Is my Canon T1i faulty? red, green, blue dots on full size image

[anthonyjstewart]

Hi all. I took some pictures last night of a major fire near our building. The pictures cam out pretty well, it all happened so fast. I used a tripod and was happy with the results until I clicked 100%.

I used to have a 5D2 for 9 months before I traded down due to size and I have been quite disappointed with the T1i in comparison. It's just back from the repair shop too after dying at my sister in laws gradulation so I am wondering if I have a lemon.

Check out this photo attached and blow it up to 100% on your monitor and you will see what I mean.



Note the image speckles also showed up on the RAW version.

[inkista]

How long was the exposure? Hot pixels are a known phenomena with longer exposures.

Could be bad/stuck pixels, though, if the sensor's bad.

I would also state that expecting an entry-level crop sensor to have equivalent high-iso noise performance to a full-frame sensor is...er... wildly optimistic.

[aglio]

what ISO did you shoot that picture at?

[Doug Pardee]

Originally Posted by anthonyjstewart

I used to have a 5D2 for 9 months before I traded down due to size and I have been quite disappointed with the T1i in comparison.

You went from one of Canon's finest full-frame DSLRs to one of its entry-level APS-C DSLRs. I don't know how you couldn't be disappointed.

Note the image speckles also showed up on the RAW version.

Which Raw converter did you use? Adobe Camera Raw in Photoshop or Lightroom will automatically remove hot pixels, as will DxO. I've heard that Capture One and SilkyPix do, too. Bibble provides an option (under Sensor Correction).

Also, did you have Long Exposure Noise Reduction (Custom Function II-4) enabled? That would automatically have taken a black-frame shot after taking the real shot, then subtracted the noise out. (Manual page 185.)

[anthonyjstewart]

Well it still has the 50D sensor in it though so it should be up to the job. I am just surprised that's all as it shouldn't be there whether or not it's an entry level camera or not it is still an $800 camera.

ISO was 100 exposure was 35 seconds. I did it very quickly via picasa but I have never had this problem before even with RAW files.

Cheers

[anthonyjstewart]

On doing the research in the keywords above this is apprantly a common occurence although I have to say I never saw this once with the 5D2. And I took a stop motion video involving 3000 overnight shots some with as long exposure.

I DO think you should expect a sensor and a camera to cope with this if it designed to take pictures at long exposures and especially if the body alone costs $799 whether considered entry level or not. I will be sending this back to canon for a replacement or repair. However, my understanding is it's quite common and is probably not likely to be repaired with a replacement. It is particularly prevalent at long exposures.

[anthonyjstewart]

Originally Posted by Doug Pardee

You went from one of Canon's finest full-frame DSLRs to one of its entry-level APS-C DSLRs. I don't know how you couldn't be disappointed.

Which Raw converter did you use? Adobe Camera Raw in Photoshop or Lightroom will automatically remove hot pixels, as will DxO. I've heard that Capture One and SilkyPix do, too. Bibble provides an option (under Sensor Correction).

Also, did you have Long Exposure Noise Reduction (Custom Function II-4) enabled? That would automatically have taken a black-frame shot after taking the real shot, then subtracted the noise out. (Manual page 185.)

Perhaps that is why I never noticed it before Doug, I always used photoshop previously but I just moved from a PC to a Mac and haven't installed photoshop yet. will check that tip out.

[skyline photo]

Too many pixels on a small sensor makes for a noisy camera. Thats the problem they had with the 50d. I had one for about 2 weeks and got rid of it for the mkii. Best move i ever made. Get back the 5d its quite superior. Sorry

[anthonyjstewart]

I fear I may be going in that direction.

[inkista]

Nope. You're going to have to pay three times as much and get a D3x and swap out all your lenses for Nikon. Even the 5DMkII exhibits this behavior.

Jeebus, guys, get a grip. Noise isn't the end of the world and you get what you pay for. No camera is perfect. Just learn dark frame subtraction or use the in-camera long exposure noise reduction and/or digital pull-processing. Sheesh.