Nikon D5100 External Flash

[createbeauty]

I have just upgraded from a Nikon D50 to a Nikon D5100. I have an external flash that I used on my D50 (Sunpak DigiFlash 2800) that sometimes works on my D5100. Sometimes the flash works just like on my D50 and other times the flash will go off but not at nearly the usual brightness as with my D50 (and occasionally on my D5100) and the pictures will come out dark.

Does anyone have any suggestions?

 

[jrizal]

Maybe your flash unit is already showing signs of age. Maybe it's time to get a new one like the Sunpak DF3000/Bower SFD728N/Neewer (they're all the same made in singapore but under different brands), a YongNuo or if you can swing it a Nikon branded one. But do check on the batteries also. Just my initial thoughts.

 

[jrizal]

Also check your exposure settings.

 

[SamitB]

Check flash /shutter speed sync settings too..