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09/22/2005 06:33:04 AM · #1 |
I've been using a couple of normal lightbulbs to light a still-life scene. But you get surprisingly little useful light for photography from these types of low-wattage bulbs.
So what I have been doing is opening aperture and increasing shutter speed to compensate, to 1/4 and 1/2 second. I am not using any kind of speedlight for this experiment, just the two bulbs.
What I've found is that no matter how precisely I focus (even using manual focus) I just can't get a good sharp shot, and I've bracketed most of the shutter speed / aperture combinations.
So, my question is; Would a brighter light source and the associated faster shutter speeds improve sharpness?
Probably sounds obvious, but I kept thinking there was something wrong with my focussing, until I began suspecting lack of light to be the issue!
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09/22/2005 07:34:43 AM · #2 |
you don't mention using a tripod ..
if you are not - you MUST at those speeds
i would suggest not closing down the aperture (thus making your DOF as wideas possible ) and increasing the time to compensate ..
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09/22/2005 07:40:20 AM · #3 |
Originally posted by ralphnev:
you don't mention using a tripod ..
if you are not - you MUST at those speeds
i would suggest not closing down the aperture (thus making your DOF as wideas possible ) and increasing the time to compensate .. |
I should have mentioned. I am using a tripod. And I use the timer (I don't have a shutter release) to make sure there's no shake when I press the shutter.
I ran out of time last night to finish this, but tonight I'm going to use the on-camera flash (ugh) and try a faster shutter to see if this makes the shot sharper.
There's nothing wrong with the camera btw. Normal outdoor shots in daylight with auto-focus are very sharp and clear. I just suspect that low-light + slow-shutter = lack-of-sharpness |
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09/22/2005 07:44:22 AM · #4 |
your camera has that swile design, do you think that that is causing it to be unstable on the tripod? I would imagine that even a tiny residual shaking in the grip could cause softness.
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09/22/2005 07:55:23 AM · #5 |
sorry - i haddn't noticed which camera you were using
i had a 990 a few years ago - & the silly thing would hunt for focus
just prior to fire even on timer - you have to be sure that you have a good contrast spot in your focus area (horz or vert in center, horz lines on the right &left, vert lines across top and bottom ) |
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09/22/2005 07:59:42 AM · #6 |
That seems odd to me that you are getting shutter speeds of 1/2 a second or longer. When I shoot still life, I set up this little box out of stuff from home depot out of PVC and a cheap white bed sheet and I use white poster board as the bottom/backdrop and I illuminate with two 100 watt household lightbulbs...and I have no problem at all hand-holding ... I get shutter speeds of 1/60 second or there about which is perfectly fine to hand hold up to 60mm or so (for me anyway).
But either way, I feel using a tripod severely limites my creative ability in just about all situations...so any time I have the choice of adding more light, or using a tripod, I'll be adding the light...or adjusting the ISO or opening up the aperture. A tripod is a last resort for me.
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09/22/2005 08:20:56 AM · #7 |
Thanks for all the replies - It's given me a few things to try out when I get home. I'll let you know if it works.
Originally posted by deapee:
That seems odd to me that you are getting shutter speeds of 1/2 a second or longer. When I shoot still life, I set up this little box out of stuff from home depot out of PVC and a cheap white bed sheet and I use white poster board as the bottom/backdrop and I illuminate with two 100 watt household lightbulbs...and I have no problem at all hand-holding ... |
Yea, that's the sort of setup I'm aiming for.
And I think I need to get 100 watt bulbs. I was actually using 40 watt bulbs, which might help explain the 1/2 second shutter speed. :-/
And sheets of white paper as reflectors - Though 40 watts doesn't give that much light to reflect! |
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09/22/2005 09:01:29 AM · #8 |
John,
It's funny that you posted this thread today I spent several hours doing a lighting study yesterday with my Mavica because as you stated low light situations even when I have the focus locked seem to result in a slightly out of focus image. Here's my three tries from yesterday I was using a Smith Vector single fill lamp bounced off a white reflector with a 250W bulb in addition to natural light from a window to the left of frame. You can view the app settings on the individual photos these are straight out of the camera with no editing whatsoever other than size reduction:
  
I have done some research into this mainly because of how many of my images in low light situations get declined by the stock co's I submit to even ones in perfect lighting situations sometimes have excessive noise.
From my many hours of reading on this subject I have learned that digicams (which I believe both our camera's fall into this category not a dSLR) sensors are extremely sensative to light and do a poor job of filtering and reading the different w/b even when set correctly you may end up with either noise or the dreaded purple fringe (which I also get) however the noise does clean up fairly easily in post editing. I have not had too many images rejected that were cleaned up with Neat Image.
I haven't tried a light box as deapee suggested yet but that will be next. Please let me know if you have any success in eliminating noise.
Regards, Michele
Message edited by author 2005-09-22 09:06:23.
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09/22/2005 09:34:03 AM · #9 |
With a wide aperture the DOF is very narrow so focus has to be precisely on what you want it to be on.
Low light makes it hard for any camera to AF correctly. Some have assist beams, but I still find that not very helpful.
I have the same issues with my Rebel in low light. If there is more DOF it is not nearly as noticeable.
When i was using hot lights and my Fuji S602 I could throw 2,000 watts of halogen on the subject from 18" away and still need 1/30 or longer shutter speeds.
IF you use flash, DO NOT mix the incandescent in there UNLESS you put a gel on the flash to make it the same color (temperature) as the hot lights. There is no way to WB the two different color temps, but using a gray card and adjusting in PS after should get you close.
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09/22/2005 08:13:02 PM · #10 |
Okay, I'm back and I've finished my testing. The results of which will astound and amaze you.
Did you know, for example, that the subject is sharper the *closer* you get to it?!... :-)
Anyway, here's the result. I photographed a watch first using a 40watt bulb, but with a 100watt from there on in. For the rest of the shots I varied the distance from the camera to the watch, the focal length (zoom), and the aperture/shutter speed.
The shots on the left are the full-size photos, and then I show a crop/zoom in on the face of the watch:
Conclusion: Macro mode with high F number and well lit gives the sharpest result (never!)
No matter what changes I made to aperture/shutter when I was 80cm away from the watch I couldn't improve the sharpness. Basically I just needed to get closer.
So, generally, I reckon still life is best photographed as close as possible for framing, well-lit, and wide-angle? (By wide-angle, I mean 38mm or thereabouts)
zapgrafx: Try increasing the aperture in macro mode to see if it improves the overall sharpness. I was originally going to comment that the '4' was out of focus because of low-light, but I've thrown my original theory out the window. I think in your case the shallow DOF has a lot to do with the softness. |
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