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B Setting seems to stay open

 
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frohnec



Joined: 12 May 2004
Posts: 57
Location: Virginia

PostPosted: Sat Jan 28, 2006 8:23 pm    Post subject: Reply with quote

When the lense of my Speed 127mm is set on B and I trip the shutter it seems to stay open. If the B setting is not operating correctly can I use any other shutter speed say 1/50 and adjust the aperture?
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alecj



Joined: 09 May 2001
Posts: 853
Location: Alabama

PostPosted: Sun Jan 29, 2006 3:32 am    Post subject: Reply with quote

Quote:

On 2006-01-28 12:23, frohnec wrote:
When the lense of my Speed 127mm is set on B and I trip the shutter it seems to stay open. If the B setting is not operating correctly can I use any other shutter speed say 1/50 and adjust the aperture?


I'm sorry but that question doesn't seem to compute! A "B" shutter setting is designed to open the shutter [with the previously set aperture] and keep it open until you release the shutter release. What does that have to do with another shutter speed?

If you are saying your shutter remains open when you set it to B and then release it, then your shutter needs to be adjusted.

I don't think you'll have enough f stops to change to a set speed like 1/50, from a time exposure, and have enough f stops to equal that combination. Is that your question?
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frohnec



Joined: 12 May 2004
Posts: 57
Location: Virginia

PostPosted: Sun Jan 29, 2006 2:15 pm    Post subject: Reply with quote

My goal is to use a flash bulbs.
On the lense there is a "B" setting. Shouldn't I set to the B setting when using a flash bulb?
If yes then the problem I see is that when I set the lense to "B" cock and then push the shutter it remains open. I have to recock the shutter to have it closed.
Does that make sense?
I have tried the shutter at 1/50 and it does fire the flash. At 1/100 the shutter does not fire the flash. I guess I could use the table about flash and aperture settings and calculate the correct aperture.
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alecj



Joined: 09 May 2001
Posts: 853
Location: Alabama

PostPosted: Sun Jan 29, 2006 4:07 pm    Post subject: Reply with quote

Quote:

On 2006-01-29 06:15, frohnec wrote:
My goal is to use a flash bulbs.
On the lense there is a "B" setting. Shouldn't I set to the B setting when using a flash bulb?
If yes then the problem I see is that when I set the lense to "B" cock and then push the shutter it remains open. I have to recock the shutter to have it closed.
Does that make sense?
I have tried the shutter at 1/50 and it does fire the flash. At 1/100 the shutter does not fire the flash. I guess I could use the table about flash and aperture settings and calculate the correct aperture.



OK, now we're on the same page. The problem comes from your misunderstanding of the various features of your shutter.

The B setting is NOT specifically for flashbulbs. It is for timed exposures. From your description, it is working correctly. Check to see if your shutter has a lever where the choices are M and X. If so, the M setting synchronizes the exposure with a flashbulb (and the X synchronizes it with electronic flash).

If your shutter does not have an M-X lever, or does not refer to synchronization on its face, then it may not sync with flashbulbs at all. Which shutter do you have? Even w/o built-in sync, you could use flashbulbs if your camera has a solenoid, because that's what provided flash sync with the early shutters.

The shutter speeds do not primarily affect synchronization, although the faster the speed, there is less light from the flash bulb for the exposure. Your guess about how to determine proper exposure is correct, provided your shutter syncs with flashbulbs.

You really need to do some serious reading on this subject to educate yourself. Look for a copy of Graphic Graflex photography, or copy the Graflite Flash manual which is available online.

[ This Message was edited by: alecj on 2006-01-29 08:09 ]
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frohnec



Joined: 12 May 2004
Posts: 57
Location: Virginia

PostPosted: Sun Jan 29, 2006 5:01 pm    Post subject: Reply with quote

Shamefully I must admit I have a copy, and read each, of the owners manual for the camera and flash.
I thought the B setting was like the settings on SLR's where there is a preset shutter speed associated with the "X" setting.
The best information I found was an article about graflex flash photography http://www.photo.net/photo/speed-graphic.html where it states press photographers use to set the speed at 1/200 use a #5 bulb, set the aperture to 16 and focus at 10'. Now my lense does have synchronize on it and when I tested with a VOM there is a slight movement on the voltage scale (at the bulb fitting)at 1/200. I then tested at 1/50 and the needle moved quite a bit. I plugged a bulb in and sure enough it worked. I will change the opening to 22 and the shutter speed at 1/50.
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alecj



Joined: 09 May 2001
Posts: 853
Location: Alabama

PostPosted: Mon Jan 30, 2006 4:25 am    Post subject: Reply with quote

[quote]
On 2006-01-29 09:01, frohnec wrote:
I'm sorry to differ here, but I don't think your generalization (set one f stop and shutter speed) will work for all situations. For instance, that description is probably based on a film with characteristics you can't replicate. You really need to read more, or talk to someone with more experience. There are correct settings (which vary) for various situations (depending on film, flashbulb type, lens, distance from camera to subject, film developer - just to mention a few). Flash bulbs are not cheap anymore. You'd do better to get proper education rather than attack this by trial and error. With so many variables, I doubt you'll ever get repeatable results this way. Just my 2.
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Henry



Joined: 09 May 2001
Posts: 1439
Location: Allentown, Pennsylvania

PostPosted: Mon Jan 30, 2006 9:16 pm    Post subject: Reply with quote

Forward into the past---time to read up on guide numbers!?

Alternatively, a meter with a flash function.
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