My 4gb sd card showing only 30 mb how to get again 4gb

Your camera should be capable to record video for 30 minutes in a row. The SD card should be more than 4Gb to record 30 minutes. and not 128 Mb.
I think you have a 128 Gb card, if not the card is the problem. 128 mb is really not enough for 30 minutes. It would be just enough for one and a half minute.

1 GB = 1024 MB (mega bytes)
1 MB =1024 KB (kilobytes)
1 KB = 1024 bytes
1 GB = 1024*1024*1024 bytes
1 GB = 1073741824 bytes

But manufacturers count 1GB as 1000000000 bytes, so it's normal that a sd card which advertise being 4GB is in reality 3.7GB (4000000000 / 1024 / 1024 / 1024 = 3.72 GB).

Sure. Simply use a larger card. The ZR600 will work with any SD card. Be careful to get an SD card and not an SDHC card. SD cards go up to 2GB (2000MB) in size. SDHC cards look identical but start at 4GB but will not work with this camera.

The SD200 works with SD cards. Your 4GB card is actually an SDHC card. While it fits into the slot, it is electronically incompatible and will not work in this camera. You need to use SD cards, 2GB and smaller.

my sd card is of 2gb but its size is showing only 45.6 mb
please give me solution on [email protected] or on 9560709358

The Optio S4 works with MMC and SD cards. Your 4GB card is actually an SDHC card. While it fits into the slot, it is electronically incompatible. You need to go with cards 2GB and smaller.

The 3200 works with SD cards. Your 4GB cards is actually an SDHC card, which is electronically incompatible. You need to use SD cards, 2GB and smaller.

The Z700 works with SD cards. Your 4GB card is actually an SDHC card (the HC stands for High Capacity) and will not work in the Z700. You'll have to stay with SD cards 2GB and smaller.

this model u cant use more than 1 gb

the reason for your problem is that the rd2312 can only handle a 1 gb card