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?