What kind of relay do I need to get?

[Jacobrblocker]

I am just starting out this year with the whole light show thing and i see lots of people on youtube us normal relays, but i have also seen people say to get SSRs. I am going to be using a MEGA and probably 8 lights. I was thinking about one of these relays https://www.amazon.com/gp/product/B0...=ATVPDKIKX0DER or https://www.amazon.com/gp/product/B0...A1A5FQE7R5RISB . I was wanting to be able to dim at least a little. Also dont i need a serial to usb to make dimming work or do i just plug the MEGA in normal.

I will be using mostly norm bulbs for now and i am 60hz.

[LightUp]

The link you provided shows a SSR that can not dim. It is strictly on or off.
The dimming data is provided by your sequencer, like Vixen, or xlights, etc.
Since you plan to use incans, you will need a SSR board and another circuit called zero crossing detector to let your Arduino know that the AC line has crossed zero volts. For more on dimming read this article; http://playground.arduino.cc/Main/ACPhaseControl Also look in our wiki.

[Jacobrblocker]

would i need to do all of that work if i just got a norm relay?

[LightUp]

would i need to do all of that work if i just got a norm relay?

"Norm" relay meaning mechanical? They can't dim either.
To dim you need to divide each 1/2 AC cycle into "x" time slots, which is usually 256 time slots. This allows you to create a pulse width modulation of 120HZ, or 100HZ - depending on your line frequency. Your triac needs to turn ON on one of these time slots, therefore your Arduino needs to know where in the time sequence it is. This is determined by the Arduino getting an interrupt every time the AC line voltage goes through the zero voltage point. The circuit is called a zero crossing detector. The firmware then updates all the lights during every time slot.

[kev]

If you just want to have flashing/blinking lights, the second board you listed above should work fine. You could then use the VictorPerez sketch found on this site. You obviously would still need to assemble your MEGA, SSR boards, power supplies and lights.
Most of my show songs use just flashing/ blinking. Some have some fading. I think you would have lots of enjoyment with flashing/blinking this year and then add fading next year if you desired.

[Jacobrblocker]

Ok thanks for the help i will just do blinking this year.

[Pcguy17]

It sounds like your doing about what I am this year, I am getting a raspberry pi and going to run the falcon player on it and im making sqences using vixen 3.0 or whatever the latest is.. going to stick my files and mp3s in the rasp.pi and run my show.. I am excited to be able to use my own music..
How do you plan to hook your lights to the rely board? are you going to do regular outlets like in a box of some sort? this seems to be how most do it. but im thinking why couldn't we just run short drop cords cut short straight to the rely then just have those connected to plug lights straight up.. I kinda dont want to use regular outlets just not sure it could be done like that.
btw this is the one i ordered but im not sure what im doing lol. i figured if i can get 8 to work i will order another to make it 16
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1