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Ramiro Elena
3-Jan-2016, 17:32
Excuse me for not asking this at Graflex.org but I didn't want to register there just to ask a simple question as I know there are very knowledgeable people here too. I am trying to get my Graflex Super D 3 1/4 x 4 1/4 to work with studio strobes.
I wasn't getting the circuit to close as it should so I opened it up and revised the contacts. Finally got it working on Low tension and 0 setting.
Since the curtain is having a hard time doing the whole travel I thought of switching to high tension but I get no contact at all.
Is this normal? I thought you could fire flashes on 0 setting either on High or Low.

If unable to use High tension... any tips on getting the curtain to properly work on Low tension?

I've tried placing a rubber band from one of the ears of the winding knob to the tension knob. I know... :(

LabRat
3-Jan-2016, 18:18
Everything has to move/roll correctly in the FP shutter assy to be able to use low tension/large slit settings... All bearings, roller pivots, etc have to move perfectly freely...

Then check the speeds to see if you have to re-tension the shutter...

Good Luck!!!!

Steve K

mdarnton
3-Jan-2016, 19:41
Yes, it should fire from O at high tension. If it isn't, something is still wrong.

EdSawyer
3-Jan-2016, 20:59
clean the contacts?

Sirius Glass
3-Jan-2016, 21:07
I recall discussions on www.graflex.org about the flakiness with the focal plane shutter firing the flash. Bert Sanders cautioned me not to bother to use it on the two cameras which I bought from him.

mdarnton
3-Jan-2016, 21:22
It seems a pity to give up on a feature that worked well enough for the company to be able to sell it just because someone on the tubes has given up. Try this: http://www.tobiasfeltus.com/site/cameratech/x-synch-on-the-graflex-rb-super-d/

Ramiro Elena
4-Jan-2016, 01:50
I lubricated the gears when I opened the plate. All speeds seem nice and snappy and everything moves freely.
Contacts cleaned.
Now the mystery is why would the flash work on low tension and not in high.

I actually followed Tobias directions and checked everything made good contact. In my case there was a problem between the outside pin an the inner plate. I already solved that.

mdarnton
4-Jan-2016, 05:34
You can wind the tension up in single clicks--it doesn't have to be L or H only. Does it consistently quit at some particular spot in the span of clicks? It might indicate that under tension something is being sprung apart, and shouldn't be.

Jim C.
4-Jan-2016, 12:09
Your problem may be where the tab on the FPS shutter passes over the contacts,
the shutter curtain might be out of square or missing the tab on the curtain.
On lower speeds it 'just' makes contact, higher speeds it floats past the contacts.
You'll have to remove the camera back to see. The fingers on the contacts might
have to be bent a tiny but to make contact with the tab on the curtain

Off topic, but I recently helped a member on Graflex.org with measurements for a
Pacemaker FPS curtain and I noticed that three of the four openings had a tab contact.
Anyone have a clue as to why ?

Jason Greenberg Motamedi
4-Jan-2016, 12:21
Jim C's idea about the contact makes sense to me. I had a 3x4 Super D on which one of the metal curtain-opening frames was bent and wouldn't sent off the shutter at any speed.I bent it back to square and it worked perfectly.

Ramiro Elena
4-Jan-2016, 12:26
I was just discussing this with Tobias Feltus over email. I thought the contact was made inside the winding plate. In fact that's why I opened it in the first place and solved it by adjusting one of the pins which wasn't making contact.
The circuit is closed in L tension and a couple of turns higher, after that it stops.

On the curtain subject, I think I solved it for now. By sliding the Instant/Time lever in the mirror lever forward a little, it pushes the L shape trigger with a bit more strength and the curtain doesn't fail and travels the whole distance everytime.



144476

Ramiro Elena
8-Jan-2016, 07:25
Before I open a new thread on a similar subject, a quick electronic question on radio triggers.
I've gotten the x-sync to work nicely. After initial testing connected to a SB-26 I decided to use my radio triggers. Can anyone explain why it won't work with triggers and it will with a cable?
Is there an electronic explanation to this?

LabRat
8-Jan-2016, 08:25
Yes, there's a reason...

Most strobe trigger circuits have a higher voltage across them, then a radio trigger, so if the flash contacts are less than perfect, the higher voltage has a better chance to go across those contacts...

You can also put a very small flash on camera, and a flash slave on your higher powered strobes to trigger them...

Steve K

Ramiro Elena
8-Jan-2016, 11:29
I would like to avoid using another flash. Specially since Bowens slaves are very weak and sometimes they have a hard time even when another Bowens flash goes off.
Is there anything that can be done between the camera and the trigger to "amplify" (don't know what the correct concept would be) the signal and make the trigger set the receiver off?

LabRat
8-Jan-2016, 19:38
Other than cleaning up your contacts again, not much... Other than using a relay + power supply (where there would be a time lag), or if an engineer could build an electronic relay for you, maybe...

The simple solution is to just have a sync cord long enough from camera to strobe, and not use the wireless sync with this camera...

Good Luck!!!

Steve K

Ramiro Elena
9-Jan-2016, 00:57
Thanks Steve. I've been using the long cable for 20 years. It won't hurt continuing to do so. ��

Ramiro Elena
17-Jan-2016, 15:10
This is one of the test shots I did with the flash sync at low tension. A couple unexpected details, it came out greatly underexposed (measurements were correct) and the catch lights are strange (see detail). This was lit with a translucent umbrella.
My only guess is the FP curtain is actually taking part in the exposure? Is this even possible?

https://farm2.staticflickr.com/1542/24384790446_0dc409fb09_c.jpg (https://flic.kr/p/D9NqDu)
SuperD015 (https://flic.kr/p/D9NqDu) by Ramiro Elena (https://www.flickr.com/photos/rabato/), on Flickr

145239

LabRat
17-Jan-2016, 22:15
Is the flash syncing with the shutter properly??? It looks like it might be recording the ambient light in the studio, and the eye catchlights might be from a distant light or window, etc that are leaving a trail due to eye movement from the longish exposure... The shutter (with sync) is slow enough that it could do that... Or the shutter might not be syncing at the right time, only allowing the afterglow of the flash to expose, but not the full (peak) output...

Look through the back of the camera while firing the strobe, without a lens on it, while looking at a white wall... You should be blinded from the flash you see through it (you can also put a flashmeter or test film on the back)... The camera sync may be set-up for M flashbulbs, where the flash is fired first (to allow the bulb to heat up and reach full output), and then the shutter opens, but now is firing the bulk part of the flash duration before shutter opening, but only recording the afterglow region of the output...

Steve K

Ramiro Elena
18-Jan-2016, 01:38
The room was pitch black so no ambient light possible. The camera doesn't have x/m settings. It is supposed to sync at (I think 1/20 or 1/10). I was under the impression the flash would set the exposure, the FP curtain is just there to open and close for the duration of the flash. I'll check what you mentioned...

mdarnton
18-Jan-2016, 06:06
Did you use the drop shutter setting? That's when the shutter is initially open (set to 0) and the mirror down, and the rising mirror fires the flash to the already-open film, then the second curtain falls. That's the only speed you can use with electronic flash or conventional flash bulbs. ANY other speed setting, such as 1/30 (the lowest speed) will not work. Sync between 1/30 and 1/1000 is intended only for the old giant-size foil-filled focal-plane-shutter bulbs, not even the small #5-sized ones. I haven't seen one of those bulbs in decades.

Ramiro Elena
18-Jan-2016, 06:33
Yes. Unless the "0" speed is actually faster but then I would expect banding. That's what I find puzzling, if the curtain was shortening the exposure the curtain would have to appear in the frame. Am I right?

mdarnton
18-Jan-2016, 06:44
Yes. It wouldn't have an effect over the whole photo--you'd see a line somewhere, and everything on one side of that line would be different from everything on the other side.

Have you tried the test of opening the back of the camera, no film holder, and firing the flash with the shutter as normal, looking to see if you can see the flash go off through the back? Point them both at a wall and look for the bright flash through the back of the lens. If you see it, good; if not, bad.