Odd camera shake issue with 30d and sigma 24-70.

[benneh]

Basically as the thread title suggests I have a weird problem with camera shake, and I'm trying to figure out whether I have a hardware problem or not.

During a couple of recent shoots I've notices a strange camera shake on the lower half of some of my images. This happens regardless of shutter speed (examples shown below with high shutter speeds, which should totally freeze anything in the frame).

It's possible that I'm shaking a little when I shoot (and the images look as though the camera is rotating at the center or something), but I have a steady hand and I've gotten to the point where I can shoot with pretty low shutter speeds when needed, and regularly shoot hand-held HDR no problem. And at 1/8000 and 1/2500 I really don't see it being actual camera shake myself, I certainly wasn't rotating the camera whilst shooting.

All of this is visible in-camera btw (not through the viewfinder!), straight after taking the images in preview, on the LCD. It's not a raw conversion/lightroom/PC issue. I shoot in RAW, with a 30d purchased from a TP member, with the latest firmware 1.0.5. It's hard to say how many shots it's on, but it seemed to be on about 12k when I bought it, and I've added about 4-8k.

Here's some images and crops as example. Excuse the images .

1) - 1/1250, f3.2, iso 250

Crop)

2) - 1/8000, f5.0, iso 250

Crop)

3) - 1/2000, f2.8, iso 250

Crop)

Any opinions would be great before I end up sending the body for testing and returning the lens lol . I do seem to get a lot of Chromatic Aberration too.

 

[CT]

Very odd! The only explanation I can think of is that your shutter is faltering and only picking up true speed after it's started to travel. As the shutter in your camera travels vertically and upwards it would be logical for that to be the cause, but I'd certainly be getting it checked out.

 

[walls]

only thng to do is to stick it on a tripod and see if you can't reproduce the problem

 

[2blue4u]

Is this all with the one lens?

That appears to be two distinct images on the lower part of the shot - rather than a blurred single image. Has the lens taken a knock lately?

 

[benneh]

Is this all with the one lens?

That appears to be two distinct images on the lower part of the shot - rather than a blurred single image. Has the lens taken a knock lately?

This is what I was thinking/hoping. The images seem so distinct..
The lens hasn't had any knocks, and it's less than 3 weeks old. But tbh I'm less than impressed with it, seems a little soft and as I said above the Chromatic Aberration is quite an issue sometimes.

How could a lens produce an image like that though?, just bad refraction? (sp).


As for the tripod suggestion. I've also had this problem with 3 tripod images. Though tbh, at 1/8000 is shouldn't matter whether it was on a tripod or being spun around in a tumble drier .

And lastly.. Yep CT, that's a possibility too. Though I'm hoping it's not the shutter, as I only just bought the camera from a member here and it's just out of warranty , so that would suck.

 

[Hoodi]

Try a different lens! If you only have the 24-70 then badger local togs' here on TP, there's lots in Liverpool.

I wouldn't send anything to be looked at by anyone till you've ascertained whether it's the body or the lens. Do that, then take it from there.

 

[Gofer]

Well I'm certainly no expert but looking at the pictures closely the faulty lens scenario would seem to be the most likely. There are definitely two distinct images in the lower portion of the pictures rather than the blur usually attributed to camera shake.

 

[oldgit]

Try it on a tripod.

If you dont have tripod stand it on a flat steady suface (ie a wall) and focus on something then use the timer to take a shot.

Any shake then is in the cam or the lens

 

[inophoto]

Could the mirror be out of alignment? :shrug:

 

[pxl8]

It looks like something is shfting position during the shuter action. It could be a loose part in the lens or body but as the results are fairly constant I would say the body is more likely to be the culprit.

Pop into your local camera shop and ask if you can test a lens to rule out the body, and then test your lens on a different body. That will at least tell you what compenent is causing the problem.

 

[2blue4u]

2/5 lens
6/4 body
20/1 operator malfunction

 

[benneh]

I'm going to shoot with a 50mm f1.8 for a few days and see how that works out. But tbh it's going to be very difficult to replicate the fault, because it doesn't happen all that often. And there seems to be no pattern. So it's just a matter of shoot constantly.

 

[Jonnyreb]

Any shake then is in the cam or the lens

Or earthquake

Sigma have had a poor QC reputation in the past which they had seemed to have improved upon. I'd be tempted to rule out the question of the camera issue by testing with another lens first, then prepare yourself for returning the lens...........

You're lucky you bought the camera from a TPF member - perhaps they can help you out with some shots they took around the 14k actuation mark to assist you in ruling out the camera :shrug: