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Gear Talk => Canon General => Topic started by: Kiboko on January 22, 2012, 01:54:03 PM

Title: Never delete images 'in camera'
Post by: Kiboko on January 22, 2012, 01:54:03 PM
Got a shocked telling off from a friend of mine when I deleted an image I'd taken on his brand new 7D.  He told me it was possible to damage the processor by deleting images from the memory card 'in camera'. ONLY delete the images off the card when the card is being read on a computer, he told me. Never heard THAT before, and can't quite believe it. Is this true? If so, why? - and surely Canon wouldn't provide a 'delete' button!
Title: Re: Never delete images 'in camera'
Post by: Mt Spokane Photography on January 22, 2012, 02:02:33 PM
There is no problem deleting images while in your camera, many photographers do this all the time.  Its certainly not going to damage your processor.  I'd take anything your friend says about photography with a grain of salt from now on.

However, unless you need desparately to make more space on your card, I'd just transfer all the files to a computer and then decide which ones to keep or delete.  It may turn out that that image you wanted to delete was one that you will keep, or you may accidentally delete the wrong one, and you can easily undelete on your computer if that happens.
Title: Re: Never delete images 'in camera'
Post by: neuroanatomist on January 22, 2012, 02:32:31 PM
Is this true?

I just hate when people give incomplete advice.  Your friend was completely correct, but he forgot to tell you that advice only applies on Tuesdays when there's a new moon and you're standing outside on your left foot, facing due northwest at exactly 1:03am.  Any other time, you'll be fine.
Title: Re: Never delete images 'in camera'
Post by: CowGummy on January 22, 2012, 02:48:18 PM
Is this true?

I just hate when people give incomplete advice.  Your friend was completely correct, but he forgot to tell you that advice only applies on Tuesdays when there's a new moon and you're standing outside on your left foot, facing due northwest at exactly 1:03am.  Any other time, you'll be fine.

LOL!  ;D
Neuro, that cracked me up big time!
Title: Re: Never delete images 'in camera'
Post by: smirkypants on January 22, 2012, 03:02:50 PM
But! But! OMG! You could get a power surge and overload the circuitry!!! Don't forget to park the hard drive in the Compact Flash drive before you travel with it, too.
Title: Re: Never delete images 'in camera'
Post by: Kernuak on January 22, 2012, 03:04:25 PM
There is one school of thought that deleting in camera can sometimes increase the risk of card failure due to corruption. I suspect it was true of older cards, but I don't know about recent cards. I generally wait until I get home just in case, to avoid losing anything, but I couldn't even conceive of a way that the processor could be damaged  :P. I've never had a card fail (famous last words), but that doesn't mean to say that my practice of not deleting in camera has been the reason. I know of others who have had card failures and may be coincidentally or may be not, they have deleted in camera. I also know of people who delete in camera and haven't had a problem.
Title: Re: Never delete images 'in camera'
Post by: NormanBates on January 22, 2012, 03:12:58 PM
indeed, best practice is to never delete images from the card, period
store stuff into your card, low-level format card, store stuff into your card, low-level format card, etc: never delete anything

on flash memory, if you delete stuff, you have to reset the bits, otherwise it will take more time to write again, and corruption errors may arise; deleting images (in camera, or in computer) does not reset the bits; low-level format does

admittedly, this should be a very small issue, and I'd be surprised if you ran into any problems while shooting stills
for shooting video (where a single bit going the wrong way becomes clearly visible), it may be more problematic

but chances are, if you run into problems, it will be something else (it's much more likely that some usb ports in your computer, or the usb reader, or the card, have a problem)
Title: Re: Never delete images 'in camera'
Post by: smirkypants on January 22, 2012, 03:21:18 PM
Ok. I shoot a lot of sports. I fill 32gb cards and change  in a day. The LAST thing I want is to fill up my hard drive with a bunch of crap that I don't need to look at. When you're shooting lots of frames a second a certain number will be blurry, a certain number will be framed crappily and a certain number will have the ref wander into the way. I've made it a habit during pauses to clean up my card and quickly toss obviously crap shots. If in doubt I keep it, but the crap goes. I use Lexar 600x cards and I've never as much as had a hiccup.
Title: Re: Never delete images 'in camera'
Post by: awinphoto on January 22, 2012, 03:22:41 PM
From what my experience has been, when you delete photos in camera, while it should be fine, a) it doesn't fully remove the image, Part still remain hense you can use software to recover images if you accidentally delete something. B) if you wish to fully remove files, format the card in the computer. Formatting in camera does a good job but some traces may still remain. Lastly c) as far as damaging the CAMERA, balony. There could be a shot of getting corrupt files here or there, but camera will be fine.
Title: Re: Never delete images 'in camera'
Post by: michi on January 22, 2012, 03:28:25 PM
I have deleted pictures off my cards since my first digital camera 10+ years ago and still do all the time with my 7D and 5DII, never a problem.  Now if he said it might cause card problems, fine, may be he had a bad card and a bad experience.  But the processor?  That's just ridiculous.  How does reading or writing physically damage a processor?  (Technically, deleting is just writing on the card anyway, so it's the same as writing a picture onto the card.)  So next time he tells you this, just smile and say "ok, if you say so" and then go back to deleting the pictures of your cards in camera if that is what you like to do.
Title: Re: Never delete images 'in camera'
Post by: Kernuak on January 22, 2012, 03:43:30 PM
I imagine the key to possible card corruption is the format. If you delete in camera and never format, there is probably a risk, but if you delete in camera and then format when you get home, then in reality, there probably isn't alot of difference to not deleting in camera. Like many "facts" that are passed on, I think it may have been lost in translation.
Title: Re: Never delete images 'in camera'
Post by: neuroanatomist on January 22, 2012, 03:45:19 PM
Well, I suppose since it was the friend's camera, the friend's rules should apply, right?  Say...only press the shutter release with a chopstick...or, don't use Tv mode because that might blow up the sun.  My camera...my rules.  ::)
Title: Re: Never delete images 'in camera'
Post by: Tijn on January 22, 2012, 03:47:54 PM
New question then: when a picture is "deleted", usually it still remains in the card's memory somewhere - it's just not accessible through the regular filesystem, until it's being overwritten with something else. Add to this the complications of flash memory which tries to overwrite the same data space as little as possible (because there is a maximum durability of 'amount of times a bit can be overwritten' before it becomes unusable).

Regardless, is there a difference in recoverability deleting them in-camera or from your PC?

I've recovered images I'd deleted thought my computer from a card once, but when I tried that after deleting something in-camera and I couldn't find the files I deleted any more. Is there a difference?
Title: Re: Never delete images 'in camera'
Post by: Mappy on January 22, 2012, 04:11:10 PM
There is no difference in the deleting process of your pc or your camera (unless you shoot raw+jpg and only delete one on your pc ;)). When deleting on camera there is a higher chance that you will use the disk space for a new picture again, if you continue shooting before trying to undelete.

Next to the before mentioned "you can only see what you want to keep on a big screen", another reason why I always keep my pictures is to make sure my numbered archive is complete and I know I didn't lose a picture somewhere.
Title: Re: Never delete images 'in camera'
Post by: distant.star on January 22, 2012, 04:45:33 PM
Is this true?

I just hate when people give incomplete advice.  Your friend was completely correct, but he forgot to tell you that advice only applies on Tuesdays when there's a new moon and you're standing outside on your left foot, facing due northwest at exactly 1:03am.  Any other time, you'll be fine.


After consulting with my friends in the CHAP (Canon Heavenly Assurance Program) you'll have to update your conditions, Big Brain.

It seems that if those conditions DO exist, and the camera processor is at risk, everything is fine if Michael Culligan's "Due Northwest" is playing at the time (within earshot, of course). For those who want to be safe, here's a link to a performance:

http://www.youtube.com/watch?v=KsZDm0fKhdM
Title: Re: Never delete images 'in camera'
Post by: KevinP on January 22, 2012, 04:48:25 PM
As with everyone else here, I've never had any problem with deleting images in camera.  My problem is when I delete an image, or images, that I did not want to delete.  That happens more often than I'd like to admit.  It's easy enough to fix, just don't delete images in the camera.  Solve both "problems".
Title: Re: Never delete images 'in camera'
Post by: Positron on January 22, 2012, 04:55:50 PM
As for the processor - no way.

Solid state memory (such as CompactFlash) does have a limited number of writes per bit, but when you delete an image, it doesn't actually overwrite those bits, it simply deletes a pointer so that the data can no longer be accessed. It only overwrites that data when a new file is stored to the same physical location (which any competent solid state controller will only do after all other physical locations have been used, to keep the wear balanced), or when you low level format (all bits reset to 0). Even deleting everything from the card using an erase all images will only change pointers and be no different from clearing the card when it's attached to your computer.

More importantly, the lifespan of even the cheapest card is not a matter of concern right now, because by the time it dies from normal use, the card is likely to be obsolete due to increases in storage density. I've had a few cards die from use from way way back in my P&S days, and the largest one was 256MB.
Title: Re: Never delete images 'in camera'
Post by: unfocused on January 22, 2012, 05:42:48 PM
Okay, a related question.

I always assumed that it was best to format the card in-camera so that it is formatted to the camera's specs. I see some advising formatting on the computer. Kind of a moot point for me, frankly, since I don't even have a card reader, but, is there any difference?

Of course I'm talking formatting, not just deleting. I routinely format my card once I've uploaded the images and verified the files are okay.
Title: Re: Never delete images 'in camera'
Post by: TexPhoto on January 22, 2012, 05:48:54 PM
As the others have said, no you cannot hurt the processor.  But there is no real reason to delete and image.  It's actually not gone anyway, you could recover it.

For a long time I have dolled out the following advise in order to reduce the chance of corrupt file on a memory card:
1. Don't delete images in camera or on the computer.  Unless you are desperate need to make room. (but maybe buy a bigger card next time) Way bigger than you need is the size you want.
2. Transfer all the images to the computer, and then back them up, before you remove anything from the card.  At this point, feel free to prune away the good from the bad.
3. Format the card in camera, rather than delete anything.  That way the card is set up the way the camera wants, not the computer.

My system works for me and the people who I've given the advice too.  Before i did this, I'd have a corrupt file or whole card every few months.  Since then, 4 years, no problems, shooting 30K photo a year.  I think the problems I was having were related to going from camera to mac and sometimes PC.  Essentially giving 3 computers the chance to put their own peculiar files onto that little hard drive. 
Title: Re: Never delete images 'in camera'
Post by: wickidwombat on January 22, 2012, 06:20:39 PM
Got a shocked telling off from a friend of mine when I deleted an image I'd taken on his brand new 7D.  He told me it was possible to damage the processor by deleting images from the memory card 'in camera'. ONLY delete the images off the card when the card is being read on a computer, he told me. Never heard THAT before, and can't quite believe it. Is this true? If so, why? - and surely Canon wouldn't provide a 'delete' button!
ROFL :D great first post! got a good laugh from that, me thinks your friend suffers from a more than a little case of paranoia. In fact deleting in camera is much safer than deleting from the card on a computer. I am not sure if it happens with canons but with Nikon I had a strange problem where my wifes cards were showing all full in camera but they were blank when plugged into a computer. I worked out the problem was she had been deleting the images from the computer not from the camera or formating the card in camera. I think the problem is that the files dont actually get deleted this way unless you empty the trash as well. So now we just stick with clearing files in camera.
Title: Re: Never delete images 'in camera'
Post by: briansquibb on January 22, 2012, 06:29:31 PM
He could buy a 128Gb card and shoot in jpeg. When it fill he could just replace it with another 128gb card and keep the first as a backup copy

 ;) ;) ;)
Title: Re: Never delete images 'in camera'
Post by: distant.star on January 22, 2012, 06:32:36 PM

That's funny. Only need one card each year. Easy to buy for at Christmas!


He could buy a 128Gb card and shoot in jpeg. When it fill he could just replace it with another 128gb card and keep the first as a backup copy

 ;) ;) ;)
Title: Re: Never delete images 'in camera'
Post by: pwp on January 22, 2012, 07:05:33 PM
Everyone has their own way of doing things. I can edit/sort/rank/delete files way faster back in the studio on a 30 inch monitor than making those assessments while out on a shoot. On a shoot I'm more interested in locking into the project rather than doing "on the fly" edits.

Memory cards have been so inexpensive for years now; I just take more than I figure I'll ever need, a couple of 32 Gb and a few older 16Gb cards.

My workflow moved to this "no deletes" approach  a few years ago when I did a couple of accidental deletes, regretted mistakes made while under pressure. Also, occasionally a blurry out-take may make the perfect background for one of your hero shots.

An important part of your post production workflow is to become a ruthless editor. With practice it's not hard to pull a 1000 file shoot down to the sweet top 20, depending of course on your project and client requirements, but you get my point.

Deleting in camera is totally valid and important if you are shooting news or sports for a wire service and use the opportunity for editing-down during lulls or shorts breaks. This can mean vitally quicker image delivery of your most relevant images.

Paul Wright
Title: Re: Never delete images 'in camera'
Post by: Positron on January 22, 2012, 07:21:03 PM
Okay, a related question.

I always assumed that it was best to format the card in-camera so that it is formatted to the camera's specs. I see some advising formatting on the computer. Kind of a moot point for me, frankly, since I don't even have a card reader, but, is there any difference?

Of course I'm talking formatting, not just deleting. I routinely format my card once I've uploaded the images and verified the files are okay.

To be honest, I think all the popular card types use FAT32 as their filesystem now (I know there's been some push toward ext2 for microSD, but that's not really relevant to the question). I would recommend formatting in-camera only because certain cameras with certain firmware might only be designed to read/write one filesystem or another. I suspect on modern cameras that isn't much of an issue, but the point is that there is no way to format in camera and end up with a filesystem that the camera can't read, whereas it would be possible, formatting on the computer.

There's no actual way to "damage" the card by formatting it (other than normal wear from write cycles), but it's just guaranteed to work if you do it in the camera versus on the computer.

Finally, there's no need to reformat your card every time you dump images off it. Compared to just erasing all images, reformatting rebuilds the filesystem, which is unnecessary since a filesystem never "expires". The only times I'd bother reformatting is the first time you use a card, if you switch that card to primarily be used in another device, and of course if the camera is having trouble reading/writing the card. Otherwise you're just spending extra time and putting extra wear on the card for no real benefit.

Edit: As regards "the camera's specs", all major filesystems are standard, so the camera can't somehow "do something different" as regards the filesystem. The only reason that would ever happen is if the camera's manufacturer wanted to make it proprietary to force you to buy their cards (which would no longer actually be CF, SD, etc., even if they were the same shape), which none of the big manufacturers do.
Title: Re: Never delete images 'in camera'
Post by: distant.star on January 22, 2012, 08:27:59 PM

My workflow moved to this "no deletes" approach  a few years ago when I did a couple of accidental deletes, regretted mistakes made while under pressure. Also, occasionally a blurry out-take may make the perfect background for one of your hero shots.

Exactly! I thought that was one of my secrets!!

Title: Re: Never delete images 'in camera'
Post by: willrobb on January 22, 2012, 08:32:56 PM
Ha ha, maybe someone was tasking the mickey out of your friend and they took it as fact. The only problems I've ever known to happen by deleting in camera is when a friend accidently hit "erase all" after a day out taking pics....OUCH!
Title: Re: Never delete images 'in camera'
Post by: Drizzt321 on January 22, 2012, 09:30:13 PM
To be honest, I think all the popular card types use FAT32 as their filesystem now (I know there's been some push toward ext2 for microSD, but that's not really relevant to the question)

Actually, it's exFAT I believe, which is an Microsoft filesystem, designed for removable flash memory based drives for higher capacities and larger file sizes (e.g. >4GB video files). ext2 is a Linux filesystem, which is actually quite old. ext3 and now ext4 exist, which basically just extend ext2 and, generally, provide a degree of backwards compatibility with ext2.

Also, it's not the cards that use FAT32, it's the camera's that use FAT32. If the camera's start supporting exFAT, then I could use that instead (provided my computer can read exFAT, which all >=Win Vista can, not sure about OS X) and be fine.
Title: Re: Never delete images 'in camera'
Post by: PeterJ on January 23, 2012, 01:05:27 AM
I always assumed that it was best to format the card in-camera so that it is formatted to the camera's specs. I see some advising formatting on the computer. Kind of a moot point for me, frankly, since I don't even have a card reader, but, is there any difference?
I agree with this approach. While in the ideal world it wouldn't make any difference there are a lot of optional fields in FAT32 and some latitude to where things are stored on the card within the spec. One day Microsoft or Apple might decide to move something around in a perfectly valid way within the spec that Canon doesn't handle properly 100% of the time. I also think a format is better than a delete, once again this shouldn't happen but for example:

There's a part in FAT32 that hints where the next free cluster is likely to be, if you've been deleting as you go that may very well be right at the end of the card. The firmware should wrap back and start looking at the beginning. But does it work, has it ever been tested, maybe the code errantly wraps back to sector 0 and wipes out the volume information, who knows? Those are the sort of bugs that happen so rarely they can go undetected a long time.

I always think there's a lot to be said for starting from a known point each time which puts everything on the best tested code path. Having said that it's all unlikely to cause problems and no doubt some would do it for years without ever having a problem.
Title: Re: Never delete images 'in camera'
Post by: NotABunny on January 23, 2012, 03:25:04 AM
This problem may occur not only when images are deleted, but when images are written as well (there is no difference, you know).

I've heard that once the camera writes the image numbered 25673, the memory corruption gets so bad that from that moment on all the photographed people are recorded naked!!! :o

Also note that this is 2012, so at some point the memory corruption might get so bad that the world will really end (for that memory card, I mean). The best advice that I've heard is to not shoot with a memory card in the camera.
Title: Re: Never delete images 'in camera'
Post by: wockawocka on January 23, 2012, 04:00:47 AM
Got a shocked telling off from a friend of mine when I deleted an image I'd taken on his brand new 7D.  He told me it was possible to damage the processor by deleting images from the memory card 'in camera'. ONLY delete the images off the card when the card is being read on a computer, he told me. Never heard THAT before, and can't quite believe it. Is this true? If so, why? - and surely Canon wouldn't provide a 'delete' button!

Don't ever take advice from this person.
Title: Re: Never delete images 'in camera'
Post by: gonzalo on January 23, 2012, 05:17:43 AM
Is this true?

I just hate when people give incomplete advice.  Your friend was completely correct, but he forgot to tell you that advice only applies on Tuesdays when there's a new moon and you're standing outside on your left foot, facing due northwest at exactly 1:03am.  Any other time, you'll be fine.

JAJAJAJAJAJ, Great ¡¡¡
Title: Re: Never delete images 'in camera'
Post by: japhoto on January 23, 2012, 05:19:25 AM
I always assumed that it was best to format the card in-camera so that it is formatted to the camera's specs. I see some advising formatting on the computer. Kind of a moot point for me, frankly, since I don't even have a card reader, but, is there any difference?

There can be a difference between the two methods, via computer being more "thorough" format.

As crazy as this sounds, I had a problem with my old Olympus gear that got solved only when I formatted the card with a card reader. Hold the pitchforks on why I used Olympus.

I started out with the E-520 and had two 8Gb CF-cards to go with it. When I upgraded to the E-3, I did what probably most of us would do. I popped one of the cards in, formatted it in-camera and tested that it functioned right. The problem didn't show itself every time and it made me think that the body itself was faulty. It would work just as normal for a few shots and then it would freeze, mirror locked up and shut itself down. Battery had to be taken out to clear the camera and in a while it would do it again.

There was some talk on Oly forums about similar issues and the CF-card was thought to be one possibility for these problems. I formatted both my cards in the card reader (quick format didn't help either) and never had that problem again. And that's two years of carefree operation after that.

So yes, I think there's a difference between formatting in-camera or with a computer. To be on the safe side I usually format my cards in the computer from time to time and when I put them back in the camera I format them again in-camera. I also did this when I moved to Canon (since I still use the cards) and had 0 problems with this transition.
Title: Re: Never delete images 'in camera'
Post by: Ellen Schmidtee on January 23, 2012, 07:22:08 AM
I'm no expert, but as far as I know ...

Memory cards are optimized for sequential writing. After a format, the camera can write sequentially from start to end. When files are deleted, 'bubbles' of free space are created. When the camera records to those areas, it may be forced to write non-sequentially once the bubble is filled, taking a performance hit.

In SD cards, this is part of what makes the difference between the X rating and the class rating.

I've deleted files on Canon cameras (powershot A460, EOS 450D, EOS 600D, and an EOS 5D mark 2) for at least three years, and I've never CPU problems or card corruptions. The only time I had photos corrupted was due to a card reader which had intermittent problem - copying the file a 2nd time got an image with correct contents, proving the image on the card was not corrupted.
Title: Re: Never delete images 'in camera'
Post by: awinphoto on January 23, 2012, 10:33:31 AM
I always assumed that it was best to format the card in-camera so that it is formatted to the camera's specs. I see some advising formatting on the computer. Kind of a moot point for me, frankly, since I don't even have a card reader, but, is there any difference?

There can be a difference between the two methods, via computer being more "thorough" format.

exactly... I've heard people who say when you get drives for the first time, such as a backup hard drive, flash card, etc... that you should first format it in computer in case it has some manufacturer software/backup/whatever... but after that, in camera formatting on occasion (after transferring all the pictures you want onto your computer) should be fine.  In camera formatting is nice because it sets up the card the way the camera wants it, but then again, formatting in computer, once plugged back into the camera and you start taking pics, the camera automatically sets up the card anyways... Also consider the in camera formatting, on average, takes a matter of seconds... maybe 20-30 seconds if you have one of the bigger/slower cards on the market... whereas the computer can take hours, so it could say how thorough and destructive it is to old files.  I'm admittedly not as computer geeky to be able to explain why, but it is what it is. 
Title: Re: Never delete images 'in camera'
Post by: bycostello on January 23, 2012, 10:51:08 AM
I was told never to do it just in case you mistakenly do something stupid like delete wrong image or really crazy like format your card...
Title: Re: Never delete images 'in camera'
Post by: Maui5150 on January 23, 2012, 12:18:47 PM
I delete a ton of images "in camera" especially when I am starting a shoot and dialing my my light set-up.  If you know the image is junk, why keep it.

I think you are far more likely to "miss a moment" by having a full card than you are deleting an image you wanted.
Title: Re: Never delete images 'in camera'
Post by: iaind on January 26, 2012, 04:42:38 PM
Is this true?

I just hate when people give incomplete advice.  Your friend was completely correct, but he forgot to tell you that advice only applies on Tuesdays when there's a new moon and you're standing outside on your left foot, facing due northwest at exactly 1:03am.  Any other time, you'll be fine.

JAJAJAJAJAJ, Great ¡¡¡

If you are standing under a waterfall and attempting to change lenses simultaneously the camera may fail.
Deleting the image is to blame not water ingress.  ;) ;) ;)