SD card help please...

[Bugleone]

Greetings one an all!....my first post so please be kind

Since starting to use my Sony NEX 3 in June '11 I have only used 'ordinary' SD memory cards. The results have been very encouraging (despite formerly being a medium and large format film user) and I now have some very nice 20x16 inch prints with two currently in an exhibition.

The cards I have used are 'Scandisk' and 'Lexar' purchased from reputable suppliers. However, two days ago I began useing a 'Scandisk ULTRA' and now have considerable noise in the files..... This is approx equal at 400iso to using the 'ordinary' cards at 1600iso....

Does anyone have any specific knowlwedge about this please?

[Black Pearl]

Nowt to do with the card. All they are doing is recording 1's and 0's - something else has changed when you put it in, check all your settings.

[Bugleone]

I take the point about the purely digital nature of the set up, but, no, that's no it as I have made side by side tests from the same subject....

[russellsnr]

Hi, Welcome to the forums.
Not by any means an expert but try formating the card in camera again, assume you did format the card on the first use.
Looking forward to seeing your photographs.
Russ

[Bugleone]

Russel (&Robin) thanks for the replies,..it's a bit of a mystery to me as to why,...could the 'ULTRA' card strore the data in a different way perhaps for speed? I've been getting excellent results from the ordinary 'scandisk' cards;

[Inkanyezi]

I assume that your card label says SanDisk and not Scandisk.

No, no card can influence the "graininess" (noise) of the image. If you take the same subject with the same settings under the same lighting, the result should be the same. Exposure makes a lot more difference, and faintly exposed parts of an image are always more noisy than those that have received a good deal of exposure.

There are also issues with the image chip temperature that may change noise production while you are working; a hotter chip will render more noise than a cool chip, so often when taking series of pictures, the first ones are less noisy than somewhat later. The difference is seldom noticeable, but if the exposure is on the low side, it may be significant. But also in this case, the memory card will not influence noisiness, perceived as "grain".

So if there are differences, you have to look elsewhere; there's nothing with the storage.

[Andrew1]

It could be a faulty interface but my first guess is you have a knock-off card. There are lots around. Send it to Sandisk for confirmation. You'll get a new one if it's theirs. Looking on the internet, Peak Development is the UK distributor.

[Photon Hacker]

Russel (&Robin) thanks for the replies,..it's a bit of a mystery to me as to why,...could the 'ULTRA' card strore the data in a different way perhaps for speed? I've been getting excellent results from the ordinary 'scandisk' cards;

As users we're not concerned for how the storage medium does its work (Namely, to assign discrete values to points on an addressing space specific to that device, or whatever your favorite interpretation is), it should be transparent for us. Whatever is stored should be returned as-is when requested, otherwise the storage medium is defective and should be replaced. Several storage devices internally use a layer of error correction between its interface and the physical storage medium to account for possible corruption on it; virtually all modern hard disks drives do, also the so called ECC (Error Correction Code) memory modules. Note not all failures of the underlying physical medium are necessarily due to manufacturing defects or wear and tear. For instance, ionizing radiation can easily corrupt DRAM cells.

It is possible for the memory card to be corrupting the stored data. Even if All they are doing is recording 1's and 0's. How corruption would show depends on the format you're using. It's unlikely (But not impossible) for it to appear like high sensitivity noise, especially for a compressed image. We can imagine a case in which the image is encoded as raw pixel values (Not necessarily the case with the camera's RAW format) where the memory card splits the recorded data at the byte level to different zones in the card, and the zone which stores the least significant bits of the images happened to be defective but the file system structures are not affected . Then the least significant bits in the image will be random resembling noise. I would be surprised if this were the case.

If the memory card causes the problem It seems more likely to me that it would be because of its electrical characteristics. Maybe it has a too harsh power consumption for the camera's power supply and the associated voltage noise feed to the ADC shows as high sensitivity noise.

Have you made two photographs with the new card and another one with the old one of the same subject with the same settings and as close in time as possible?. If so, post it. We can't help you if you don't help yourself.

Also bear in mind correlation does not imply causation!.

Good luck!.

[Marty]

Lovely picture Bugleone !

[enaiman]

Here is the simple test: copy one image (using your computer) from your " good card" to your "bad card" then open that image from both places. Compare them.
If you don't see a difference then your new card is good.
It would be even better to do it both ways (copy image from bad to good and compare again).

If the result is bad - send it back.

[Dave Humphries]

Hi Bugleone,

The only electrical explanation I can think of as to why an image from a card would appear noisier is if one of digital 'low' bits (where noise is), is also tied (by an internal electrical short circuit) to a 'higher' level bit (normally used for the brighter parts of an image), thus 'superimposing' the noise at a much higher level.

Basically this means the Extreme card may be faulty, so do check exactly as Eugen suggests.
Sending it back (especially if faulty) will soon illicit a response from SanDisk if it is a 'knock off' card.

I use SanDisk cards exclusively, mostly "Ultra II" and some "Extreme III" and, so far, no problems

One request; please Edit your Profile and pop a first name into the Real Name slot please - we're not like other forums, we're more friendly and friends address each other by first names - thanks.

Welcome to the CiC forums from ....

[Marty]

Hi Bugleone,
.......Sending it back (especially if faulty) will soon illicit a response from SanDisk if it is a 'knock off' card..

Yes, I can confirm that Sandisk is very good at responding. About 3 years ago I bought a Sandisk card on eBay (from an eBay shop with 99% reputation/feedback). Within a week or so the card was corrupting my pictures and no amount of formatting would clear the problem. I sent it to Sandisk and they were very helpful. It turned out that the card was a cheap fake, although all of the branding, badging and packaging was genuine Sandisk!! They were very pleased that I'd (inadvertently) brought this fakery to their attention and they sent me 3 new genuine cards as a 'thank-you'!