D-Flash 40 Technique beginner's question

[alex_stein]

Hi all -

 

I'm a new owner of a D-Flash 40, which I use with my 503CX. I'm more familiar

with E-TTL flashes from using them with my Canon, so I'm still learning how to

work with the Hasselblad, and have a couple of questions:

 

I'm having trouble grasping the limitations or preferred usage of the flash. For

example, when shooting indoors with the flash as the primary source of light, if

I'd like a relatively high shutter speed to reduce camera shake and a somewhat

closed down aperture to increase depth of field, is there a way to determine

these limits without shooting a test shot and looking for the flashing exposure

indicator in the viewfinder? I can't imagine this is practical in all

situations, so is there a good starting point if you know your ISO?

 

Like I said, this is beginner stuff, so please be patient.

 

Thanks!

 

-Alex

[paul_gardener]

Alex,

 

I do not think I have to be patient. Your question is quite understandable.

The guide number for the D 40 is about 40.

This means distance multiplied by aperture: 20 meters at F2 or 10 meters at F4 and so on. Guide numbers refer to 100 ASA film.

 

When lighting depends for the larger part on the output of the flashunit shutterspeed is less important.

Fast shutterspeeds decrease the amount of available light that will show in the exposure. The flash is much shorter than the shutter speed.

When using flash, only the aperture determinnes the amount of light that reaches the film.

 

Use the guide number as a rule of thumb.

It means the maximum possible distance.

The D40 is a TTL or rather OTF system.

OTF means of the film, light reflected by the film is measured to control the output from the D40.

 

If you decide the D40 is only needed to fill in existing light set the film speed dial on the left of the camera to a higher than actually used film value. With 100 ASA film select 200 or 400 ASA.

You fool the control system of the flash unit and get half or only one quarter of the nominal flash output.

[alex_stein]

Paul -

 

Thenks for the clear and informative response! Knowing the guide number (I should have guessed!) helps quite a bit, plus the math. This quite useful.

 

I'm still not sure why my wife, sitting mere feet across a table from me, came out severely underexposed when I shot her at, I believe, F11. I'm not 100% that was the aperture, but even at the lens' maximum (F22) I should have had sufficient light to reach almost 2 meters, correct (I'm quite sure I didn't shoot at F22).

 

Could other factors contribute to this?

 

Thanks again!

 

-Alex<div></div>

[russ_britt3]

Paul gave a very good answer......The flash will stop the action....but with the hassey you can use any shutter speed you want.

[danny_wong2]

What shutter speed are you shooting at?

 

Although the leaf shutter syncs at 1/500 second but it might not be capturing the full flash duration of the flash unit that you are using

[paul_gardener]

Alex,

 

I understand it is disappointing when a simple shot like the one you made did not come out as intended.

 

Did you set the film sensitivity at the side of the camera at the same value of the film you used?

 

The reflector of the D40 can be set to tele or wide position.

If it was set at tele a good deal of its output may have missed the subject.

 

Leaf shutter lenses can be used at all speeds.

The flash contacts can be adjusted and may need correction.

Just to be save have the lens you used checked for correct working of flash contacts.

 

Finally the D40 may not have its full output and should be checked.

 

Does the little red dot top left in the viewer of your camera light after an exposure?

You can also test this without film by fitting the plastic cover with

gray area to the camera.

The cover was provided with a D40 and also with the camera when sold new.

It can still be ordered. It will cost only a few USD.

[alex_stein]

Thank you again, Paul, and Russ and Danny. I don't recall the shutter speed on the shot posted, but it definitely was not 500.

 

I'm going to take a roll of 220 film this weekend and do a series of tests at various f-stops and distances to find out whether I'm getting expected results. Paul, you were correct - I had the reflector set to tele when I took that shot.

 

Finally, can you provide a bit more information about the plastic cover you mentioned? I assume it's some sort of cover to fit the back of the camera, in lieu of a film back? I bought both my camera and flash used, and neither came with such an item.

 

Thanks again!

 

-Alex

[paul_gardener]

Alex,

 

The cover is officially known as rear protective cover multicontrol.

All bodies were supplied with a front and rear cover unless you buy a kit then the rear lens cover and the front body cover are not in the package.

Later bodies offering OTF flash control had the multi control version of the protective cover.

 

The part number for the multi control cover is 51070.

Earlier covers will also protect the camera but do not have the grey

reflection area needed to reflect light to the sensor in the front part of the camera.

Any Hasselblad dealer should be able to supply one.

If you cannot find a dealer in your area contact Hasselblad USA in New jersey.

They will be able to help you for sure or direct you to the nearest dealer.

 

If you happen to live in Massachussets contact David Odess.

He is a qualified Hasselblad tecbnician and also sells the V system.

He will help you gladly.

[alex_stein]

Hi Paul -

 

Thanks, I'll order one straight off. In the meantime, as promised I ran a roll of 220 film through the camera tonight, ISO 100 E6. Indoors, ambient was EV6 down to EV2, distances from 1.2m to about 15ft. I consistently got the flashing exposure indicator in the viewfinder at all distances, all f-stops from 4 to 11 and even 16. However, when my model (wife) insisted on a "nice" picture to finish off the roll, I moved in closer and attempted to bounce off the ceiling. No flashing light. Chagrined, I moved back up to 2.8 and aimed the flash directly at her. Still no light! So this is what prompted my original post. It seems sometimes identical shots from the same location will not indicate as properly exposed.

 

Obviously, I'll know a lot more on Monday when I get the film back from the lab, but it does make me nervous going to an event and not being sure I'll even know whether I missed a shot or not.

 

Thanks!

 

-Alex

[alex_stein]

Well, for anyone still following this thread, it looks like there was an issue with my metering system. My roll came back almost completely black, except for some shots which were absolutely blown out. I took the body and flash in to Steve's Camera Repair here in LA, and the diagnosis is the ASA-setting mechanism was broken into two pieces! He's replacing that and we'll go from there. I'm a bit mystified why the readings would be so far off both positively and negatively, but who knows how the camera meters things if the ASA setting is off.

[paul_gardener]

Alex,

 

Might be a good time to upgrade your flashcontrol to the later ones that have a wider range e.g. Your camera has 800 ASA as max filmsetting where the later 503CW has 3200 ASA.

It may not seem practical but the setting is also used to fool the flashunit when using it to fill in only.

[alex_stein]

Hiya Paul -

 

I did ask about the upgrade, but the quote was a bit ridiculous, on top of the repair. I'm fine with 800 for now, as I don't think I'll be shooting anything faster than 400 in the near future, and will reconsider the upgrade later.

 

In the meantime, just ran the first post-repair roll through, and it's looking much, much better.