Sony Alpha 300 and long exposures

[ecotec]

Hello everyone,

I recently purchased the Sony Alpha 300 D-SLR. I have been pleased thus far, but have noticed something when I decided to start playing around with long exposures. It seems that I may have a 'dead pixel' or something of the nature. So I did some experiments and here is what I came up with.

With lens cap on: 30 second exposure with a low f/stop and 'Long EXP NR' turned on - results in a completely black image - as it should

With lens cap on: 30 second exposure with low f/stop and 'Long EXP NR' turned off - results in a completely black image, except one white pixel in the upper right corner! One stinking pixel, but I can see it.

This pixel appears only on exposures longer then 10 seconds, with Long EXP NR turned off and when the camera saves to JPEG. If I save to RAW, and repeat the above experiement, the white pixel does not show.

Has anyone ever seen this before?

Best,
Brandon

[Anbesol]

you already know what you have, a dead pixel. Its not a big deal at all, but you may want to contact sony to see if a single dead pixel is covered under warranty. You are losing only 1 pixel out of 10 million, it wont effect the results but may be a minor nuisance. I had a similar "problem", but quickly found out the ultra white spot was a light in a very distant small airport.

[ecotec]

Thanks for the reply. Problem solved. After a quick call to Sony to troubleshoot I simply went back to the retailer and exchanged the camera for a new one. The interesting thing is how Sony tried to troubleshoot the issue.

After dialing their 800 number I was speaking with a customer support rep in under one minute. Props to Sony. However, once I had explained the issue, the rep thought it might do some good to clean the photo sensor (with a blower). I informed the rep that I was fully capable of following the instructions in the manual, but he insisted he walk me through the cleaning process.

The rep failed to follow the process in the manual, which explicitly states to not attempt to clean the photo sensor if the battery is below a 75 percent charge, or risk potential damage to the shutter. Luckily no damage occurred, and I am sure that the 75 percent rule is quite conservative. But I must point out that I was misinformed on the proper cleaning process.

To make a long story short, I have a new camera, with no dead pixels, and remain impressed with Sony customer service.

Best,
Brandon

[Anbesol]

that is bizarre that you cant clean it when the battery is under 75%. I wonder why it sais that. Anyway - good deal on your situation.

[ecotec]

I assume they state 75 percent just to be safe. In cleaning mode, something inside the camera (maybe the photo sensor) vibrates, then the shutter opens and remains open. I would guess they want to safeguard against the battery dying and the shutter closing on the tip of the blower.

[pisco]

This is totally normal and it happens in all cameras. I think that their name is "hot pixels". Supposedly the Alphas at the end of the month evaluate the hot / dead pixels, re maps them and fixes them although I had no luck with this (you can manually change the date in the camera and it should work).
In my case Sony did fix it (I had about 50 hot pixels 8 months camera, about 3,000 pictures taken), camera came back with a clean sensor, no hot pixels, clean camera, etc and it was covered under warranty (Precision Camera did an excellent job). But after 8 months I'm having a few more (so I don't think that my camera is re mapping them properly - hence I start saying "supposedly").
Anyways, it is normal to fix this hotpix in photoshop for long exposures, I'm my case, my camera is probably still under warranty (if you pay with amex, it extends it an extra year), but I won't send it again.

I'm really impressed that Sony replaced your camera... anyways, I am sure that you will get new hot pixels, don't worry about them. It's not a camera defect.

[ecotec]

Thank you for the info. I had not encountered anything in the manual that matches what you described. The closest I found was the pixel mapping feature the eliminates hot pixels on the LCD. The manual says that even if spots appear on the LCD in live view, they will not show up on the photos...so pixel mapping is really to please the eye when shooting with live view. If I see this kind of thing pop up again, I will be sure to change the date on the camera and see if it fixes itself, that would be really nice if it could. Thank you again.

Brandon