S 110 Pictures too dark...

[Ken Nielsen]

When taking pictures at night of a city scape the resulting pictures look even darker than the scene appeared to me in real life. I thought the metering system normally would try to compensate exposure time to gather enough light to approximate a normal shot as viewed by the human eye. The camera does fine on indoor shots without flash with a tripod, but the outdoor shots of a city scape at night shots look way too dark.

How would a professional handle this? What settings do I need to work with when trying these shots again?

[dtrayers]

Unfortunately, the S110 has a longest shutter speed of 1 second. Night scenes typically require up to 15 seconds. Later versions of the Powershots have a 'long shutter' mode where you can set the shutter speed up to 15 seconds. They won't meter in long shutter mode, so it's a little trial and error with the histogram, but it's workable.

The best you can do is boost the ISO to 400, then the image will be pretty grainy.

If you're adventuresome and are handy in Photoshop (or other editing software that uses layers), you could try taking several shots at the longest shutter speed and stacking the images in the computer. I think using the screen or overlay blending mode and adjusting the opacity might lend good results. I've never tried it. You'd have to make sure the camera didn't move between exposures so the images line up.

[Ken Nielsen]

Thanks for the facts, even though I wish they were not. A longer exposure time in manual mode just makes sense to have.

The 'Multiply' mode in Photoshop is the equivalent of stacking transparencies together. I'll play with it.

ISO 400 eh?

Any other ways to hold the shutter open for longer?


8 minutes at f/8 used to work good at 150 ISO for moonless out in the woods shots at night.

[dtrayers]

Thanks for the facts, even though I wish they were not. A longer exposure time in manual mode just makes sense to have.

The 'Multiply' mode in Photoshop is the equivalent of stacking transparencies together. I'll play with it.

ISO 400 eh?

Any other ways to hold the shutter open for longer?


8 minutes at f/8 used to work good at 150 ISO for moonless out in the woods shots at night.

The longest shutter speed I've seen on any digicam is 15 seconds. If you want longer (like 8 minutes) you need a DSLR and BULB mode.

[Ken Nielsen]

I'll explore placing the camera under video x-ray while drilling with a 1/128" bit into the shutter chamber and inserting a fine wire so I can 'lock' the shutter open manually when I need a longer exposure. I like the smaller size of the Canon 110 so modifying the camera is not out of the question.

I'll let you know if I actually find a solution.

[Ken Nielsen]

I just found this, which explains why these cameras have limited exposure lengths:


Achieving Long Exposure Times

Sometimes, it is desirable to take an excessively long exposure in order to achieve the appropriate lighting effect.Â* In these cases, digital cameras have been unacceptable because of the accumulation of thermal noise eating the dynamic range until it can no longer take useful image data. Â* However, in concert with a computer, you can extend the dynamic range of a digital camera.Â* To do so, one can take multiple exposures in sequence and simply add them together within the computer.Â* In order for this to work, It is necessary that the raw sensor data be available to the host computer. Otherwise the mathematics of this process will not be correct.


Â*Blooming

There are some special artifacts that are present in digital cameras that are not found (or are differently manifested) in conventional film photography.Â* The most noticeable is Blooming.Â* Blooming occurs when a pixel receives too much lightÂ* In these cases, the "bucket" can be considered to literally overflow.Â* What happens to the extra electrons is what is important.Â* in well designed cameras, the overflow is properly siphoned off without affecting neighboring pixels.Â* In less well designed systems, the extra charge is allowed to spill into neighboring pixels thereby spreading the size of the highlight.Â* If the spread is non uniform, as is typically found in a scanning camera, then the artifact can be quite disturbing since it appears as an unnatural stripe in the image.

In photography one can typically find specular highlights that are several f-stops brighter than the rest of the image. Â* For this reason, the effect of blooming is important to quantify for a specific camera."

[dtrayers]

Yes, DSLRs do a better job handling the blooming and dark current effects.

Here's a post I made when I had a Digital Rebel and made a 16 minute exposure:

http://photography-on-the.net/forum/showthread.php?t=29035

A pretty good discussion followed.

[Ken Nielsen]

I'm wondering why you would have to take several shots, using the Photoshop method, when you could just stack one shot, duplicated over several layers, and then apply the modify to that?

[Jon]

If you use multiple shots the presumption is that they won't have identical blooming in any given cell over the various exposures, thus averaging out the noise.

[Ken Nielsen]

Yes, You did a "16 minutes at f/11 and 200 ISO."

I have been playing with this in PS CS and using multiple shots taken at the same location in order. I am not getting an acceptable result (although I can now see how this works - I can also get the same results using the histogram) using screen blending mode (or any of the other modes) because the shadows have no detail in the first place - which all adds up to noise when I add layers and blend in PS CS.

I think this means I need a different camera.

What camera do you recommend that I get in order to be able to capture image in low-lit shadows? The view looked beautiful with the naked eye, but the little SD 110 has dropped all of the shadow detail to black.

I want the smallest size camera available that will still do the capture and 'bulb' time exposure.

-or-

I used to have a Nikon EM, film camera that would measure and correctly expose for up to 8 hours. Maybe I should just go back to that type of equipment for the night shots?

[dtrayers]

Yes, You did a "16 minutes at f/11 and 200 ISO."



What camera do you recommend that I get in order to be able to capture image in low-lit shadows? The view looked beautiful with the naked eye, but the little SD 110 has dropped all of the shadow detail to black.

I want the smallest size camera available that will still do the capture and 'bulb' time exposure.


Which is the same as 15 seconds at f/2 @ISO 400. And if you shoot in RAW mode you might be able to under expose (ISO 100) and still pull out shadow detail.

If you don't want an SLR but still want bulb mode there are only two that come to mind: the Minolta A2 and the Nikon 5700, both almost as expensive as the Digital Rebel.

I wouldn't like to see the noise from the Minolta or Nikon at such long exposures, though.

If you want to try stacking some more here's an article about it:

http://www.astropix.com/HTML/J_DIGIT/TOC_DIG.HTM

It's targeted towards astrophotgraphy but it still applies.

[Ken Nielsen]

Great article. The fact still remains. If you want detail in dark situations, turn on the double oven timer.

: )


Sincere Thanks,

Ken

[Ken Nielsen]

Don't you love it when you find out you have something you didn't think you had. Fact of the matter is, the SD 110 has an array of choices for shutter in manual mode from 1 sec. on up to 15 sec. This makes the camera entirely useable over many situations that I wanted to work in, one of which is low light night photography in the city. With up to 15 seconds of exposure time at my disposal, I should be able to keep the ISO rather low and still get the shots I want, mainly architecture, and preserve the quality needed to get decent looking shots.

I am the happiest guy in North America when I got out the manual and discovered this.

Thanks to all for the low lighting scenarios and information, all of which is useful.

My apologies for saying I had the S 110 when I actually have the SD 110. The specs for the S 110 are as you had quoted me here: "Flexible Operation - The S110 boasts the fastest shutter speed in its class with 1/1500 second. Or, take beautiful low-light shots with slow shutter speeds as long as 1 second."

That little 'D' made quite a difference.

Thanks Again to all,

Ken

[Ken Nielsen]

On the SD 110, I have been experimenting with shooting in 'Long Shutter' mode with shutter speeds up to 15 seconds. While I am now getting a better 'gathering' of light, I notice that even with superfine (highest resolution) selected, and with longer exposures, the camera electronics seem to be doing something to degrade the resolution as the resultant images are definitely not 'superfine.' Is this normal?

Also, Adjusting Exposure Compensation: Is this a facsimile of aperture setting? Do these cameras have a physical mechanical aperture? shutter? Using this setting seems to adjust lightness and darkness but does not seem to work in conjunction with Long Shutter mode. Should it?

Just trying to learn the camera here,

TIA,

Ken

[Ken Nielsen]

Aperture is always mechanical, or so I have heard. Shutter can be mechanical up to 1/500th of a second and even higher with CCD shutter at 1/1600 sec.

I think the degrading of images I am shooting with extended exposure times is the result of a noise reduction routine built into the camera.

"Effectively canceling out the digital noise is NOT what a dark frame subtraction does. DFS just tries to cancel out heated or dead pixels on the exposure. It doesnt battle random or pattern noise generated by the CCD.

Most digicams and DSLRs have a noise reduction routine in its imaging chip to deal with digital noise, apart from the DFS used for longer exposures."

I'm posting to myself here, but maybe some of this information will be useful to others working with a digicam.