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#1
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Could someone please explain this?
Two cameras...both with the same film, from the same lot numbers. developed
at the same time in the same tank with the same chemicals. the difference is, one came out fine, the othe came out as if way underexposed. the scenario: one camera was a nikon fe-2 with a 105mm 2.5 lens. these are the pics that came out fine. the other camera was an older pentax spotmatic with a 55mm 1.8 lens. this camera yielded the softer results. now, these were also done with a studio lighting setup, so there was no difference in lighting conditions. now that i am typing this, i can only think of one thing. the spotmatic had two pc connections on it. i used the top one. i don't have an old manual for this camera, so maybe it was synced differently or something. i still don't know how that would explain the overall underexposed look. the lens also has a manual/auto slider that may have been in auto, instead of manual. would that have mattered? the lens looks fine. it is very clear. i doubt that it is the problem. the flash sync speed was only 1/60 of a second on it, but i don't know how a slower sync speed could account for underexposure. you'd think the opposite. any help would be great..... |
#2
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Could someone please explain this?
"joe mama" wrote in message ... Two cameras...both with the same film, from the same lot numbers. developed at the same time in the same tank with the same chemicals. the difference is, one came out fine, the othe came out as if way underexposed. okay, i just happened to find an online manual that says the flash sync i used wa a p sync, and the other one was the x sync. what would have made these underexpose? |
#3
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Could someone please explain this?
joe mama wrote: "joe mama" wrote in message ... Two cameras...both with the same film, from the same lot numbers. developed at the same time in the same tank with the same chemicals. the difference is, one came out fine, the othe came out as if way underexposed. okay, i just happened to find an online manual that says the flash sync i used wa a p sync, and the other one was the x sync. what would have made these underexpose? The manual should have said what each sync does with the exposure. You didn't say what shutter speed setting you used and what mode (manual, program, etc) you set the flash, because the timing of the flash with the shutter is the difference. I'm not familar with Nikon, only relating my experience with Minolta, but try it again with identical settings, or without flashes, and you should be the same and equal results. Good luck. |
#4
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Could someone please explain this?
"joe mama" wrote in message
... Two cameras...both with the same film, from the same lot numbers. developed at the same time in the same tank with the same chemicals. the difference is, one came out fine, the othe came out as if way underexposed. the scenario: one camera was a nikon fe-2 with a 105mm 2.5 lens. these are the pics that came out fine. the other camera was an older pentax spotmatic with a 55mm 1.8 lens. this camera yielded the softer results. now, these were also done with a studio lighting setup, so there was no difference in lighting conditions. now that i am typing this, i can only think of one thing. the spotmatic had two pc connections on it. i used the top one. i don't have an old manual for this camera, so maybe it was synced differently or something. i still don't know how that would explain the overall underexposed look. If your lighting is electronic flash, you you need to use the X sync. socket. If it's flash bulb, you need to use the B sync. socket (there's also an FP type, but we won't go into that now, especially as it isn't relevant to the two sockets on the Spotmatic anyway.) Electronic flash fires almost immediately it is triggered - a delay of microseconds. Flash bulbs take longer - a few milliseconds - to reach full brightness after they are fired. So there are two sorts of flash synchronisation provided: X, for electronic flash, fires the flash as the shutter is wide open; B, for bulbs, fires the flash a fraction nefore the shutter is open to give the light time to reach full intensity before the shutter opens. So: if you used the B sync. socket with electronic flash, the flash will have fired and been finished fractionally _before_ the shutter opens. Hence your grossly underexposed pictures. the lens also has a manual/auto slider that may have been in auto, instead of manual. would that have mattered? No, that just sets whether the aperture is kept wide open until you press the shutter release, then stopping down to the set aperture for the exposure and opening again after (auto) or stays stopped down at the set aperture the whole time (manual). Won't alter what the aperture is _at the moment of exposure_, only what you see through the viewfinder. the lens looks fine. it is very clear. i doubt that it is the problem. the flash sync speed was only 1/60 of a second on it, but i don't know how a slower sync speed could account for underexposure. you'd think the opposite. In this case, since using the B sync. with electronic flash means that the flash fires before the shutter opens, using a slower shutter speed makes no difference at all. If things are the other way round - using X sync. with flashbulbs - then a longer shutter speed does mean that the bulb has time to reach full intensity: you may even get a little more light as you are getting the lead in and tail of the flash that normally are cut off. But as the Spotmatic's top sync. speed is 1/60, you'd need to be at 1/30 or less to use bulb flash with the X sync. any help would be great..... Hope that made some sense, Peter |
#5
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Could someone please explain this?
The top terminal is the "FP" synch intended for "FP" Flash BULBs (which
synch up to 1/1000th of a second on the Spotmatic.) Play it safe. Use the X terminal (bottom one). The Auto setting on the Pentax lens is irrelevant. It simply allows you to focus wide open, and the aperture closes when the shutter is tripped. |
#6
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Could someone please explain this?
"Bandicoot" wrote
[...] If it's flash bulb, you need to use the B sync. socket (there's also an FP type, but we won't go into that now, especially as it isn't relevant to the two sockets on the Spotmatic anyway.) It would seem to be relevant to the Pentax Spotmatic. The top socket is explicitly labeled an FP synch on that camera. At least mine was. However, at 1/60th of a second mine synched to either the FP or electronic flash socket. (Not to M bulbs, however.) So, maybe Pentax got it wrong? |
#7
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Could someone please explain this?
"j" wrote in message ... "Bandicoot" wrote [...] If it's flash bulb, you need to use the B sync. socket (there's also an FP type, but we won't go into that now, especially as it isn't relevant to the two sockets on the Spotmatic anyway.) It would seem to be relevant to the Pentax Spotmatic. The top socket is explicitly labeled an FP synch on that camera. At least mine was. However, at 1/60th of a second mine synched to either the FP or electronic flash socket. (Not to M bulbs, however.) So, maybe Pentax got it wrong? Class FP flash bulbs are intended for Focal Plane shutters. The bulb is designed so that the flash duration is extended for long enough, and the output over that time uniform enough, for use with focal plane shutters provided the shutter is operating within certain limits. Most Class FP bulbs require the same delay as a Class M bulb; 20 milliseconds. Because the total travel time for the shutter on a miniature camera is fairly short FP bulbs offer the use of flash over most of the shutter's speed range (varies with the camera). Since all flash bulbs require some time to come up to full brightness synchronizers fire them before the shutter is tripped. Class X synch is for strobe flash. The flash is triggered when the shutter just reaches fully open. For a focal plane shutter the speeds are limited to those where the shutter aperture exposes the entire frame. For older 35mm cameras this is typically 1/60th second. At higher speeds the shutter exposes only a slit of varying width so only a part of the frame will be exposed by the strobe. When bulb synch is used with a strobe the flash is set off well before the shutter opens regardless of the shutter speed. When strobe synch is used with bulbs the bulb will be fired late so there will be reduced or no exposure depending on shutter speed unless a very slow speed is used. FWIW, there are several classes of flash synch: Class F (Fast), 5 milliseconds (miniature and gass filled bulbs). These could be used in simple cameras with long shutter speeds and simple, non-delayed synch. Class M (Medium), 20 milliseconds (most older bulbs) Class FP (Focal Plane), 20 millisecond delay but long duration for focal plane shutters Class S (Slow), more than 20 millisecond delay. These were very large bulbs meant to be used open flash (wihtout a synchronizer) in studio reflectors. -- --- Richard Knoppow Los Angeles, CA, USA There are also other bulb types, flash cubes, etc. |
#8
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Could someone please explain this?
Richard Knoppow spake thus:
FWIW, there are several classes of flash synch: Class F (Fast), 5 milliseconds (miniature and gass filled bulbs). These could be used in simple cameras with long shutter speeds and simple, non-delayed synch. Class M (Medium), 20 milliseconds (most older bulbs) Class FP (Focal Plane), 20 millisecond delay but long duration for focal plane shutters Class S (Slow), more than 20 millisecond delay. These were very large bulbs meant to be used open flash (wihtout a synchronizer) in studio reflectors. So what kind of synch was used for flash pans? (You youngsters may know them only from old movies.) -- In order to embark on a new course, the only one that will solve the problem: negotiations and peace with the Palestinians, the Lebanese, the Syrians. And: with Hamas and Hizbullah. Because it's only with enemies that one makes peace. - Uri Avnery, Israeli writer and peace activist with Gush Shalom. (http://counterpunch.org/avnery08032006.html) |
#9
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Could someone please explain this?
"David Nebenzahl" wrote in message .com... So what kind of synch was used for flash pans? (You youngsters may know them only from old movies.) You mean your new digital SLR doesn't have a, "gunpowder synch" setting? |
#10
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Could someone please explain this?
You mean your new digital SLR doesn't have a, "gunpowder synch" setting? No but it can be connected to the George Foreman USB grill !! {;) == John S. Douglas Photographer & Webmaster Legacy-photo.com - Xs750.net |
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