Long Exposures, what's wrong here? Pretty big dip in quality

When I figured out how to take long exposures with an old Lumix P&S, I fell in love with digital photography. Wasn't until later when I had access to an old Rebel DSLR that I tried it again, and rekindled that love when I bought my 1D. It took me long enough, but I figured out how to work around the noise problems with the 1D by turning down the ISO and so this past month I've been taking a few long exposures every weekend.

Right off the bat, I spotted something off with my images. They seem to get really blotchy and seem to lose a lot of details when taking a longer exposure past maybe 3s? Something seemed off, like say for example a concrete path will seem to lose depth and detail..

Could I get some critiques? And some help understanding why it seems like quality doesn't look too great?

Took this with a 28mm 1.8 @ 2.8 for about 10s @ iso-200?

(there's dust on my sensor! )

Well, in the first shot you're shooting at f/2.8. That means a narrower depth of field then you can get with a smaller aperture. Since you are already shooting off a tripod, I suggest going to f/8-f12 ish and see how that works out.

Agreed..

Start at F8-F11 and use the Highest ISO and SS to get it exposed properly.. then once you get your #'s Use you math skills and figure it out what the Exp should be at ISO 100... Do not be scared of leaving that shutter to bake for a good minute or 2..

Also keep in mind that even a light wind can affect sharpness on long exposures. Make sure if you have a neck strap attached to your camera that it's not moving at all during the shot. I see the flag in your third shot is standing out pretty straight like there may have been a ~15MPH wind.

The last two shots are suffering from flare and/or other reflections caused by the bright lights in the frame...these effects can wash out parts of an image, reduce contrast, and lose depth as well. You probably had a UV filter on the lens too which compounds the problem...if so, remove it when shooting with bright light sources.

#1 looks sharp
the rest dont so there is camera shake, you dont need much.

And I have found that IS can mess up long exposure too. Turn it off. Though you have not used this type of kit.

Your camera's age is irrelevant. It's sensor just restricts how big you can blow a perfect image up.

As to detail being lost, if the detail is picked out by shadows being cast, if there are moving light sources in the area (such as cars) then those shadows will get washed away by these light sources.

Internal reflection at long exposures are a consideration to, so dump the protective filter during these exposures. And light leak from the viewfinder can also occur.

In the places where these were shot, there are multiple temperatures of light. This will cause part of your picture to be bathed in warm, yellow light and other areas to be lit by cool blue.

ItsMike wrote in post #14019816
Agreed..

Start at F8-F11 and use the Highest ISO and SS to get it exposed properly.. then once you get your #'s Use you math skills and figure it out what the Exp should be at ISO 100... Do not be scared of leaving that shutter to bake for a good minute or 2..

I tried that last night, a high aperture and slow shutter speed but the photos were ruined by noise

You were getting excessive noise at ISO 100?

ItsMike wrote in post #14022671
You were getting excessive noise at ISO 100?

Actually no, I was getting excessive noise at 400. I'm sure if I tried 800 or above the picture would've been worse.

you need a more defined focal point the eye moves too much

My 60D and XTi have "Long Exposure Noise Reduction" - with this turned on in the menu, the camera takes two exposures, one with the shutter open and another with the shutter closed (or mirror up? dunno) for the same settings. It then compares the two exposures, and uses the noise present in the non-exposure to eliminate the noise in the real exposure. It makes each shot take twice as long, though.

Make sure this feature is turned on and your long exposure noise should all but vanish.

nathancarter wrote in post #14039719
My 60D and XTi have "Long Exposure Noise Reduction" - with this turned on in the menu, the camera takes two exposures, one with the shutter open and another with the shutter closed (or mirror up? dunno) for the same settings. It then compares the two exposures, and uses the noise present in the non-exposure to eliminate the noise in the real exposure. It makes each shot take twice as long, though.

Make sure this feature is turned on and your long exposure noise should all but vanish.

Yep, I wondered why it never seemed to work well. Then I turned it on, took a 20s exposure and saw the difference

Beware if you shoot on a bridge, these structures move slightly. Especially with moving traffic or wind. You might not notice it, but even light shaking will cause a visible effect on your images.

john5189 wrote in post #14020453
And light leak from the viewfinder can also occur.

Is this possible even if the mirror is locked up during the actual shoot? I thought it only affected metering before shooting, if the camera was away from the eye.

nathancarter wrote in post #14039719
My 60D and XTi have "Long Exposure Noise Reduction" - with this turned on in the menu, the camera takes two exposures, one with the shutter open and another with the shutter closed (or mirror up? dunno) for the same settings. It then compares the two exposures, and uses the noise present in the non-exposure to eliminate the noise in the real exposure. It makes each shot take twice as long, though.

Make sure this feature is turned on and your long exposure noise should all but vanish.

Are you certain of this? I think it only adjusts the Noise Reduction processing carried out by the processor, not take another picture and compare.

As per the 550D/ T2i manual when you set this to 'On'

Hmm not exactly clear what it means by 'noise reduction process' exactly...