Dimage 7Hi External Flash Setup??

[Softweigh]

Hi All

I am trying out a dedicated Sigma EF500 SG ST (the Minolta model) and although it fires the flash unit perfectly on my Dimage 7Hi most shots are horribly overexposed.

Do I need to change anything in Camera Setup mode?? Like "Flash Mode" and "Flash Control" At the moment it seems like the flash is firing at full power and is not getting the correct EV values from the camera. It is one of recommended models that can be used from dyxum.com's page and this unit (on loan) definately has the Minolta protocol so it's the right model. I don't want to buy it if it doesn't work right!!!

Any one else got any ideas for me???

Many Thanks

Chris

[JimC]

Try using different camera and flash settings to see if that makes any difference.

But, the problem you're describing makes me think you've probably got an older flash that's not compatible with digital. That's a typical problem with a flash that's got firmware that was designed for a Minolta Maxxum film camera. When you get a flash that's not compatible with digital, they'll usually fire a full power, regardless of camera settings.

That's one reason I mentioned this in the earlier thread (bold in the below quote added for emphasis)

http://forums.steves-digicams.com/fo...mp;forum_id=20

You see mixed reports on the Sigmas from Konica Minolta and Sony dSLR owners for flash accuracy. Personally, I'd probably avoid them (especially if they have an earlier serial number).

I also said this later in the same thread:

I wouldn't assume that you'll get perfect exposure, especially with a 3rd party flash. Flash metering is a bit complicated with digital. Because of the reflectivity of a digial camera's sensor, off the film metering is no longer used. Instead, a digital camera uses a very short metering preflash. Based on the amount of reflected light the camera sees, it determines the length of the flash burst needed. There is no flash metering during the exposure. Depending on the flash, you may see issues. For example, the firmware in some third party flashes may assume the wrong zoom settings and more. With older Sigmas, you sometimes see reports of compatibility problems.

You probably got a Sigma flash that is not using firmware new enough to work with Digital Cameras (even though it may work fine with a Maxxum Film camera).

But, I've seen reports of exposure issues with newer Sigma flashes, too (usually underexposure versus overexposure).

Here's a quote from an old post discussing compatible serial numbers of the Super models. But, I don't know of a list like that for the cheaper non-Super model.

http://forums.steves-digicams.com/fo...=20&page=1

In a dedicated flash, I'd personally avoid the Sigmas. I've seen multiple KM DSLR owners that decided to return them, sometimes even after the flash made more than one trip to Sigma for recalibration (and sometimes coming back with worse exposure accuracy than they had to begin with).

Some of the newer serial number Sigmas are supposedly using more compatible firmware. But, reports I've seen are a "mixed bag" (some owners report exposure problems, some owners report they work OK).

Here is a chart that may help out if you can look at the serial number on a Sigma EF 500 DG Super, if you really want to consider using one:

Serial # 1 or 2xxxxxx are non Dg and are not compatable with KM5D/7D/a100

Serial # 3 to 6xxxxxx DG MA version. Flash needs to be set to FP (high speed sync) using the sel button on the flash, and setting the camera ADI Auto.

Serial # 7xxxxxx DG MA-ADI version. Set flash to FP and the camera to ADI Auto.

Serial # 8xxxxxx Default setting is FP. No sel changing necessary.

Note that even with the newer (supposed dSLR compatible) models , I've seen it reported that some compensation may be needed, depending on whether or not you're bouncing.

Strangely, most people report that exposure is fine when the flash is off camera using wireless, even those with severe exposure problems otherwise.

There are a number of other choices around now, too. But, be very careful. Most dedicated flashes designed for the Minolta Maxxum flash shoe were designed for film cameras. Most of these are not compatible with KM or Sony dSLR models and will only fire at full power if you try to use one.

Frankly, in dedicated flash, I'd avoid the Sigmas (as I pointed out in the previous thread you started). I've seen too many issues reported with them.

[JimC]

Since it's a loaner, I'd return it if camera and flash settings don't make any difference.

If you want a dedicated flash, I'd suggest sticking with a KM or Sony model that's compatible with your camera.

[Softweigh]

Hi Jim

Many thanks ..this one is a fairly recent ST not a super but is still on the compatible list. I think it just might be wise as you suggest and wait patientlyfor a KM 3600 or 5600 which will definately work correctly.

I see on eBay.com Bower "claim" to have compatible units for the Dimage7 from as little as $39.99 which seems too in-expensive to actually work correctly as a dedicated unit.

Thanks once again!! I'll keep my eyes peeled for a 3600/5600

Chris

[Softweigh]

Hi Jim

I have found a manual flash unit that might work well with the Dimage (using the standard sync plug) It's a Hanimex TZ36 and I have carefully checked on the site you gave me on trigger voltages and they list it as being a 4.2v trigger so that definately will not hurt the camera.

If you get a chance can you give me some hints on this unit (it's on eBay and will be pretty cheap) It seems to have full/1/2 and 1/4 power and three "auto" modes. The camera will obviously be a "dumb" connection to the flash (purely a trigger) but what do the auto modes do??? I am figuring they would be something to do with range/aperture and when the thyristor says "cutoff"????

I know a 5600 would be better but I don't really want my flash to cost twice what I paid for the camera!!!

Your advice is really helpful and much appreciated

Chris

[VTphotog]

Sounds fairly standard for an auto-thyristor flash. There should be a table printed on the flash with exposure settings when used in the manual modes, as well as a way to calculate aperture for a given distance and film speed when in the automatic mode. There may be several auto settings for this.

The flash will have a photocell which measures the return light and turns the flash off when it receives enough. (based on the setting position)

brian

[Softweigh]

Hi Brian

Thanks! It seems to have 3 auto settings that span 3 distance ranges so I guess this means that you would get fairly consistent exposure on sayauto" A" which suggests F5.6 at ISO 100 and covers from 11' to 21'

In auto in the above case, am I right in thinking that the sensor will turn the flash off a little earlier if the subject is at 11' and a little later at 21' so the correct amount of light is used????

It has 1/16th, 1/4 and full power settings ... any idea if auto would also work at different power settings as well???

Chris

[JimC]

Yes, they measure reflected light for the Auto scale being used (which lets you know what aperture and ISO speed the camera needs to be set to). These types of flashes allow you to adjust the scale for aperture and ISO speed within an Auto Range.

You'll get more range with a wider aperture (for example, f/4 versus f/5.6) and higher ISO speed (each time you double the ISO speed, flash range increases by 1.4x).

If you want a hotshoe mounted flash, those should be easy to find, too. I'm using a Sunpak 333 Auto I got for only $25, brand new in the box from B&H. It's got tilt, swivel and zoom head with multiple auto aperture ranges, as well as manual power settings (full, 1/2, 1/4, 1/8, 1/16). GN runs from 86 feet to 120 feet at ISO 100, depending on the zoom head setting.

I use it with a hotshoe adapter like the ones I mentioned from Gadget Infinity. Here's a newer one they sell:

http://www.gadgetinfinity.com/produc...275&page=1

[Softweigh]

Thank Jim

You are a wealth of information. I got the TZ36 for AUS$35 (about US$26) The bottom bracket is missing but there is nothing a DIY fix won't sort out.

The dedicated units were just too darn expensive here!!! Besides the thyristor control will give me a bit of leeway as long as I work with the camera in Aperture Priority Mode and let it find it's own shutter speed. Besides, I still prefer to have control of what's happening rather than run full auto!!

Meant to ask again... will the auto mode work if the unit is switched to the lower power settings?? If it has a photosensitive device to measure the light reflected back then it still should be able to tell the flash when to cut off???? Obviously it will cut off a lot later if the power is lower!!

I'll let you know the results!!

Chris

[JimC]

With most flashes, the manual power settings are simply manual power (used instead of their Auto modes).

Note that shutter speed has no bearing on the amount of light from the flash the camera is seeing. That's because the flash burst is very short (usually around 1/1000 to 1/10000 second, depending on range to subject).

Use of shutter speed can be helpful to vary the amount of ambient (non flash light) seen by the camera. But, it doesn't make any difference for how much light from the flash is being seen.

Manual exposure (setting both aperture and ISO speed) is the best way to use a non-dedicated flash.