FUJI GA645 flash questions

[dnmtsn]

Hi all, I'm new here and for a couple of months I've been the proud owner of a wonderfull GA645. I like this camera a lot, it is my favourite camera among the few that I own. But I can't seem to understand how to use the built in flash. I am not using flash on my other cameras so I don't know much about it; I only want to use the on-camera flash for fill and for low light, close distance shots. So here it goes:

I want to shot a scene in low light, and I am well within the range of the little on-camera flash (3-4 meters at ISO1250). I am shooting tri-x rated at 1250, (diafine) with the ISO set accordingly on the camera. How to shoot?
If I shoot in programmed mode, the camera always wants to shoot at f/8 and 1/45 and I have to rely that it will adjust flash properly. The good part here is that I can KNOW when there's enough light to shoot at 1/45 and f/8 with the flash popped up because if there's not, it will blink. But if it blinks, there may not be enough light for f/8 but I can open the lens to f/4, can I? And then it will not blink, right? Well, wrong: if I set the camera to Av or manual, I can't open up the lens unless I lower the ISO... so to open the lens to f/4 in Av I have to drop ISO from 1250 to 400. If I keep ISO at 1250 it doesn't let me go below f/8. I don't know why, but this is what it does. So I drop the ISO, go to Av, set diaphragm at f/4 but now, the meter wants to shoot at 1/2... and my film is 1250, not 400 so the flash will think it's 400 and will output too much light and overexpose my photos, right? So this is where I really start to get lost. I think there's no reason to shot at 1/45 only, I believe this shutter can sync with the flash at any speed, or not? Can anyone shed some light on this (excuse the pun).
BTW, I did read the manual.
Thanks a lot,
Dan

 

[dnmtsn]

... this must be a really difficult one. Or it's too easy for anyone to bother. In any case, if my description of the problem is not very clear, I'll try to make it simple and shorter: can anyone give some thoughts on why I can't shoot with the on-camera flash at lower aperture than f/8 in Av or manual without lowering the ISO from 1250 to 400?
Any thoughts are greatly appreciated, thanks.

 

[dnmtsn]

External flash

External flash

me again...
As I said I know nothing about flashes and maybe the next question is a silly one, but I am not able to find an answer elsewhere: I am considering buying a Metz 36 AF-4 for my Pentax K100d; will this unit work on the fuji as well? Of course there will be no TTL, but can I expect it to work at all? If not, can anyone recommend a decent, cheap (under 100$) external flash?


Thanks,
Dan

 

[ChrisN]

You have raised a difficult question! I've never used 1250 iso film, nor used flash with my GA645, so these are interesting problems. The limits you describe are certainly wired into the programming of the camera, so it is as the designers intended.

One thing I have noticed is that there are some limits imposed in terms of the combinations of shutter speed and aperture. I normally use 400 iso film. With the aperture manually set to f/11 or smaller I can select 1/700 - the fastest shutter speed the camera offers. If I open the aperture to f/8, the shutter speed will automatically drop to 1/400 and I cannot select 1/700, even in manual mode. I have to assume that there is some sort of physical limit in the design of the shutter, that says it is unwise to try to use1/700 and an aperture larger than f/11. I guess this means the shutter and aperture use a common set of blades, and can't work quickly enough to do both jobs.

On the flash question - I don't know the Metz flash you mention, but if it is designed for the Pentax it will have three pins on the base for communicating with the camera's exposure control, plus the central pin for firing the flash, the same as the Pentax flash units. I've just tried a Pentax AF360FGZ flash on the GA645, and it seems to fire in synch with the camera shutter, with the flash set in manual or automatic mode. I haven't tested this with film, but I expect it would work ok. The camera hot-shoe is not smooth in the positions where the extra pins rest, and I think there is a chance of damage with repeated fitting and removal of the flash. I also have a Nikon SB28 flash that I have removed the extra pins from - I use it on the Pentax and any other camera with a hot-shoe mount, in manual or automatic mode. It works well and does not have problems with the extra pins shorting out or physically catching (as they are removed).

Good luck!

 

[djonesii]

I have a GA645, and honestly, when I am shooting low light events, I just set it to P mode, open the flash, and shoot. I typically use C41 developing film at ISO 400 with the ISO set correctly. I have never experimented with faster film, so have no experience.

Typically, I use the GA645 as my medium format event camera just for that reason .... the auto settings work pretty well, and it gives me a bit more leeway to cover the event and less worry about the photographic details.

For this type of photography, I find the Fuji much better than my Bronica 6454. Of course, YMMV

Dave

 

[dnmtsn]

ChrisN, thanks a lot for the reply. The thing you mention about shutter speeds depending on the aperture is actually described in the manual, at page 16; between f/4 and f/9.5 you can only use 1/400. For apertures smaller than f/9.5 you have access to the faster speed of 1/700, this is why you can set 1/700 at f/11 but not at f/8. I don't know why is the camera designed like that, but at least this limitation is documented.

But the connection between ISO and maximum aperture when using flash is not described in the manual, or I wasn't able to find it anyway; in fact the only thing related to this is a table which describes the minimum aperture that can be used in relation to the ISO setting (that's on page 28)... I find it very strange that you can't open the lens more to shoot at faster speeds with flash. And I suspect that the same limitations will apply with an external flash.

If you don't have the manual you can find it here: http://www.cwclemens.com/Fuji GA645.pdf

djonesii, that sounds reassuring. i will probably to the same in the future if I need to shoot in low light. do you have any photos posted that were shot like that? thanks,
Dan

 

[oldoc]

In low light situations, that 1250 ISO film still may not need the on-board flash. Are your photos coming back underexposed with that speed. I would try the same camera with 400 and 200 and see if it is firing. My GA645ZI I recently sold never fired the flash unless needed, and it was so automated that it was right more often than I was...

 

[dnmtsn]

oldoc, the reason I am asking these questions is for situations when even with 1250 ISO film the exposure indicators blink (indicating that there's not enough light for a properly exposed shot)...

 

[djonesii]

GA645 w/ Flash ...

GA645 w/ Flash ...

djonesii, that sounds reassuring. i will probably to the same in the future if I need to shoot in low light. do you have any photos posted that were shot like that? thanks,
Dan

In all the photos below, I used the GA645 w/ Flash, set to P mode, the film is ISO 400 Fuji.

All the party goers were to be dressed in white, and this makes it about as hard as it can be for a flash situation. The only thing worse would be a back tux beside the white dress!

This girl did not get the e-mail about white, but she was hot in red, and as a dedicated chauvinist, I snapped a few photos of her any way.

The whole film set is at:
http://www.jonesii.net/2009 05 01 Clocher film 800/index.html

The whole digital set is at:
http://www.jonesii.net/2009 05 02 Clocher party/index.html

The last few in the digital set are no flash, hyperfocal Panasonic G1 w/ 25mm 1.5 wollensak cine lens, a fun way to shoot a bit RF 'esque, is that a word?

Dave

 

[dnmtsn]

djonesii, thanks a lot for posting these pics. The ones shot with the fuji look absolutely fine, so I'll feel safe shooting with flash in P mode.

I'd still like to know the answer to my question though, so if anyone els has any thoughts on this...