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Sony 24-70mm F4 Vario-Tessar T* FE OSS

02/08/2009 11:34:34 AM · #1

I was practicing with a white backdrop at home. I had one strobe on the right bouncing on a white umbrella, another one on the left thru a soft box. The flash on camera with a diffuser. At the beginning the photos were coming out just ok, I tried to experiment with other set ups and all of the sudden, the photos started to come out with the background grey. It didn't matter what I did to change it to the original set up, it did not change the grey results. I even customized the WB telling the camera that the backdrop was white..nothing. Put a flash to blown out the background, nothing. Frustrated I gave up. I have included two photos for you to see. Can somebody please tell me what am I doing wrong here??? Thanks a lot. I really appreciate it.

Message edited by author 2009-02-08 12:35:54.

ralph

Nikon Z9

02/08/2009 11:43:58 AM · #2

please post the details (shutter/fstop/iso)
my guess you changed modes & are suddenly triggering your flashes on preflash

Bear_Music

Samsung Galaxy S24 Ultra

02/08/2009 12:05:16 PM · #3

The darker image shows shadow on backdrop consistent with onboard flash only. So in all likelihood the two remote flashes did not trigger at all within the timespan the shutter was open. White balance has nothing to do with it BTW, the colors are neutral enough, it is just underexposed.

Tell me, could you SEE the remote strobes flashing when you shot? If so, it's a synch issue. If they aren't flashing at all it's a connectivity issue maybe.

Set your camera at shutter priority (Tv on the dial), 1/60 sec, and duplicate the rest of the setup and see what happens. This *might* have been caused by a shutter speed faster than 1/250, I think...

R.

ETA: The second image (underexposed one) has been stripped of EXIF, but the first image shows following:

Exif Sub IFD

* Exposure Time (1 / Shutter Speed) = 1/125 second = 0.008 second
* Lens F-Number/F-Stop = 10/1 = F10
* ISO Speed Ratings = 100
* Original Date/Time = 2009:02:07 23:37:44
* Shutter Speed Value (APEX) = 458752/65536
Shutter Speed (Exposure Time) = 1/128 second
* Aperture Value (APEX) = 434176/65536
Aperture = F9.93
* Flash = Flash fired, compulsory flash mode

Message edited by author 2009-02-08 12:13:07.

02/08/2009 12:22:26 PM · #4

Originally posted by ralph:

please post the details (shutter/fstop/iso)
my guess you changed modes & are suddenly triggering your flashes on preflash

It was 1/125
F10
ISO 100

Thanks a lot

02/08/2009 12:28:11 PM · #5

Originally posted by Bear_Music:

First of all thank you for taking the time...
Yes they were flashing with the flash on camera. I'll try the set up you recommend to see if it works. I just started studying photography on my own, so a lot of technical terms are new to me, specially experimenting in a studio, so please any help you can give me wil be very well appreciated.

Canon EF 17-40mm f/4.0L USM

02/08/2009 12:38:59 PM · #6

Originally posted by Bear_Music:

ETA: The second image (underexposed one) has been stripped of EXIF, but the first image shows following:

Exif Sub IFD

* Exposure Time (1 / Shutter Speed) = 1/125 second = 0.008 second
* Lens F-Number/F-Stop = 10/1 = F10
* ISO Speed Ratings = 100
* Original Date/Time = 2009:02:07 23:37:44
* Shutter Speed Value (APEX) = 458752/65536
Shutter Speed (Exposure Time) = 1/128 second
* Aperture Value (APEX) = 434176/65536
Aperture = F9.93
* Flash = Flash fired, compulsory flash mode

I saved the second photo differently so you could see the settings, everything was just the same only the ISO was 320. I think is a synch problem, these are old strobes that I bought just to practice.

soup

Canon EOS-30D

02/08/2009 12:56:34 PM · #7

are you sure the ISO was at 320 on the underexposed image ?

i would think with everything else being equal and higher ISO would have produced the opposite result. ie: the higher ISO setting would have caused an overexposed result - not underexposed ?>

Canon EF 24-105mm f/4.0L IS

02/08/2009 01:05:01 PM · #8

Originally posted by soup:

That's what I thought, but it did not change a bit...

Mark-A

Canon EOS-5D Mark III

02/08/2009 02:50:27 PM · #9

I had this happen a couple of times when I first started using flashes with white background images, it was a problem with light positioning, all the lights were basically flooding the whole image with almost the same amount of light causing them to be extremely flat and looking underexposed.

I would start by trying the following, reposition your Key light at camera left or right at about 45 degrees, use your fill light pretty much straight on from the camera and move your subject further away from the backdrop (and push your backdrop light up a stop or two), make sure you do not bounce the on camera flash up off the ceiling as this was a definite contender for a major contributor in the problems as it killed all the other lights! This is just to make sure everything is working correctly - do you have a meter?

Canon EF 24-105mm f/4.0L IS

02/08/2009 05:27:00 PM · #10

Originally posted by Mark-A:

Thanks a lot, I moved the lights to different position, what I cant understand is that I moved everything back to the set up of the first one and still did not work, but definetely I will try to do what you are telling me. Yes I do have a meter.

Mark-A

Canon EOS-5D Mark III

02/08/2009 05:36:50 PM · #11

In that case as you have a meter I would just do something really simple like f8 key and fill, leave the background light out of the equation in the first shot and see what happens (so just to be clear, use your off camera flash @45 degrees camera right set at f8, then if your on camera flash is being used as your fill light put your camera on a tri-pod and meter that also at f8 - ensure no other lights are used), set your camera to manual f8 : 1/125 : ISO 100 and see how it comes out. If all is ok add in the background light and see how that comes out.

Message edited by author 2009-02-08 17:38:35.