i had this doubt for some days now and couldnt get the answers so........
Q) why is a 6ch or more channel tx required for fpv??
according to me 4ch or 5ch tx should do if you dont add any gimbal/servo which has to be controlled by the rest of the extra channels
so why are people saying that 5th and 6th channels is necessary for fpving?
thanks for looking in this thread
 

Most of the people who fly FPV on multi rotors use an autopilot which requires one dedicated channel to change flight modes and one channel for controlling camera gimbal. No one would risk to fly in pure manual/stabilize mode with all the gear attached unless they have excellent flying skills. So it is obvious that a minimum 6 channel radio is generally preferred over a 4 or 5 ch one.

appreciate those words but what if i dont want a gimbal(250quad)

It depends on which flight controller you will be using then? CC3D, Naze32, Mini APM has flight modes which are to be configured so minimum 5 channels are required for that.

so the 5 th channel is just for changing modes??? or it can be used for something else too?

See Darshan, I have a 6 ch radio, and I use it for flying a quad with fpv and gimbal. I use Naza. For me, 4 channels are used for the Thro, yaw, pitch and roll. 5th channel, the gear channel, along with some mixes used for changing between GPS-ATTI-Manual modes. 6th channel I configured for controling the gimbal pitch. So you need atleast 5 channel. 6 or more would be better to utilize all the features.

okay thanks

Updated to a meaningful topic name.

Thank you Anwar sir
Still looking for more input though

What more details you need Darshan? Its pretty simple. If you just want to fly your multi in one single mode even with fpv and gimbal, 4 channels will do. But if you want to pitch or roll your gimbal or want to toggle between auto and manual modes you need more channels. More the channels more you can explore. So better to go for higher channel rx-tx. Just for simple fpv you do not need any channel.
Now for pro aerial photography some use a separate receiver and transmitter which is dedicated to the gimbal and camera control. That is entirely a different scenario.

I would be upgrading to fpv soon(after final exams) so can you guys suggest the cheapest fpv things required so I can start of with fpv
Thanks

You can try boscam. They are more or less cheap and good in performance.

5.8 ghz boscam is GOOD to start with in fpv Just make sure to use good quality cloverleaf antennas with the and you will do fine

What else will I need if I buy this kit?
http://www.quadkopters.com/product/fpv-kit-and-accessories/fpv-kit-5-8g-200mw-av-txrx-system-with-sony-ccd-420tvl-camera/

GOOD cloverleaf antenna
An fpv goggle fatshark or anything else like diy hobbyking goggle
You CAN also use a monitor but goggle will be more comfirtable
That's all

What do you mean by a monitor
Do you mean any led screen like a very small TV (types) or do you mean I can use my iPad or something like that as a screen

I would say since this is your first fpv, instead of a goggle go for a 7 inch LCD monitor. This way you can see the quad as well as the live feed. But with goggles you can only view the live feed. I would suggest go for Boscam RX LCD 5802 monitor.
http://www.banggood.com/Boscam-RX-LCD-5802-5_8GHz-LCD-Diversity-Receiver-7-Inch-Monitor-p-908273.html

It is a compact device all in one, receiver, monitor, battery, antenna. No need of attaching rx to monitor, lipo to power up receiver and monitor. It has a search option so just switch on and you are ready to receive signal and display the live feed. You just have to buy a transmitter. Yes, a bit expensive than the individual setup.

AFAIK, Ipad can be used with DJI products which has their dedicated app to view. But normally a 7" lcd monitor is sufficient for viewing. Youtube has lots of videos related to FPV.

Also check this lcd monitor available at the same online store.
http://www.quadkopters.com/product/fpv-kit-and-accessories/7-tft-lcd-dashboard/

Yes! A monitor with built in receiver & battery is better choice as mentioned above by meet2ami 

 what about this thing ---hobbyking.com/hobbyking/store/__53706__Quanum_DIY_FPV_Goggle_Set_with_Monitor_KIT_.html.       

There is no problem in using video goggles as long you have a spotter nearby.

these diy goggles does work like fatshark goggles or there is difference ?

According to what I understand till now ,
A monitor is an lcd screen having power,video,audio inputs and an rx to get the transmitted video waves and display
Please correct me if I am going wrong

@ Darshan You are correct partially. Not all monitors have in built receivers and battery. Like the Boscam RX LCD 5802 monitor has an inbuilt rx and battery where as the monitor in quadkopters.com does not have any rx or battery in built. It is just a display with A/v input. You will be needing a receiver and a lipo. Ofcourse it is much cheaper.

@Nite These quanum goggles are cheaper solution to fatshark. These are more bulky and heavy. Most importantly you need a receiver and battery to connect to these goggles which is not required in case of fatshark goggles.

Is there a special kind of a rx ? Can anybody post a link showing it?

Darshan, what is your requirement and your budget for adding FPV gear?

@meet2ami    thanks a lot but what would you prefer for a newbie or beginner as like me or darshan, quanum or fatshark ?? because main thing is quality .. as i can buy both of them but if quanum goggles have same quality as like fatshark soo i would prefer quanum because in 15k we can setup fpv with quanum and on the other hand fatshark comes as a kit at around 30k +  (not a budget friendly) or we can say this it a one time investment in fatshark?    

is there any other option available in market for fatshark like copies of it or from boscom or any other good company under 20k ?

Well firstly tell us, have you built your multirotor? If yes how is your multi flying and how confident are you as a multi pilot? See flying with goggles on is not an easy task. You have to know the movements of your multi very well before going into fpv flight. So I would suggest 1st practice your flight with a lcd monitor where you can have a visual to both the multi and the live feed. When you are confident with that then move to goggles. Thats what I feel. And always fly in an open place with less obstruction.

yes i own a zmr250 and now i have an idea of all controls and  can do acro easily now soo there is no problem i think in doing fpv now and i have used couple of fpv simulators also for practicing

If you want to do racing stuff with your 250 size quad then video goggles are better option than monitor. Other brands like Skyzone goggles are available but even they cost a lot. Check the link and decide for yourself. But remember that the video what you get won't be HD.
http://hobbyking.com/hobbyking/store/__539__543__FPV_Aerial_Video_Telemetry-Goggles.html

Also check this youtube video with quantum fpv goggles put to test with 250 size quad. It might help you to decide.

Yes, if you are confident and want to go for racing, then goggles are better option. Start with the cheaper one's as suggested by phanivyas rather than the expensive fatsharks and skyzones. The quanum v2 is a good option to start with. Also you can use the 5 inch lcd display separately if you want.

Is this kit available in india?

thankssssss a lot ... @phanivyas and @meet2ami ...       will go with your suggestion

@nite You are most welcome.

@Darshan Not sure about the quanum v2 as shown in the video. But the older version is available. Here is one:
http://robu.in/shop/quanum-diy-fpv-goggle-set-with-monitor-kit/