The CRT301P is “cheap” radio trigger may by Yongnuo. The receivers have 2 basic modes
• Radio mode – triggering the remote flash unit by the CTR301P transmitter.
• Optical mode – triggering the slave flash unit by detecting the light of the master flash unit.
1. Ultra long working distance : This wireless sync flash transmitter and receiver can be operated up to “30m / 100 feet” using radio mode in an open area. In optical mode the range is up to “10m / 30 feet.” I know they work up to 5m but haven’t had the space or need to test them any furtherer
2. Choice of wireless modes : Radio signal or optical signal mode
3. LED indicator : LED on both the transmitter and receiver, the red LED light will blink at every trigger of the transmitter and receiver. 4.
4 wireless radio channels : 4 channels to optimise the connection and prevent interference.
5. Easy and convenient : Easy to get flash synchronisation without limits caused by connectors and cords.
6. One transmitter supports multiple receivers : The transmitter can control multiple receivers for triggering several system flashes or studio flash units at the same time. Multiple receivers can be used under optical mode also.
7. 1/4″ Tripod socket mount: The receiver includes a standard 1/4″ tripod socket available at the bottom of each receiver for fixing onto tripod or light stand.
I ordered 3 sets of Yongnuo CTR-301P Flash Triggers , because at the time there were no sets with 3 receivers. The sets I ordered have the Sony hot shoe on the transmitter and an ISO hot shoe on the receiver. Only 1 of the triggers works “properly”.
•1 will sync at 1/125th but not faster on any of my cameras.
• 1 will not sync during the exposure at all (even a 30 sec exposure) it always fires after the exposure is finished.
• The last one is brilliant it fire speeds up to 1/250th on my a900 and a700 no problem
There were very cheap and I only bought 3 sets because I wanted 3 receivers. But after testing them all I’m glad I got so many. I did contact the e-bay seller that sold them to me and they replayed fast but after 3 or 4 emails i gave up on trying to get the 2 defective transmitters exchanged.
As the receivers don’t have a a Sony hot shoe you will need an adaptor if you want to use Sony/Minolta flashes. I’m using them with old Nikon SB 28, 26, 24’s and my studio flashes. After a long period of use I haven’t had any major problems with miss fires. My Yongnuo CTR-301P are set to channel 3, as I also have a set of Cactus v3 set to channel 1.
They are very basic, and if you get a good set they are great. But IMHO the quality control is pathetic at best. And getting your set exchanged (from china) my cause headaches. If you only want a set to play around with and experiment with lighting thy will do the job. If need reliable triggers either order than 1 set or look a more reliable brand. Photokina is just around the corner and I will be going to look at the Pixel Pawn Soldier TF-373 for Sony. They may well be my next set of triggers.