tests/542-sony16f28ne...).

They say about:

1.Vignetting

2.MTF (Resolution)

3.Chromatic abberations (CAs)

I use shutter priority mode. As a rule I use 800 for multi rotor (fast because there is heaps of vibration), 800 for fixed wing below say 60m (fast because they move quite fast), 600 for fixed wing above 60m (can get away with slower shutter because the ground movement looks slower from the point of view of the camera)

ISO - according to test results. I take a straight down photo of the ground (or something that represents what I'm photographing) and see what the aperture was for that photo. Then I'd adjust the ISO to give me a mid range aperture (say 6-8). That leaves enough room for it to move if the light conditions change. I'm happy to set the ISO up to 1600. You still don't get much noise.

Good point about F8 being the sharpest. I remember reading other users that found that out themselves. Still I think getting the shutter speed wrong is more serious. (Point 6 on the wikihow page you linked suggests using the biggest aperture you can for hand held shooting.)

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.

After some pretty serious testing I use the following (for a NEX 5T with 19mm Sigma, but pretty much the same)

DMF or manual focus

f/8 - f/9

1/800 or faster, depending on sun conditions

ISO 400-800

RAW only

Aperture is the most important - I was having loads of issues with bad focus, and having a smaller aperture gives you a much larger depth of field. I set the focus on a far off object before I take off. I haven't had any issues with ISO 800 in sunny or partly cloudy conditions, although shadows will have a bit of noise. I switched to shooting RAW and will never go back - you can do so much to the pictures after you take them, and even without editing Lightroom exports cleaner, sharper JPGs than the camera does. This also allows for lens corrections, adjusting exposure, eliminating ISO, changing color balance... I had issues where if it became cloudy during a flight, my settings would be off. However, you can just bump up the exposure and change the color balance so all your images are matched if you shoot in RAW.

I also find that the 19mm Sigma lens takes better pictures than the 16mm pancake, and it is cheaper. It is a bit longer by a bit, but not much.

I've also just been shooting with the intervalometer but am going to start using an IR trigger soon. It's really easy to GPS tag your pictures after the fact, and the flight controller GPS is probably better than the S100s anyway. The Canons aren't even worth messing with, IMO, the NEX 5 takes way better pictures, and requires far fewer to cover an area.

David,
I gather from your post that you are in full Manual, and that you compensate for the shadows by using RAW and post production. Have you had poor success with Aperture Priority?
I agree that the 16mm pancake stinks. I had a terrible time with it. I switched to the 30mm Sigma and it works great. I haven't tried the 19mm, but after your recommendation I will look into it.

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