jpeg images won't transfer

greenspun.com : LUSENET : Imaging Resource Discussion : One Thread

my 990 sometimes downloads with cf card reader all images; at other times i get the message "could not open jpg because a jpeg marker segment lenth is too short (the file may be truncated or incomplete). On the camera the images scroll just fine and there is no indicaiton of a problem. I tried using the cable and the problem arises there also. Sometimes the card is just fine and i get all the images; at others just a few. This happens with two cards (sandisk 30/64). I would appreciate any thoughts as I am getting very frustrated and can't find any information about this in the nikon 990 literature. thank you.

-- ibever (ibever@aol.com), August 21, 2000

Answers

I don't know if this will help, but try it. Reformat the card(s) in the camera. When transferring images, only use Window's Explorer program(I'm assuming you use Windows) to copy them off the card. Do not view them from the card with an editor, viewer, etc. Once you've transferred the files, do not delete them from the card with the reader, only delete them in the camera.

I'm not sure if this'll help, but I had similar problems with smartmedia cards when used with a reader. I found the above solved the problem. It seemed that deleting files, or sometimes just viewing them with a viewer like ACDSee, while stored on the card, messed up the file structure on the card in some manner and caused problems. Letting the camera make all the changes to the file structure seemed to solve the problem. I'm guessing that the cameras treat the cards a bit differently than the card readers, or vice versa. It's probably a really nitpicky little bug that no one who can really solve has stumbled across yet.

If what I described helps, you might consider informing both Nikon and the card reader manufacturer. Maybe it'd lead to a real fix. Maybe it's a Window's problem? Who can say?

-- Gerald M. Payne (gmp@surferz.net), August 21, 2000.


I finally called Nikon who answered quickly and suggested the following sources: 1) batteries 2) formatting problems --not done enough 3) camera goes off while downloading 4) shutting off camera while its loading a photo Since I've had difficulties with both my 950 and 990 on my imac, and don't download to the computer but via cf reader i am exploring the batteries. i have an olympus charger and perhaps it is not working. the technician believes that the camera may show images when taken with a low battery, but won't have enough juice to get them fully onto the card to download into a computer. Does this make sense?? I'm off to try out new batteries and see whether I have misjudged the battery life or the charger i use is defective. i'll check back if this solves the problem. thanks for thoughts and res

-- ibever (Ibever@aol.com), August 21, 2000.

I doubt the batteries are an issue. If there's enough power to record the images to CF so they can be viewed in camera, then they're stored... Thats, that! If there is a low power issue it should be handled by a brownout circuit in the camera which disallows operation below a certain point and shuts the camera down before it will no longer function correctly. That's standard microcontroller design, or should be!

As long as the engineering staff was conservative enough in setting the brownout voltage it shouldn't be a problem. I only have Toshiba's, but it's been my experience that they're conservative enough that the camera will shut down -and after a brief period the batteries might bounce back enough that a few more images might be possible. Although, I usually swap 'em out as soon as the camera indicates they're caput by shutting itself down...

As far as formatting goes, you shouldn't need to reformat unless the file structure gets screwed up on the card. That shouldn't happen in the course of normally transfering images on and off the card.

However, I do recall seeing somebody mention that they had similar problems with a Nikon, and found that they were shutting the camera off before the viewfinder light returned to normal(off?) when saving images... I confess to being a bit puzzled by that, as any properly written firmware should finish saving the image or whatever else it's doing before powering the camera down. It's not as though you're actually interrupting the power with the switch. You're just informing a processor that it can shut the camera down via it's own powerdown circuitry, be it an ultra low current sleep mode or what have you.

[I wander off into the darkness shaking my head and mumbling to myself... Again!] ;-)

-- Gerald M. Payne (gmp@surferz.net), August 21, 2000.


Moderation questions? read the FAQ