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night photos

 
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lamplighter



Joined: 07 Nov 2001
Posts: 2
Location: NE USA

PostPosted: Thu Nov 08, 2001 2:04 am    Post subject: Reply with quote

Doing photography with my 4x5 and Nikon N90 I have used 160 VC and just transfer the settings from the 35 to the 4x5. In low light levels I have found the 4x5 negs will be just a very small tad under exposed. Now here is the question that I have asked at camera shows custom labs and repair centers with no real answer. Doing night flash photos you set the Nikon with 160 VC at around f8. The shutter is on bulb and the subject is "painted" with flash bulbs or BIG flash units. The pictures are stunning! Now with the Graflex , same film, same f8 setting, the pictures are at least two stops under exposed. The bellows factor shouldn't come into play at a fifty foot setting? No one can come up with a real water tight answer. Hope some one here can Thanks!
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Kim



Joined: 10 May 2001
Posts: 44
Location: upstate NY

PostPosted: Thu Nov 08, 2001 2:59 am    Post subject: Reply with quote

Is this true regardless of the lens in the speed? Have you ruled out something peculiar to thisparticular lens?


a mystery


good luck

Kim Hartshorn
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lamplighter



Joined: 07 Nov 2001
Posts: 2
Location: NE USA

PostPosted: Thu Nov 08, 2001 3:56 am    Post subject: Reply with quote

No the lens doesn't effect it. I have two Wollensak Graflex 135 lens shutters. The other two MINT cameras have Schnider lens sets with a 135. I would think that f4.5 or f 16 what ever; would be the same from camera to what ever kind of camera. By the way.. I also use polaroid backs for the 3 1/4 x 41/4 film packs. Have you tried the Fugi FP 100 film? This stuff is WOW! It uses a sheet film negative not paper and the little prints will stand up to a 4x loop with very high quality!
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Les



Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI

PostPosted: Thu Nov 08, 2001 1:47 pm    Post subject: Reply with quote

A couple of possiblities, none of which can account for a 2 stop loss, so I guess these explanations have a constant drip.

Had you been using a pre war uncoated Tessar, you could have lost as much as 30% of the light inside the lens from the air to glass surfaces.

But your lenses should be at least single coated which cuts down on that dramatically, plus you're losing 75% of the light somewhere.

Another possiblility is that you've moved the lens to the limits of its coverage. That can cause this amount of light loss but it would be obvious that the loss would form an arc in the neg.

I'm betting either you've got pin holes that let all that light escape before it got to the film, or you've got some cosmic dark matter stuck inside the bellows sucking it up.

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Dan Fromm



Joined: 14 May 2001
Posts: 1892
Location: New Jersey

PostPosted: Thu Nov 08, 2001 7:03 pm    Post subject: Reply with quote

Quote:

On 2001-11-07 18:04, lamplighter wrote:
Doing photography with my 4x5 and Nikon N90 I have used 160 VC and just transfer the settings from the 35 to the 4x5. In low light levels I have found the 4x5 negs will be just a very small tad under exposed. Now here is the question that I have asked at camera shows custom labs and repair centers with no real answer. Doing night flash photos you set the Nikon with 160 VC at around f8. The shutter is on bulb and the subject is "painted" with flash bulbs or BIG flash units. The pictures are stunning! Now with the Graflex , same film, same f8 setting, the pictures are at least two stops under exposed. The bellows factor shouldn't come into play at a fifty foot setting? No one can come up with a real water tight answer. Hope some one here can Thanks!

Not to be a complete idiot, but when you "paint" with the graflex, do you use the shutter to trigger the flash or do you leave the shutter open and fire the flash manually?

Also, WHAT are you using that has an ASA 160 GN of 400 (f/8 @ 50') in feet?

If you have a meter with a "pin point receptor" like my old Minolta Flash Meter (the first one, with no number), you could try metering on the graflex's ground glass and via a piece of ground glass placed on the Nikon's film guides. That would clear up the question of whether the aperture markings or lenses' transmissions are wildly off/different.

Cheers,

Dan
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Les



Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI

PostPosted: Thu Nov 08, 2001 9:24 pm    Post subject: Reply with quote

"Also, WHAT are you using that has an ASA 160
GN of 400 (f/8 @ 50') in feet? "

I'm gonna guess and say 8 pops with a 283 Vivitar would give you a GN of 400 @ iso 160

1pop=110 @ISO 100
2pops=160
4pops=220
8pops=320

8pops @ ISO100 should be pretty close to 400@ISO 160

Now that 8 pops for the same area, so when painting, say a small town theater, and the vivtar will cover maybe 20 linear feet of an 80 foot store front, you are pretty much "poping as fast as you can for about three to five minutes"
while walking the front of the store trying not to backlight yourself or flash the camera.

It's one of those "expose for the secrets, develop for the suprises" parts of photography.

How are you judging the two stop loss? from the prints, the negatives, Polaroid? Is it possible that either the film or the print is being mis-processed?

[ This Message was edited by: Les on 2001-11-08 19:44 ]
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daleraby



Joined: 24 Nov 2001
Posts: 60
Location: Green Bay, Wisconsin

PostPosted: Sun Dec 02, 2001 8:30 pm    Post subject: Reply with quote

Just a couple other possibilities...

Just because the lens barrel is calibrated ton indicate that a certain setting is f/8 does not necessarily mean it is the truth.

Also, 4x5 sheet film is processed differently... i.e.: in a tray or a development tank, whereas roll films might be processed in daylight tanks (at least if you are doing it yourself). This could possibly cause a difference in the results... though not usually two stops. Just for the heck of it, try a little old fashioned "push processing" with Agfa Rodinal (?). You need not worry about grain in this format, though your contrast will be a little harsh.
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