K20D Photo Count ?

Fl_Gulfer · 03-31-2009, 08:31 PM

I put a fresh SD card in (4g) and the count on the top LCD says I can take 272 shots but when I'm get to the card being full I end up shooting well over 400 shots, Why is this? I have it set on the best JPEG setting. Has anyone else noticed this?
Also is it bad to format you card instead of deleting each picture every time you clean your card?

RawheaD · 03-31-2009, 09:33 PM

Because unlike RAW files, JPEG files can have variable sizes depending on the amount of information in a frame that can be abbreviated.

For example, take a picture of a pure white wall; that's close to no information, so even at the same size/resolution, JPEG compression can bring the file size down a whole bunch. The shots remaining count, therefore, is just a guestimate, and it always is a guestimate.

Ole · 03-31-2009, 09:35 PM

It is best to format the card (in the camera) and get a "clean", unfragmented filesystem.

Jewelltrail · 03-31-2009, 10:06 PM

Quote:

Rawhead: Because unlike RAW files, JPEG files can have variable sizes depending on the amount of information in a frame that can be abbreviated.

I notice my PEFs vary a good deal in size too.

sevenarrow · 03-31-2009, 10:47 PM

I rarely do a DELETE ALL. I format my cards for every new photo session and after all the photos from the previous photo session have been successfully transferred to my computer and backed up on an external hard drive and on CD.

Fl_Gulfer · 04-01-2009, 06:48 AM

Smart answer, I didn't consider that a shot with half of it is blue sky would have less info.

My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe.
Thanks Again Guys
Jack

Mister Guy · 04-01-2009, 07:53 AM

Originally posted by Fl_Gulfer

Smart answer, I didn't consider that a shot with half of it is blue sky would have less info.

My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe.
Thanks Again Guys
Jack

The answer to that is either yes with a "but" or no with an "if".

Yes, it's bad in the sense that all flash memory has a limited lifespan, so the additional writes do technically make the card die sooner, but that's not a significant enough of a concern to change your behavior.

No, if you use your card like most people do, you're far more likely to have a failure that results in losing data from handling outside of the camera, and starting with a fresh file system gives you the best chance for data recovery and not having file system problems in the first place. Volatile memory is notoriously error prone, so improving your odds at the expense of a slight difference in expected life is a good trade.

OregonJim · 04-01-2009, 09:13 AM

Originally posted by Fl_Gulfer

My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe.
Thanks Again Guys
Jack

That was true with early cards made around the turn of the century. Modern cards have built-in wear-leveling algorithms to make sure that the entire card get used more or less"evenly". Given the price of cards vs. number of writes, the problem is really a non-issue.

Edvinas · 04-01-2009, 01:57 PM

Originally posted by OregonJim

That was true with early cards made around the turn of the century. Modern cards have built-in wear-leveling algorithms to make sure that the entire card get used more or less"evenly". Given the price of cards vs. number of writes, the problem is really a non-issue.

Very interesting information.

Do you know where I can read more about that?

OregonJim · 04-01-2009, 02:03 PM

Originally posted by Edvinas

Very interesting information.

Do you know where I can read more about that?

Sure. Here's a white paper from SanDisk. Wikipedia has some info, too - search for "wear leveling".

Arpe · 04-01-2009, 04:29 PM

With raw my K20D says I can take around 160. I add 80% to whatever it says as it always grossly underestimates. Even using my biggest raw would be more than 160 on the card.

03-31-2009, 08:31 PM	#1
Fl_Gulfer Veteran Member Join Date: Jul 2007 Location: Florida Gulfer Photos: Albums Posts: 3,054	K20D Photo Count ? I put a fresh SD card in (4g) and the count on the top LCD says I can take 272 shots but when I'm get to the card being full I end up shooting well over 400 shots, Why is this? I have it set on the best JPEG setting. Has anyone else noticed this? Also is it bad to format you card instead of deleting each picture every time you clean your card?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How to check shutter count on K20D	pakuchn	Troubleshooting and Beginner Help	13	02-06-2011 06:57 PM
For Sale - Sold: K20D Body in Canada, LOW shutter count.	ianinbc	Sold Items	3	11-17-2009 05:54 AM
New K20d Shutter Actuation Count Discrepancy	harleynitelite	Pentax DSLR Discussion	8	10-15-2009 12:46 PM
Illustration from a photo (does that count?)	thomasjmpark	Post Your Photos!	8	08-23-2008 03:52 PM
New k20d shutter count?	striker99	Pentax DSLR Discussion	6	04-19-2008 04:59 AM

03-31-2009, 09:33 PM	#2
RawheaD Veteran Member Join Date: Dec 2008 Location: MA, USA Photos: Gallery Posts: 831	Because unlike RAW files, JPEG files can have variable sizes depending on the amount of information in a frame that can be abbreviated. For example, take a picture of a pure white wall; that's close to no information, so even at the same size/resolution, JPEG compression can bring the file size down a whole bunch. The shots remaining count, therefore, is just a guestimate, and it always is a guestimate.

03-31-2009, 09:35 PM	#3
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,408	It is best to format the card (in the camera) and get a "clean", unfragmented filesystem.

03-31-2009, 10:06 PM	#4
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180	Quote: Rawhead: Because unlike RAW files, JPEG files can have variable sizes depending on the amount of information in a frame that can be abbreviated. I notice my PEFs vary a good deal in size too.

03-31-2009, 10:47 PM	#5
sevenarrow Forum Member Join Date: May 2007 Location: Colorado Springs, CO Photos: Gallery \| Albums Posts: 61	I rarely do a DELETE ALL. I format my cards for every new photo session and after all the photos from the previous photo session have been successfully transferred to my computer and backed up on an external hard drive and on CD.

04-01-2009, 06:48 AM	#6
Fl_Gulfer Veteran Member Join Date: Jul 2007 Location: Florida Gulfer Photos: Albums Posts: 3,054 Original Poster	Smart answer, I didn't consider that a shot with half of it is blue sky would have less info. My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe. Thanks Again Guys Jack

04-01-2009, 07:53 AM	#7
Mister Guy Senior Member Join Date: Jan 2009 Location: Raleigh, NC Posts: 244	Originally posted by Fl_Gulfer Smart answer, I didn't consider that a shot with half of it is blue sky would have less info. My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe. Thanks Again Guys Jack The answer to that is either yes with a "but" or no with an "if". Yes, it's bad in the sense that all flash memory has a limited lifespan, so the additional writes do technically make the card die sooner, but that's not a significant enough of a concern to change your behavior. No, if you use your card like most people do, you're far more likely to have a failure that results in losing data from handling outside of the camera, and starting with a fresh file system gives you the best chance for data recovery and not having file system problems in the first place. Volatile memory is notoriously error prone, so improving your odds at the expense of a slight difference in expected life is a good trade.

04-01-2009, 09:13 AM	#8
OregonJim Veteran Member Join Date: Mar 2009 Location: Willamette Valley, Oregon Posts: 1,327	Originally posted by Fl_Gulfer My College Photography teacher said is was bad for the cards to format them every time, and I found that hard to believe. Thanks Again Guys Jack That was true with early cards made around the turn of the century. Modern cards have built-in wear-leveling algorithms to make sure that the entire card get used more or less"evenly". Given the price of cards vs. number of writes, the problem is really a non-issue.

04-01-2009, 01:57 PM	#9
Edvinas Veteran Member Join Date: Sep 2006 Location: Kaunas Posts: 1,458	Originally posted by OregonJim That was true with early cards made around the turn of the century. Modern cards have built-in wear-leveling algorithms to make sure that the entire card get used more or less"evenly". Given the price of cards vs. number of writes, the problem is really a non-issue. Very interesting information. Do you know where I can read more about that?

04-01-2009, 02:03 PM	#10
OregonJim Veteran Member Join Date: Mar 2009 Location: Willamette Valley, Oregon Posts: 1,327	Originally posted by Edvinas Very interesting information. Do you know where I can read more about that? Sure. Here's a white paper from SanDisk. Wikipedia has some info, too - search for "wear leveling".

04-01-2009, 04:29 PM	#11
Arpe Pentaxian Join Date: Sep 2006 Location: New Zealand Photos: Gallery \| Albums Posts: 4,452	With raw my K20D says I can take around 160. I add 80% to whatever it says as it always grossly underestimates. Even using my biggest raw would be more than 160 on the card.

Thread Tools	Search this Thread
	Search this Thread: Advanced Search