Using flash with legacy lenses and the G1

[dbookbinder]

I've been experimenting with various adapters and manual-focus lenses on my G1 and am wondering if there is any way to have the camera control the flash exposure. Metering works fine without the flash, but I have yet to find a way of using the built-in flash that doesn't involve a lot of aoerture and ISO guesswork. Am I missing something (in which case, what am I missing), or is this the nature of the beast?

Thanks,
David

 

[oftheherd]

I am not sure I understand your question. It you are asking something specific to the camera, I can't help. But it sounds like you are asking how to make a flash work.

If that is so, the first thing you need to be sure of is that you have a shutter speed that is all the way open, which should be so if the camera flash if firing. Next you need to know the guide number of the flash. Hopefully that will be in your owner's manual. With that, you can figure the proper aperture for the distance to your subject. If you don't know the guide number and it isn't in your owner's manual, you will just have to test. Do you have the guide number?

Sorry, I don't recall the exact way to test. I remember having read a method a long time ago, but it didn't stick as all my flashes as the time came with manuals telling me what the guide number was. Somebody with a longer/better memory may come up and help.

Again, sorry if I have misunderstood your question.

 

[dbookbinder]

Clarification

Clarification

Sorry, I'll try to be more clear. This is a question specifically about the G1, though I suppose the principal would apply to other m4/3 cameras using manual, legacy lenses.

The G1 meters correctly, with no intervention on my part other than setting the aperture to the shooting aperture , when I am using legacy lenses with an adapter. Since it appears to be able to meter correctly when there is no electrical connection between the lens and the camera (the adapter is just a piece of aluminum with the G1 mount on one end and Nikon mount on the other), I am wondering if there is also a way to set up the G1 so that it meters correctly when I am using the built-in flash.

Thanks,
David

 

[Pickett Wilson]

The Pany Man does not use flash. He lets his unwavering vision illuminate the scene. 😉

I suspect that the lenses designed for the G1 transmit information to the flash that manual lenses do not.

 

[dbookbinder]

Yes, of course they do. What I'm looking for is someone who has found an effective and reliable way to use the G1 with legacy lenses that do not communicate electronically with the camera.

It seems likely there is a way... but it is not apparent, nor is it documented in the manual. It would be nice, in particular, to be able to use fill flash with the G1 and the portrait lenses I am adapting from my Nikons.

 

[oftheherd]

Well, given what you want to do, if there is on work around that someone has found, you can still figure out how to use the builtin flash if you know the guide number. Are you familiar with how to use guide numbers, distance, and aperture? I don't have it at hand. You can look it up yourself, or if you can't find it, let us know. I will look up the formula, give it to you and explain it. It really isn't hard. It's what we all used to do years ago before automatic auto-exposure electronic flashes.

 

[charjohncarter]

Should be easy find the Guide Number of the flash (you have to use Manual flash setting on your camera) and then use the formula: Guide Number [for your ISO] = [Flash to Subject Distance] x [F-Stop]. This is the way normal people do it. Well, maybe not normal but people that do flash.

If your camera doesn't have a manual flash setting then you will have to use a separate flash unit and trigger it with your camera flash and a slave trigger on your off camera flash.

 

[srtiwari]

The Guide number on the G1 is 36, according to this...(That sounds kind of High for a pop-up flash)

http://www.dpmag.com/buyers-guide/cameras/slrs/under-1000/panasonic-lumix-dmc-g1.html

 

[oftheherd]

The Guide number on the G1 is 36, according to this...(That sounds kind of High for a pop-up flash)

http://www.dpmag.com/buyers-guide/cameras/slrs/under-1000/panasonic-lumix-dmc-g1.html

I didn't see an ISO, but it is probably at ISO 100. For the OP, at that ISO, divide the guide number by the distance for your aperture. For example, if the distance to the subject you want illuminated is 8 feet, 36/8 = 4.5; set your lens aperture to f/4. But be sure that is the guide number for ISO 100.

 

[charjohncarter]

Is it in meters or feet (be sure you are using the same for distance and GN)? Generally, 100 ISO is used but they could be misleading us. And again, be sure the flash is on MANUAL, if it is on TTL you will never get it right.

 

[JoeV]

I'm not sure if this is helpful, but I've tried using the onboard G1 flash as fill, with manual focus lenses as well as the kit Lumix lenses. The problem with the onboard flash is that, even with Lumix brand, electronically-controlled lenses on the camera, you really don't have a bona fide fill flash mode for the G1 to start with. So you have to improvise, which I've tried doing by simply lowering the power output of the flash in the menu to something like -3, then take a series of test shots to determine best exposure. The problem with this method is that it's totally manual, and doesn't automatically compensate for the subject distance (too close a subject will over-expose via flash) nor the scene's brightness. It's totally hit and miss, experimental in nature with the onboard flash and the Lumix lenses, so it'd be about the same using a legacy lens, with the difference being that you control the aperture of the legacy lens on the lens barrel itself, rather than through the on-screen display via the thumb wheel.

If anyone else knows how to get a good fill-flash using the onboard flash and the Lumix kit lenses I'd like to know, because otherwise it's about the same as shooting with manual lenses for the lack of control that is offered. I think it's best to say that the G1 series are really not adept flash-operated cameras.

I'd have rather Panasonic had eliminated the onboard flash on the G1 and made the top "camel's hump" a bit smaller, but that's just me.

~Joe

 

[srtiwari]

The fastest shutter speed I can adjust on the G1, with Flash (Onboard or External) is 1/160 sec. I wonder if this would work-

Camera on Shutter priority with speed set to 1/160 sec.
Flash out put adjusted to -1 EV
Intelligent ISO "On" upto ISO 400


(This should also work using Legacy lenses, if one dials in the aperture manually to get +/- 0 over- or under-exposure, even before pressing the shutter.)

 

[dbookbinder]

Thanks for all the ideas. I will hopefully have some time to test them out this weekend and will report back if I find anything of interest.

 

[dbookbinder]

Reporting back, belatedly...

Reporting back, belatedly...

What appears to work best for flash shots and legacy lenses is to

1. set the mode to Manual or Shutter Priority
2. set the ISO to a non-Auto setting (100, 200, etc.)
3. set the aperture to (guide number for ISO)/(distance to subject), where the guide number is 36 feet at ISO 100
4. adjust the shutter speed to 160 (or lower, if you want to include some ambient light).

I am guessing that fill flash might work if I expose for the brighter parts of the image and make sure I'm using an f/stop that is maybe two stops below the aperture the above setup would yield, thus effectively limiting the amount of light the flash is contributing to the exposure. I'm also guessing I'd have to use one of the Slow sync methods. However, I have not experimented with this method yet.

More anon,
David