[n333ms]

I'm a proud new owner of a Pentax 645 camera. The set up I have is very clean and in excellent condition. Last week I took my first test roll of Kodak Portra 400 and did various shots, however when I recieved my negatives only the first 10 photos showed up on the negative, the following 5 negatives were completley transparent and did not register. The numbers on the edge of the roll came up, however the photos did not. Now I'm just trying to eliminate some of the variables that might have caused this issue. The place I took to develop the film was horrible, (it was my only choice where I am, I usually mail in my film). My first thougt was that the lab might have screwed up, but I'm not positive if that's the case. My other thought was that maybe it was a battery issue in loading to the next exposure, but I feel like that's also unlikely because after the whole role was shot the camera automatically wound the film correctly. The last 5 shots I took, where done indoors at night with +3EF, according to my light meter it should have been ok, but there is the chance that the shots were blown out. I'm not new to film, I'm just new to this camera and want to make sure everything checks out.

Any thoughts?

[barondla]

I'm a proud new owner of a Pentax 645 camera. The set up I have is very clean and in excellent condition. Last week I took my first test roll of Kodak Portra 400 and did various shots, however when I recieved my negatives only the first 10 photos showed up on the negative, the following 5 negatives were completley transparent and did not register. The numbers on the edge of the roll came up, however the photos did not. Now I'm just trying to eliminate some of the variables that might have caused this issue. The place I took to develop the film was horrible, (it was my only choice where I am, I usually mail in my film). My first thougt was that the lab might have screwed up, but I'm not positive if that's the case. My other thought was that maybe it was a battery issue in loading to the next exposure, but I feel like that's also unlikely because after the whole role was shot the camera automatically wound the film correctly. The last 5 shots I took, where done indoors at night with +3EF, according to my light meter it should have been ok, but there is the chance that the shots were blown out. I'm not new to film, I'm just new to this camera and want to make sure everything checks out.

Any thoughts?

Congrats on the 645! 120 film is great. There is a learning curve.

Three things point to it NOT being the lab's fault.
1. Some of the photos came out fine.
2. All the info Kodak exposed on the negative edges is fine.

So the film was properly developed thru the whole roll. If the lab had messed up developing part way into the film, the "exposed by Kodak" edge info would be as transparent as the matching images.

3. Bad images are clear. This means light didn’t reach the film. If the lab screwed up and exposed the film to light, the images would be dark.

So the clues point to you or the camera/lens. If camera, the shutter didn’t open or perhaps the lens aperture went to a very small hole like F22 or 32. If it's operator error, you didn't remove the lens cap, meter correctly, or something else.

Good luck,
barondla

[n333ms]

Thank you!

I'm guessing being on f22 might have been the case. I've check the camera and everything seems to check out ok mechanically. Odds are it was user error. The last shots I shot were all indoors under poor lighting conditions. I'll find out with future rolls!

[barondla]

Thank you!

I'm guessing being on f22 might have been the case. I've check the camera and everything seems to check out ok mechanically. Odds are it was user error. The last shots I shot were all indoors under poor lighting conditions. I'll find out with future rolls!

If the lens has an aperture ring, with an A setting, it might have been accidentally moved off A. I've done that before changing lenses.

Thanks,
barondla

[tuco]

A frame with only base + fog density means no exposure. And if there were any highlights in those 'blank' frames, I'd say that would be unusual for f22 to place the brightest highlight in the picture below zone 1 density if the scene was metered well.

[Alex645]

I'm guessing being on f22 might have been the case. I've check the camera and everything seems to check out ok mechanically. Odds are it was user error. The last shots I shot were all indoors under poor lighting conditions. I'll find out with future rolls!

Yes with the edge numbering being consistent, it's not the lab. 400 ISO neg films are fairly forgiving, but f/22 @ indoors at night without a flash undoubtedly led to underexposure and a blank/clear negative. For that to work, you'd need a fairly long exposure around 6 seconds (bulb) on a tripod.

[RICHARD L.]

Always write down your exposure parameters and check the quality of your resulting images. Best way to learn and acquire experience.

Regards

[tuco]

Some thoughts.

Let's say your indoor metered exposure was f8 at 1-second (the middle gray exposure) for 400 film. And you can capture 10-stops of light. The bright lights in the room would be 5-stops above the middle gray and deep shadows 4-stops below. Call each of the 10-stops of light a 'zone' for talking purposes. Zones 1 (first hint of recored density) through zone 10 (bright no more detail). The unexposed areas between the frames would be the film's base + fog density (zone 0)

Now if you took the picture at f22 @ 1-second instead of f8 @ 1-second, that is a reduction of 3-stops of light. A zone 10 density would move down to zone 7. You would be under exposed but you'd still see plenty of recored density on the negative. Holding the shutter speed fixed at 1-second, you would need to stop-down 10 stops of light to move a zone 10 density down to zone 0. That's a lot and there are not enough aperture range.

But if, say, you accidentally had the camera at 1/1000 of a shutter speed instead of 1-second at f8, that would place your highlights 10-stops lower into the base + fog density creating a completely blank image. So the error from a well metered scene needs to be big to create a completely blank negative. Another 10-stop error combo would be f22 @ 1/125 in lieu of f8 @ 1-sec.

[Alex645]

Thank you!

I'm guessing being on f22 might have been the case. I've check the camera and everything seems to check out ok mechanically. The last shots I shot were all indoors under poor lighting conditions.

f/22 @ indoors at night without a flash undoubtedly led to underexposure and a blank/clear negative. For that to work, you'd need a fairly long exposure around 6 seconds (bulb) on a tripod.

you can capture 10-stops of light. So the error from a well metered scene needs to be big to create a completely blank negative. Another 10-stop error combo would be f22 @ 1/125 in lieu of f8 @ 1-sec.

Using the Black Cat extended range exposure guide, an interior room with medium lighting at EI 400 and f/22 is a 6 second exposure. If we give Kodak Portra a +/-10EV exposure latitude with perhaps +6EV and -4EV for anything other than zones 0 or 10, at f/22 any exposure shorter/faster than 1/4" would render a blank negative.

The mystery to me in all the info given, is that the OP states that the meter said he had +3EF and that his meter said it would give him a normal exposure.

[tuco]

Using the Black Cat extended range exposure guide, an interior room with medium lighting at EI 400 and f/22 is a 6 second exposure. If we give Kodak Portra a +/-10EV exposure latitude with perhaps +6EV and -4EV for anything other than zones 0 or 10, at f/22 any exposure shorter/faster than 1/4" would render a blank negative.

Sure. f8 @ 1 sec = f22 @ 8 seconds. Hardly any difference from f22 @ 6 seconds. 1/4 second is is only 5 stops difference from 8 seconds. If f22 @ 6 or 8 seconds places a highlight at zone 10, 5 stops will only drop that highlight to zone 5 (middle gray). Yes you have an under exposed negative but you will see and can measure density greater than base + fog.

[Alex645]

If f22 @ 6 or 8 seconds places a highlight at zone 10, 5 stops will only drop that highlight to zone 5 (middle gray). Yes you have an under exposed negative but you will see and can measure density greater than base + fog.

Yes, true....if the OP had a highlight at zone 10 in the shot. Indoors at night without flash, it's possible the brightest highlight was zone 9 or lower.