Cheap Monitor

[jimbo385]

I went and bought one of these monitors on Ebay. Only £31 including postage! Hope it';s good. 

Will see just how good it is for FPV. All I need now is a TX & RX!

[robshaw]

Will you be flying fpv from inside your car? Nice. 

[Leigh]

Please do let us know how it goes - interested to know if it has the blue screen on signal loss or if that can be disabled, and how brightness goes in sunlight :)

[teslahed]

I recently bought myself one of these;



for about £33 from ebay;

http://www.ebay.co.uk/itm/140949217415?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

but it hasn';t arrived yet so i haven';t been able to test it.

It';s got a higher resolution than most but unfortunately i think it does the blue screen thing on signal lose.

I am going to test a method for preventing this. I think it might be possible to use a super simple OSD on the ground side video to measure the battery voltage and display that in the video feed. This would give some warning if the battery was about to run flat, but it would also mean that even when there was no video signal being received the screen would still be receiving a video signal from at least the OSD showing the battery voltage and a timer, so the blue screen would never activate.

http://www.hobbyking.com/hobbyking/store/__16662__HobbyKing_E_OSD.html

[Cozp83]

I';ve got the same monitor teslahed. It does go blue but the video gets all shitty first. It kinda flicks between blue and video feed for a bit then goes blue. I just reverse when it starts to break up.

[jimbo385]

I';ll give it a good test and let you know.

[jimbo385]

Well, I hooked up the monitor and yes, I';m afraid that it is very good!  :evil

It does however display a blue screen with no signal but I bought a very cheap Sea Wolf camera and the display is spot on!

I took my manual hookup into a field and was very impressed!

The camera has a wide angle lens and a focusing ring so I can manually set the field of view. Can';t wait to get my TX & RX and hook the lot up!

[teslahed]

I';ve got the same monitor teslahed. It does go blue but the video gets all shitty first. It kinda flicks between blue and video feed for a bit then goes blue. I just reverse when it starts to break up.

I have tested the blue screen on mine by leaving my hex on inside and walking outside then behind another house. Incredibly i was still getting video through two sets of stone walls. Like yours the video was almost total static before it blue screened - i would have crashed due to static before i crashed due to the blue screen if i';d been flying in those conditions.

So i';m happy with the performance at the moment. I might still try the OSD groundside mod to stop it bluescreening eventually but i';m not in a hurry to do that now.

I think i may need to refocus my FPV camera lense. I wasn';t noticing the fuzz before.

[jimbo385]

Well, I';ve set mine up with the inexpensive 5.3ghz RX & Tx from Hobby king and I';m getting a blue screen every now and then close to the TX. When I move away, the blue screen is still there but far less.

I';ve tested on the ground and am getting a max of about 200m! This is with the stock antennas. Is this aboutright?

[teslahed]

200m with stock antennas probably is about right. You should get much better than that with even some cheap hobbyking 5.8GHz skew planar antennas and if you go for Gavs you';ll get even better performance!

http://www.multi-rotor.co.uk/index.php?topic=3871.0

[jimbo385]

Will it stop my monitor from getting Blue Screen?

This is a real pain as it takes a few seconds to come back and by that time I could be quite a way and a totally different attitude from that expected which would most likely end in a crash!

Thanks.

[teslahed]

Better reception will mean you are less likely to see the bluescreen but when your reception goes you';ll still get that effect.

You need to put something in between the screen and the receiver that will keep a signal going even when the receiver loses the signal.

If you use a dvr and if it has a throughput you can put that between the receiver and the screen and it may prevent the bluescreen showing by keeping a signal going at all times.

Alternatively you could look at getting a super simple OSD from hobbyking, wiring it up to the lipo battery your receiver runs off of and feeding the video signal from that into the feed between the receiver and the screen. This will warn you when your receiver voltage is dropping and by doing so will stop you ever seeing a blue screen.

http://www.hobbyking.com/hobbyking/store/__16662__HobbyKing_E_OSD.html

Or buy a new screen that doesn';t blue screen. Some don';t.

http://www.multi-rotor.co.uk/index.php?topic=3278.0

[jimbo385]

Cheers Ross. 

[Ross]

Cheers Ross. 

Did you buy one?

I know they cost more but for a non blot out screen and HD I suppose it';s best.  Ha';pth of tar and all that  

[teslahed]

Ha';pth of tar and all that

I had to look that one up to understand the proverb. I thought you were speaking klingon then for a second

http://www.answers.com/topic/do-not-spoil-the-ship-for-a-ha-porth-of-tar

But it';s a good point

[steve fh]

My experience with cheap monitors is the same.

IE picture break to the point at which you could not be flying fpv long before it they go to blue screen.

By far the biggest issue i see with FPV is the signal loss (particularly with 5.8ghz) if you fly behind a large tree or building. At that point even a non blue screen monitor will display static and you can';t fly on static.

Resolution, Brightness and high contrast ratio are by far the more important features on a monitor from useability point of view than blue screen

I have tested the blue screen on mine by leaving my hex on inside and walking outside then behind another house. Incredibly i was still getting video through two sets of stone walls. Like yours the video was almost total static before it blue screened - i would have crashed due to static before i crashed due to the blue screen if i';d been flying in those conditions.

[teslahed]

My experience with cheap monitors is the same.

Resolution, Brightness and high contrast ratio are by far the more important features on a monitor from useability point of view than blue screen

I suspect that not all blue screening monitors are the same. Some may have the bluescreen threshold set lower or higher than others. So if you get one that you know bluescreens it is a good idea to test how easily that occurs before flying using it. Maybe we';ve both been lucky.

I would be interested to know what kind of brightness and contrast settings you pick to get best results? Do you crank both up to max, leave them at defaults or do you have another method?

I';ve not played about with these settings as much as i should really, and there are a load more brightness and contrast settings i can fiddle with via the FPV camera';s OSD itself (mine has a separate breakout board i have to attach to do this).

[steve fh]

Hi Chris.

The contrast ratio is part of the spec of the monitor and is a big part in how well it copes in bright sun light.

the typical cheap £25/30  units i have from ebay are 100:1 or 200:1 ratio

If you look at the spec of the more pricey monitors such as the one Field View from Hobby King then the ratio is in the region of 500:1 which as i understand it makes it more usable in bright light.

As you say the camera set up is a big factor as well. On my cheap CCD $10 board camera from HK the picture is very poor compared the same monitor if the feed is from the gopro av out.

[jimbo385]

Well, I am in the market for some Planar antenna';s but which one? I';m not quite sure that skill level justifies a massive outlay. Also, I';m more concerned about damage to them through storage and transportation.

So, has anyone a suggestion on some quality antennas where the clover is protected?

With regards to an OSD that can be used on the RX end to help with stopping a blue screen, what about this from Hobbyking?

http://www.hobbyking.com/hobbyking/store/__36844__Minim_OSD_v1_1.html

Cheers.

[kilby]

From memory the ratio you mention is tge contrast between  black and 100% white (most important on screens wgich require backlighting)

Yes high contrast improves your viewing, however there should also be a lumens value for the actual brightness of the screen

[steve fh]

From memory the ratio you mention is tge contrast between  black and 100% white (most important on screens wgich require backlighting)

Yes high contrast improves your viewing, however there should also be a lumens value for the actual brightness of the screen

yep all the higher spec screens quote this.

[Ross]

If its any interest...
The FEELGOOD non blue out 7" monitor I bought has

Contrast ration of 500:1.
Brightness 400cd sq m
Resolution 800x3 (RGB) x 480
The 8" type has  same contrast with a 450cd brightness and same resolution.

(Specs from the handbook).

Monitor cost  £70. free postage as mentioned elsewhere on this forum.

[powerlord]

you';d be better with a 4:3 monitor though surely ?

A 16:9 is just going to show a distorted picture (yuk) or black bars either side.

Also, make sure you check the specs when buying a cheap one, as Ross eludes to, some quote horizontal resolution in subpixels only - just to make it look better than it is.

So for example you might see: 960x200 resolution quoted.

which is mince - it is actually 320x200 as they are counting each R,G and B pixel.

stu