Exposure differences with Canon R7?
Aug 28, 2022 08:13:51 #
tcthome
Loc: NJ
I would try again with ISO set to Auto ISO. Helps with changing light, like maybe the sun/clouds, etc. When shooting in Continuous High Speed, It moght take a shot or two for the ISO to adjust.
Aug 28, 2022 09:04:40 #
As you have queried PhotoMechanic as being the culprit, have you used Canon's DPP to see if it gives the same results?
Aug 28, 2022 09:06:05 #
bajadreamer wrote:
Thank you for your thoughts. You are correct. Th... (show quote)
You've got a bad capacitor on the failed lamp.
Because LEDs have about 100.000 hours lifetime, often manufacturers install cheaper components to limit that (and keep selling)
Besides that, LED lamps connected to a DC source pulse at kHz frequencies, and flicker is filtered by... ya know, the failed capacitor.
Therefore, while the circuit is OK, then no flicker... until it fails
Aug 28, 2022 10:20:09 #
bajadreamer wrote:
Thank you for your thoughts. You are correct. Th... (show quote)
Glad you found the cause (and I hope the LED light was under warranty).
Cheers
Aug 28, 2022 10:26:41 #
rmalarz wrote:
There was no change in exposure. Everything stationary looks the same in each image. My guess is slight movement of the bird caused variations in the way light reflected off the feathers.
—Bob
—Bob
👍
Aug 28, 2022 10:32:18 #
bajadreamer wrote:
These 4 exposures were taken serially. These are ... (show quote)
We have to ask you if you were using the electronic shutter. This could be the problem. Essentially you are capturing very short slices of time your shutter speed dictates, but you're capturing many different slices of time. If your subject has moved during that time, then the distinction becomes apparent.
Aug 28, 2022 10:40:51 #
Aug 28, 2022 12:12:51 #
tcthome wrote:
I would try again with ISO set to Auto ISO. Helps with changing light, like maybe the sun/clouds, etc. When shooting in Continuous High Speed, It moght take a shot or two for the ISO to adjust.
Thank you for your thoughts. It turns out a faulty LED lamp was the cause.
Aug 28, 2022 12:13:26 #
recb wrote:
As you have queried PhotoMechanic as being the culprit, have you used Canon's DPP to see if it gives the same results?
Thank you for your thoughts. It turns out a faulty LED lamp was the cause.
Aug 28, 2022 12:16:05 #
LEWHITE7747 wrote:
We have to ask you if you were using the electronic shutter. This could be the problem. Essentially you are capturing very short slices of time your shutter speed dictates, but you're capturing many different slices of time. If your subject has moved during that time, then the distinction becomes apparent.
No I was using mechanical shutter. Oddly, the previous day I was using the electronic shutter at 15 fps; the exposures were perfect (the LED light was working well), but I had lots of rolling shutter effects on the hummingbird wings. So I then switched to mechanical; no rolling shutter, but the exposures were wacky.
It turns out a faulty LED lamp was the cause.
Aug 28, 2022 13:54:30 #
Since the blown highlight indicator on the flower is the same on all shots, it must be a change in the reflectivity of the bird as it flaps its wings, not a change of exposure.
Aug 28, 2022 15:40:07 #
PHRubin wrote:
Since the blown highlight indicator on the flower is the same on all shots, it must be a change in the reflectivity of the bird as it flaps its wings, not a change of exposure.
Two factors. There is a difference in the exposure of the flowers; it is not as obvious as the birds. The primary reason for that is that the faulty LED light was aimed at the likely location of the birds not the flower. The filtered sunlight was coming from above and to the left. The LED light, located below and to the right, was intended to soften the shadow on the underside of the bird. Because the light was pulsating sometimes it worked well and others overexposed the bird.
Aug 28, 2022 21:29:48 #
I think the specific wing position for each shot is the cause for the variations of exposure on the bird, as the wing partially blocks the amount of light falling on the bird.
Aug 29, 2022 01:05:55 #
amfoto1
Loc: San Jose, Calif. USA
It's not the camera.... the ISO, shutter speed and aperture were unchanged.
It's probably the lights. You mention using LEDs. Some of those flicker and will cause changes in exposure. It can show up at certain shutter speeds, but not at others. Your camera has an "anti-flicker" feature you can enable to counteract this, if it's occurring.
Another possibility is that it's just the reflectance from the bird's feathers as it moves slightly from shot to shot. Notice how the gold feathers show up more in one of the images, the belly feathers are more exposed and white in another, then are somewhat shaded by it's wing in a third image. The reason I suspect this is exposure of the flowers at the top of the images seems the same across all four. It's only the bird where the exposure changes.
It's probably the lights. You mention using LEDs. Some of those flicker and will cause changes in exposure. It can show up at certain shutter speeds, but not at others. Your camera has an "anti-flicker" feature you can enable to counteract this, if it's occurring.
Another possibility is that it's just the reflectance from the bird's feathers as it moves slightly from shot to shot. Notice how the gold feathers show up more in one of the images, the belly feathers are more exposed and white in another, then are somewhat shaded by it's wing in a third image. The reason I suspect this is exposure of the flowers at the top of the images seems the same across all four. It's only the bird where the exposure changes.
Aug 29, 2022 04:38:12 #
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