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gibson1525
10-29-2007, 20:32
I just spent some extra $ (not too much) for a SD memory card that was 133X over slower speeds. i like the card and it seems to write very fast as i can take pictures as fast as my strobe will recycle (which is almost continuously at the beginning of the dive).

my question-does the card speed really make that much of a difference?

bversteegh
10-29-2007, 22:53
Depends on your camera and how big the buffer is. DSLR's have a big enough buffer to take a series of shots stored in the buffer, while the camera writes the data to the card.

Most cameras can't write at anywhere near 133x (x = .15 MB/sec, so 133 is ~ 20MB/sec), most Point and Shoot cameras write between 1.5 to 3 MB/sec - so anything over 50x is probably overkill (I would buy at least 50X because of inflated speed claims by card manufacturers). DSLR's are approximately twice as fast - but have a big buffer so aren't limited by write speed unless you try to shoot more than 10 -15 shots in a row.

RonFrank
10-29-2007, 23:16
High end DSLR's are handling data at the rate of 185 MB/sec in the case of the new Canon 1Ds-mark III. That thing can shoot 5 frames per second up to 56 frames before things have to catch up. The camera is too new to know all the details, but that's some blazing speed.

So there is an example of a camera that can push those high end cards. However PnS camera's are slow, and most are no where near the speed of a high end card.

But what sells. NUMBERS! More MPIX, higher card speeds! Neither translates into higher performance necessarily.

Aussie
10-30-2007, 06:13
I just spent some extra $ (not too much) for a SD memory card that was 133X over slower speeds. i like the card and it seems to write very fast as i can take pictures as fast as my strobe will recycle (which is almost continuously at the beginning of the dive).

my question-does the card speed really make that much of a difference?

I have to agree with bversteegh in regards to the size of the buffer of the camera your using. dSLR's have large buffers to handle higher frame rates and also file sizes (ie Raw).

I believe you can notice the difference more in memory card speed when your transfering the data from the card to the PC. Even more noticalbe are the new SDHC format of SD memory cards. Sandisk provide a card reader with their new SDHC cards.

It does come down to numbers like RonFrank said. Especailly when there is high end cameras with 21mp image size and high frame rates. The need for faster cards and huge memory will soon catch up. Probably go towards wireless (belive some camera have now). Where your camera will transfer to a wireless harddive for your shots.

Aussie

gibson1525
10-30-2007, 07:30
so i probably was wasting my money as i just have a sea & sea 8000g. i can't wait to make the jump to DSLR!

another question-i'm using rechargeable energizer 2500s in my strobe. they recharge pretty quickly. i was just wondering what the best battery was for a quick recharge.


thanks for the help

Aussie
10-30-2007, 08:25
so i probably was wasting my money as i just have a sea & sea 8000g. i can't wait to make the jump to DSLR!

another question-i'm using rechargeable energizer 2500s in my strobe. they recharge pretty quickly. i was just wondering what the best battery was for a quick recharge.


thanks for the help

I think it then comes down to the charger. I used to use the Energizers for my Ikelite DS50 strobe. The charger ( Energizer brand)I had took a few hours. Then they brought out a quick charger which took less than a hour.

I just had a dozen of the Energizer batteries and rotated them around. One set in use, one set ready to go, and one set on the charger. Now I do the same but with the batteries for the Ikelite DS125.

I think after a while the Energizers loose their capacity to hold a good charge and have to be replaced.

Aussie

RonFrank
10-30-2007, 09:21
so i probably was wasting my money as i just have a sea & sea 8000g. i can't wait to make the jump to DSLR!

another question-i'm using rechargeable energizer 2500s in my strobe. they recharge pretty quickly. i was just wondering what the best battery was for a quick recharge.


thanks for the help

Skip the ultra quick recharge chargers. They have to overheat the battery, and most (maybe all) don't provide full charges. My research is a few years old, but I don't think things have changed that much.

You will have to do some research, but I like PowerEx MAHA charges. They were rated as some of the best chargers when I did my research for both reasonable speed, battery conditioning, and providing a full charge.

THIS (http://thomasdistributing.com/shop/product_info.php?cPath=147_149_152&products_id=288&SP_id=45&osCsid=0614b693ef93ac5dbdb7ab0dc2106454) is what I'm currently using.

If you are worried about charge times, buy more batteries, don't go with a 1 hour charger that will likely reduce the battery life and capacity.

When I was doing research on this the BEST charge was obtained by using a 2 hour charger, and then topping off the batteries with a trickle charge. Ironically the trickle charges by themselves were the cheapest, and some of the best, but while 2 hours is not a horrible wait to recharge batteries, overnight is unacceptable for most.

gibson1525
10-30-2007, 10:56
thanks, right now i'm just using the 8 hour charger that came with the batteries. i'm not doing any liveaboards right now so time is not a huge deal. i have 3 sets and rotate them. i put in one after getting back from morning diving and one overnight and it works for me.

i'm going to be doing a lot more dives/day over christmas in the bahamas and bonaire so i guess i should probably look into a 2 hour charger. thanks for the advice

bversteegh
10-30-2007, 12:30
If you buy a new charger, make sure you get the "worldwide" model. I have 2 chargers that only work on 110V, worthless overseas where most of the power is 220 V:smiley19:

gibson1525
10-31-2007, 15:33
always a good idea, i've been there before. thanks

gtoph
10-31-2007, 23:37
You will have to do some research, but I like PowerEx MAHA charges. They were rated as some of the best chargers when I did my research for both reasonable speed, battery conditioning, and providing a full charge.


I agree, the the PowerEx batteries seem to do a good job of holding up their charge. I have a set of the 2700 mAh in my strobe and they last forever... along with using the right charger. I'm using the MAHA C9000 charger, which has a whole conditioning cycle it can run on them and you can select how fast or slow you want them to charge.

You can find all sorts of info on the "correct" way to charge batteries, but I do firmly believe that a "quick" charge will lower the life of the battery (though too slow isn't good either). You just need to find a happy place in the middle....I like to charge it around .25C to .4C, which in the case of my 2700's takes around 3 to 4 hours. In general, I'd say 4 hours, give or take an hour, is a nice area to shoot for a charge rate.

On another note, I think I saw you have the same camera as I do (S&S 8000G?). If you haven't already, I would pick up the lithium ion battery pack for it as well. Of course I would always bring a charger just incase, but just to see how long it would last, I fully charged it at the beginning of the week and it finally gave out about half way through the last dive of the trip a week later.... not bad for 350+ pictures and the LCD on nearly the whole time.

gibson1525
11-01-2007, 07:24
well, i have an interesting question this morning. my wife went diving yesterday and took the camera. i got home a few hours after she got back and discovered that something had happened to the strobe, it looked like a battery had exploded. there was a small amount of liquid in the strobe and all 4 AA batteries were very corroded. she said the strobe worked the entire time, so i don't think it flooded. anybody ever heard of this?

gibson1525
11-01-2007, 07:27
On another note, I think I saw you have the same camera as I do (S&S 8000G?). If you haven't already, I would pick up the lithium ion battery pack for it as well. Of course I would always bring a charger just incase, but just to see how long it would last, I fully charged it at the beginning of the week and it finally gave out about half way through the last dive of the trip a week later.... not bad for 350+ pictures and the LCD on nearly the whole time.


yes, i bought 2 when i bought the camera only to find out that they last forever. what a nice surprise.

gtoph
11-01-2007, 10:47
yes, i bought 2 when i bought the camera only to find out that they last forever. what a nice surprise.

Heh, funny. I bought 2 as well thinking, I'll leave one in the charger so it's ready to go just incase the other takes a while to recharge or lasts only a day. Owell, who knew. :)

gtoph
11-01-2007, 10:51
well, i have an interesting question this morning. my wife went diving yesterday and took the camera. i got home a few hours after she got back and discovered that something had happened to the strobe, it looked like a battery had exploded. there was a small amount of liquid in the strobe and all 4 AA batteries were very corroded. she said the strobe worked the entire time, so i don't think it flooded. anybody ever heard of this?

I'm no expert at all, but taking a guess, I would say you did have a leak which corroded the batteries. I haven't seen a battery "release" a liquid like you describe. They do give of a little hydrogen when they charge/discharge, but that's a gas... but like I say, I'm no expert. :)

gibson1525
11-01-2007, 13:22
I'm no expert at all, but taking a guess, I would say you did have a leak which corroded the batteries. I haven't seen a battery "release" a liquid like you describe. They do give of a little hydrogen when they charge/discharge, but that's a gas... but like I say, I'm no expert. :)


yea, i've never heard of them leaking either. i just thought the did becuase there was a LOT of corrosioin, i don't think that would occur with just water, i think it would take battery acid to do that kind of damage. not a big deal i guess since i tried the strobe again and it works.

bversteegh
11-04-2007, 01:04
Even if it works on the surface, I would check it for leaks under pressure (just take it down to the bottom of a pool) without batteries inside before taking it on a dive. Just a little leak (especially salt water) shorts things out, and causes the batteries to corrode, and possible leak. I had a similar problem in an Ikelite strobe - and figured out I had a small leak that was causing the problem.