Help...New lens doesn't sync with flash?

Canon EF 24-70mm f/2.8L USM

12/17/2006 06:07:25 PM · #1

I just got this lens here, and after playing around with it for a little while I noticed that it doesn't sync up with the on-board flash. Identical settings which come out using a different lens look fine, but when I try to fire the flsh with this lens on, it's just as if I didn't fire it at all.

Is this a defect in the lens, or do some lenses just inherently not work with flashes?

dwterry

Canon EOS-1D Mark III

12/17/2006 06:16:23 PM · #2

The question in my mind is ... how does a lens not sync up with a flash?

All that the lens has to do is shut the aperture down to the appropriate f/stop at the time of the exposure. So if this lens is working correctly *without* the flash, then it seems that it should work fine WITH the flash as well. The lens shouldn't have to know anything at all about a flash... it works the same way with or without.

I could be wrong, I just don't see the connection.

Bear_Music

Samsung Galaxy S24, S24+, S24 Ultra

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

12/17/2006 06:17:45 PM · #3

I can't think offhand why a properly functioning lens should have any effect at all on what happens with the flash. Or an improperly functioning one, for that matter. Does the lens work right otherwise? It's a mystery to me. I suppose it may have something to do with an improper electrical connection, but it seems to me you are saying the flash actually fires but it doesn't LOOK like it fired...

Can you be more specific?

R.

dwterry

Canon EOS-1D Mark III

Canon EF 24-70mm f/2.8L USM

12/17/2006 06:24:12 PM · #4

Perhaps if you post a couple of example photos (with EXIF data intact) both with this lens and another, maybe we can figure out what is happening based on the EXIF data.

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

12/17/2006 06:26:28 PM · #5

I suspect the flash is not firing, posibly because there is a communication problem that's preventing proper metering? This is pure speculation, however.

Samsung Galaxy S24, S24+, S24 Ultra

12/17/2006 06:56:48 PM · #6

Alright, give me a moment and I'll post some shots.

Bear_Music

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

12/17/2006 07:01:05 PM · #7

Originally posted by dwterry:

Perhaps if you post a couple of example photos (with EXIF data intact) both with this lens and another, maybe we can figure out what is happening based on the EXIF data.

That would be my best guess also: I doubt the flash is firing at all. And this would seem to suggest screwed-up communications. But I don't know enough to understand why if this were the case the camera takes any pictures at all... I am ignorant, I tell you, ignorant, oh master...

Can this have anything to do with the fact that he got for 20 bucks on ebay a lens with a $300 MSRP?

R.

12/17/2006 07:04:12 PM · #8

The flash is firing both times. All I did was swap the lens. Otherwise, the lens works absolutely fine.

12/17/2006 07:11:16 PM · #9

Originally posted by modgethanc:

The flash is firing both times. All I did was swap the lens. Otherwise, the lens works absolutely fine.

If you mount the suspect lens and shine a flashlight inside of it, can you see the aperture opening & closing when you change the setting on your camera?

_eug

Nikon AF Nikkor 50mm f/1.8D

12/17/2006 07:18:45 PM · #10

Originally posted by Demento_1974:

If you mount the suspect lens and shine a flashlight inside of it, can you see the aperture opening & closing when you change the setting on your camera?

The problem with this is that until one presses the shutter ALL THE WAY DOWN, a lens is ALWAYS at it's widest aperature. This is why some cameras come with an "DOF Preview".

12/17/2006 07:23:20 PM · #11

Originally posted by _eug:

Originally posted by Demento_1974:
If you mount the suspect lens and shine a flashlight inside of it, can you see the aperture opening & closing when you change the setting on your camera?

The problem with this is that until one presses the shutter ALL THE WAY DOWN, a lens is ALWAYS at it's widest aperature. This is why some cameras come with an "DOF Preview".

My camera supposedly has DOF preview....but even then, there's too much glare for me to see all the way down the lens. If anything's moving, I can't tell. However, when I take two pictures with all the same settings except for different apretures, I get appropriately over and underexposed images, which means the aperture should be opening and closing properly.

Message edited by author 2006-12-17 19:26:03.

_eug

Nikon AF Nikkor 50mm f/1.8D

12/17/2006 07:27:41 PM · #12

Originally posted by modgethanc:

However, when I take two pictures with all the same settings except for different apretures, I get appropriately over and underexposed images, which means the aperture should be opening and closing properly.

I'm assuming this test is WITHOUT FLASH?

12/17/2006 07:28:09 PM · #13

Originally posted by modgethanc:

Originally posted by _eug:

Originally posted by Demento_1974:
If you mount the suspect lens and shine a flashlight inside of it, can you see the aperture opening & closing when you change the setting on your camera?

The problem with this is that until one presses the shutter ALL THE WAY DOWN, a lens is ALWAYS at it's widest aperature. This is why some cameras come with an "DOF Preview".

My camera supposedly has DOF preview....but even then, there's too much glare for me to see all the way down the lens. If anything's moving, I can't tell. However, when I take two pictures with all the same settings except for different apretures, I get appropriately over and underexposed images, which means the aperture should be opening and closing properly.

If you take photos without the flash, whilst maintaining the same settings, what are your results? (use a desk lamp or similar to light your subject, if required).

12/17/2006 07:28:09 PM · #14

Originally posted by _eug:

Originally posted by modgethanc:
However, when I take two pictures with all the same settings except for different apretures, I get appropriately over and underexposed images, which means the aperture should be opening and closing properly.

I'm assuming this test is WITHOUT FLASH?

Yes.

Samsung Galaxy S24, S24+, S24 Ultra

12/17/2006 07:28:28 PM · #15

Originally posted by modgethanc:

Originally posted by _eug:

Originally posted by modgethanc:
However, when I take two pictures with all the same settings except for different apretures, I get appropriately over and underexposed images, which means the aperture should be opening and closing properly.

I'm assuming this test is WITHOUT FLASH?

Yes.

Beat me to it :)

Bear_Music

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

12/17/2006 07:29:53 PM · #16

Originally posted by modgethanc:

This isn't an issue of how MUCH the aperture is stopping down; it's some sort of a synch issue. For some reason the flash is firing after the shutter actuation has come and gone, or before the shutter actuation has happened, I think.

R.

Message edited by author 2006-12-17 19:30:58.

Sigma 24-70mm f/2.8 EX Aspherical DF for Canon

12/17/2006 07:33:42 PM · #17

Well, the timing is far too fast for me to be able to do with a stopwatch...if I had the means, I'd test to see how long after I push the button that the shutter goes off. If we're assuming the flash fires the same after I push the button no matter what lens I have on, then it's that the shutter is delaying a split second for every shot with my new lens, regardless of whether or not the flash is going.

Right?

hankk

Canon EOS-5D

12/17/2006 07:38:25 PM · #18

Try calling Sigma's support-they were very responsive when I called.

You may want to check the lens without a flash. Take a working lens and set both lenses to the same aperture (say f/8) and set shutter speed for a good exposure. Do the pictures look the same?

12/17/2006 07:41:55 PM · #19

I think if all else fails I might try calling Sigma about it. Meanwhile, the pictures look just fine when I'm shooting without the flash. And I don't really use the on-board flash at all really, so it won't be that big a tragedy if it just doesn't work (I mean. I got the lens for $20.) just a minor annoyance. And when things puzzle me I want to figure out why.

These were taken right when the lens came out of the box.

12/17/2006 07:49:00 PM · #20

Originally posted by hankk:

New lens:

Working lens:

Both at F 6.3 and a shutter speed of 1/3s.

Message edited by author 2006-12-17 19:49:44.

12/18/2006 04:16:47 PM · #21

Originally posted by eBay seller:

You are correct. It will not work properly with the built in flash.

This lens was designed before the Sony/Minolta DSLR's ever existed.

Sony changed some parameters in the flash operating system which obviously could not have been known by Sigma and incorporated within this lens.

As a result, assorted non Sony lenses and accessories might not operate properly in all modes on Sony DSLR's.

This is why we only say that it will MOUNT and say nothing about automation:

" Will mount to ANY Konica Minolta Maxxum or Sony Alpha Film or Digital SLR Camera Including..." because it is not feasible to determine which exposure modes the lens will and will not work in on with the many camera models it can fit.

We have checked with Sigma and unfortunately they claim that with the Sony, a lens firmware upgrade/change can not correct the problem.

Despite the above, this lens is being used my most owners due to its exceptional performance at an unbelievable low price, and just do not use it with the camera's built-in flash.

It can be used with various external flash units.

I got this reply from sending a message to the seller on eBay.

12/18/2006 04:20:59 PM · #22

Originally posted by modgethanc:

Originally posted by eBay seller:
You are correct. It will not work properly with the built in flash.

This lens was designed before the Sony/Minolta DSLR's ever existed.

Sony changed some parameters in the flash operating system which obviously could not have been known by Sigma and incorporated within this lens.

As a result, assorted non Sony lenses and accessories might not operate properly in all modes on Sony DSLR's.

This is why we only say that it will MOUNT and say nothing about automation:

" Will mount to ANY Konica Minolta Maxxum or Sony Alpha Film or Digital SLR Camera Including..." because it is not feasible to determine which exposure modes the lens will and will not work in on with the many camera models it can fit.

We have checked with Sigma and unfortunately they claim that with the Sony, a lens firmware upgrade/change can not correct the problem.

Despite the above, this lens is being used my most owners due to its exceptional performance at an unbelievable low price, and just do not use it with the camera's built-in flash.

It can be used with various external flash units.

I got this reply from sending a message to the seller on eBay.

Now he tells you :)