Sonntag, 11. Februar 2018

FPV Cam Latency

Download (or preview online!) the most current > XLS Latency Sheet
FPV Cams "Latency" or "LAG"

It is very important to see what your FPV plane/copter "sees" in REALTIME and react to eveade certain model death within milliseconds!

There is always some delay involved - but you should choose components to keep this minimal.
With high latency flying FPV feels like being drunk. Flying a non stabilized copter get's impossible soon - you fly worse than you actually need to. While you may not notice latency directly - without it you can become a better pilot. 

What components have an impact on latency?
+++ FPV cam:
Time from image capture (lens, chip) - to the output on the video cable.
Between those 2 events you have the image processing on the cams chip - so the right cam is important. See the Latency Excel Spreadsheet for most current measurements.

Older cams could add as much as 100ms of latency - this is REALLY a big deal!
Current cams are down as low as 5ms.
One problem here:
"unsharpness of measurement": each 16 or 20ms (NTSC or PAL) you get a new image. This means 60 or 50 pictures per second. it wont get faster than that (on analog video).
So everything below 16ms cant be directly measured. The moment you hit a signal (power on LED in my case) can be at a random position within this timespan of 16ms.
So I repeat many measurements and look for the lowest latency and the average - which is the probbability of seeing stuff the right time :)

+Video Transmission:
ANALOG transmission DOESNT use buffering. It doesnt use hightech chips that have to calculate a lot of stuff - it just transmits a power-signal (Video encoded in NTSC or PAL) over the air.
IT DOES THIS AT THE SPEED OF LIGHT!  (~ 300.000km/sec)
So the myth "over distance latency increases" is bullshit.
OK - if you're flying to the moon (384.400km) - it will get noticeable - but within reasonable distances you can forget it (each 300km would mean 1ms latency added).
I was able to measure video latency - but it's really in nano-seconds range on my oscilloscope :)

DIGITAL transmission however - this is another story. You have to ENCODE images (lots of them) into numbers - transmit them - and decode them on the other side. Clever minds try to make good algorithms and fast chips - but we're not there yet. Fastest systems are around 50ms - which is quite high compared to analoge vid...
See my review of the FPV Blue system - one of the most promising, very community interactive, projects that actually work, and can give great results!

++Control link:
So: you have a fast cam, see the obstacle (jumping tree, branch,...) asap - but HOW LONG does it take to convert the THUMB movement on your remote's stick to a control correction on the plane (servos) or copter (motor RPM change).
Drone Mesh did some good tests (also with osciloscope and decoding of signals on the screen).
I tried to test this myself - that's a lot of work - not finished my video to this - will update you. In the meantime whatch his videos!
No final results yet, it's a complicated matter - but I noticed the difference between ezUHF and Crossfire! - even between FrSky and Crossfire):
  FrSky 2.4ghz   20ms
  TBS Crossfire  12ms
  ezUHF              40ms  (but there is a lower latency mode I have to test yet!)

Latency testing method:
Better to probe the video cable (from CAM) directly, or measure the effect of the LED on the screen with a photo diode?
I decided to go back to the screen/photodiode method, because this is what you call "glass to glass" latency - the practical application for the enduser.
Additional benefit: This method allows us to compare digital and analog systems' latencies (since measuring video cable directly only works for analog).

Update 4/2018: in my last Video (Sparrow micro 2) I've come back to also testing cams "direct" with the video cable method. Newer cams can be tested for lantency very accurate now. Something has changed: on the video "curve" I see the light change immediatley - and not in "frame level accuracy". This takes away the 16-20ms inaccuracy. I saw that new cams like Foxeer Predator or Runcam Sparrow 2 have 1.3ms!!!

These are sketches of the two test methods (to maybe understand them easier):

see my video here for some closeups and details about the 2 test methods (starts around 03:00):

Also check "Drone Mesh" - he did quite similar testing here:

Changes to this blog in 2018!

I will stop publishing my youtube videos here with the same text as on youtube.
Rather this will be a place where written articles get posted (like technical articles that are harder to explain in a video - or additional writings to my videos).
I feel that just advertising for my videos doesn't add a lot of value to the community :)

Thanks for your visit here - also check out my other "hangar"-blog over there to see equipment posts.

Mittwoch, 20. Dezember 2017

Beautiful winter morning flight - MERRY XMAS! 🎄

Winter came just in time to get me into the right mood! I wish you guys a wonderful, silent, joyful, warm (but with snow) 🎄Christmas!! 🎄

Thanks for supporting 👍 my channel - please come back more often and I love to hear from you - a few words are so much more than just a view-counter going up...

Didnt fly the Mavic as often as I should have this year! Such a great device to capture the moment. Be airborne in minutes, capture steady footage that looks good. All the drone paranoia makes enjoying the hobby a bit difficult sometimes...

these were my last tries to capture this castle in winter:  (2010!)

Filmed with:  Samsung Galaxy S7
DJI Mavic

Natures Wonders 4 - Johannes Bornlöf
Compliments To The Piccolo 1 - Peter Sandberg

Mittwoch, 13. Dezember 2017

ISDT D2 Charger - really nice charger

you can buy it here:
Banggood sent me something for review! Again! They didnt blacklist me after my EV100 review :) And this product here is actually quite good! Check out my charger review if you are looking for a convenient way to send some juice into your packs.

UltraPower review:

!DISCLAIMER! - VENDOR/SHOP sent me this product for review
00:43 compared to other chargers (SIZE)
01:58 What's this for? Miniquad Batteries! :)
02:43 no external powersupply - really small package!
03:03 CONNECTORS (XH and XT60)
03:42 AC Power
04:03 tiny brother for mobile use...
05:27 TIP: use the little ISDT to empty your batts for storage!
06:11 CHARGING batteries - what do we see?
06:55 downside:  the scrollwhell isnt perfect
07:34 supported BATTERY types
10:39 LOOK and FEEL
11:43 final thoughts

Montag, 4. Dezember 2017

Foxeer Predator - the BEST FPV CAM out there? (Sparrow, Eagle2pro)

Please 👍 thanks ;-) (it helps my videos a lot!)
I've tested many cams, currently this is the best! Amazing WDR and lowest latency I measured til now. 1.8mm works well for me - but you need a large FOV on your goggles for such wide lenses!
If you like to have more options in your CAM - be able to switch between 4:3 to 16:9 or pal/ntsc - then go with the Eagle2pro. It has really good image as well and also a low latency.

!DISCLAIMER! - VENDOR/SHOP sent me this product for review, you can buy it here:
01:14 Closeup
01:34 Latency
01:50 Mount (Vortex Mojo mod)
02:23 get to the choppa!!!
03:13 side by side Predator vs Eagle2pro
03:31 high quality SD video samples (Sparrow, Predator)
03:58 Predator samples
05:15 awesome lighthandling on a sunny day!
06:21 dynamic range compared with Galaxy S7
06:57 tunnel
07:14 Lowlight
08:03 Menu options
08:41 flight with HD cam + Predator - Snow and Sun!
10:48 final thoughts, shout outs
...find the "bonus" audio feature at the end!!! and let me know that you did in the comments :)

Recording FPV Cams in HQ:
virtual dub (freeware to capture)
XVid Codec (for high quality and not extremly large files of uncompressed video)
some USB "Framegrabber" hardware (20$ on amazon or ebay)

Donnerstag, 30. November 2017

Mojo & the Golden Hour Mist

Sunsets are around 4pm here now, and foggy conditions in Nov make it hard to fly at all. So for a friday after work session I had to find a new spot, high enough to escape the fog. It's awesom if you can "bring home" this kind of footage with no issues. Once again enjoying the new Vortex and the reliable Crossfire.

Filmed with:  Vortex 230 and Foxeer Box (2560x1440x50fps)

Delicate Transitions - Gavin Luke
Compliments To The Piccolo 1 - Peter Sandberg

►my ⌘ COPTERS and ✈PLANES in the hangar

Freitag, 24. November 2017

ImmersionRC Vortex 230 Mojo Review, Testflights, install FrSky XSR and Crossfire, mods, Cam

ImmersionRC sent me their newest RTF Racequad. I spent many packs with it on my favourite testing grounds, flew in different conditions, once stock and later a bit modified (Crossfire).
You see how easy it is to install the Radio RX. Later I switched to crossfire micro - so this is also a mini review about the popular Radio control link from Trappy / TBS.

00:33 QUADMOVR!   Awesome LOS flying
01:01 FPV maidenflight, PIP with DVR footage of stock cam and Foxeer Box
03:12 first THOUGHTS after flying a few packs
04:44 LOWLIGHT testflight with stock FPV cam
05:29 2nd session with the Vortex on Eichberg - sunny!
06:32 will Runcam2 fit?
07:32 flight footage montage
10:18 THOUGHTS after some more packs flewn
11:34 TIPS
11:49 INSTALL FrSky XSR RX (easy!)
12:36 closeup of cam
15:24 Taranis screens for Crossfire setup (OPENTX2.2)
16:19 TIP: TX Wizard von the Vortex - doesnt work if throttle is disabled
17:14 Crossfire antennamount

Weight of the system?  384gr (copter except HD Cam and Battery)

If you wanna see the Vortex TX Wizard in action, check out my Vortex250 review - it didnt change much - and it's also quite self explanatory!
!DISCLAIMER! - VENDOR/SHOP sent me this product for review, it costs around 380€ in shops.
Crossfire TX module is ~ 100€     the Crossfire micro RX ~45€

Filmed with:  Samsung Galaxy S7
Foxeer Box
Runcam Swift 2

Molife Forever - Jack Elphick
Compliments To The Piccolo 1 - Peter Sandberg

►my ⌘ COPTERS and ✈PLANES in the hangar
║ ►BLOG:

Freitag, 17. November 2017

Runcam Split 2 follow up and flight footage on Vortex 150 (sub 250gr!)

There were many questions after my initial quick review of the new Runcam Split 2 - so this is the followup. Short: yes, latency is really good, Quality nice - good improvement over version 1! VIDEO INDEX below! !DISCLAIMER! - VENDOR/SHOP sent me this product for review, you can buy it here

filmed with Samsung Galaxy S7
Runcam Split 2

00:09 liveout latency (effect of different options on latency?)
01:00 solderpad vs USB connection?
02:13 softmounts (for board or cam?)
02:45 SD CARD slot V2 - better? YES!!!
04:47 menu settings (Tips)
05:41 liveout in 4:3 or 16:9
05:53 - latency test - latency of DIODE? accuracy?
07:21 my CONCLUSION on the Split 2
Runcam video tutorial - use FC to control Split:

00:55 Hangar review
03:15 footage (home)
05:13 lowlight footage
06:05 in the woods!
08:31 with ND Filter at the graveyard...

Donnerstag, 2. November 2017

FPV in the woods with digital transmission (FPV Blue, RC Car)

This is the followup to my hangar review of the FPV.Blue HD video transmission system. First flew with a quad, later moved on to an RC Car to test penetration of RC signal in the dense woods. What a fun! Finally driving around from inside my hangar...

●▬▬VIDEO INDEX:▬▬▬▬▬▬▬▬▬▬▬▬●
00:31 testflight with TBS Disco and FPV.Blue
01:52 swap gear to RC CAR (short overview)
02:28 FPV in the WOODS with RC Car
02:24  some directly recorded FOOTAGE
06:03 filmed from screen from here on
06:41 the gravel road, distance, passers, dogs,...
07:24 MAP of first distance test (~150m)
07:54 DOG :)
08:46 second distance test IN THE WOODS
09:21 to the flightfield!
10:04 WDR fail in bad light conditions...
10:45 WOODS overview
11:49 BETTER Screen recordings (sharp) from HANGAR
13:08 Chihuahua chased :)
13:39 father in law chased :)  ("roadkill")
14:49 lowlight example with WDR on - noisy

Thread on RCG:

Filmed with:  Panasonic GX8 + R0de VideoMicro, Samsung Galaxy S7, Yi 4k
Thanks PETER for filming ext shots, thanks CHARLIE for letting me chase him  (the Chihuahua) and thanks to my lovely guide in the woods!

Brand New Beginning - Gavin Luke
Fifteen - Aldenmark Niklasson
Compliments To The Piccolo 1 - Peter Sandberg

Dienstag, 24. Oktober 2017

Digital HD video downlink! (Interview with FPV Blue, long range low latency)

We're waiting for some serious HD video transmission now for a few years. Connex prosight was promising and is still the most used? - ok Lightbridge and Occusync from DJI are market leader - but they have very high latency...
For "real" FPV usage we need lower latency, reliability, range. All being promised by a small, dedicated company - FPV.Blue.

Join me in the hangar for a closer look at this new system, check out the menu options, see the latency measured, and see me interviewing Davide from FPV.Blue.

!DISCLAIMER! - FPV.Blue sent me this product for review, you can buy it here
●▬▬VIDEO INDEX▬▬▬▬▬▬▬▬▬▬▬▬●
00:00 FPV Blue - system overview
01:30 Receiver (diversity)
03:04 CLOSEUPs
03:32 SD Card recording?
04:55 Transmitter
06:02 HD Cam
06:52 Transmitter closeup
07:19 Antennas
08:08 Spectrum Analyzer
08:34 MENU OPTIONS-----------
08:50 - Video input
09:44 - Modulation (transmission settings)
11:19 - Display settings (Bluesync)
12:30 OSD
13:50 LATENCY (Eachine Goggles 2, Black Pearl, DJI Goggles
15:32 INTERVIEW with Davide from FPV.Blue
16:01 - background, company...
16:37 - shipping times
18:03 - Antennas
18:19 - Goggles tested...
18:47 - 2.4Ghz and 5.8Ghz Versions?
20:15 my conclusion
21:16 some short footage clips (more in next video)

Thread on RCG:
FPV Latency compared to other systems:

Antenna recommendation:
why CP antennas are not neccessary:

Groundstation Recordings (a bit troublesome to work with as of 16.Oct.2017 - should be improved with next firmware):
can be played back with MPLAYER  
there's also a GUI version (SMPLAYER)
Recordings do not get corrupt when power is lost

Bonafidepirate: 14km flight
first video, thoughts