Prints appearing half black -- why?

GrahamATX · May 29, 2011

Hello, I'm fairly to the world of photography and film photography especially. I dug up my dad's old Pentax K1000 SE, which is most likely about 25 years or more old. I shot a roll of film with it, and took it to my pharmacy to develop it (as I'm not ready to develop my own film yet... it'd be nice to get tips on that too) to confirm that it still worked. Sure enough, some of the shots turned out great but at least 10 or so out of the 25 exposures were half-black, rendering them useless. I'm curious as to whether this was the store at fault (which I doubt), the camera, or myself. The camera is completely manual, so I was wondering if this had to with where I had the f-stop or something of the like. If anyone can explain to me the root cause I would greatly appreciate it.

However, as you can see below, when it works, it's pretty good

compur · May 29, 2011

Nice photo.

Post one of the half black photos and maybe we can tell you what the problem is.
Most likely a shutter glitch. Did you use flash with the half black photos?

Josh66 · May 29, 2011

Two things could have happened...

Sticky shutter, or you exceeded the x-sync speed using flash.

If you were not using flash, I would say there is a good chance you have a sticky shutter.

Next time the camera is empty, open the back and look for a gummy residue on the shutter (look at the front too). If you see some, it's the foam breaking down. Replacing the foam would be a good idea, but you have to get that crap off of the shutter too. What I have done is very carefully clean it off with cotton swabs and alcohol.

Then, fire off a few frames and repeat. (With the camera empty...)

If there is no sticky stuff on the shutter and you weren't using flash - I don't really know what else it could be, but I doubt it's something the lab did.

How do the negatives look? (That should tell you if it's the lab or the camera.)

GrahamATX · May 29, 2011

Thanks for the responses. I didn't purchase any copies of the screwed up pictures, but I took a picture of the negatives:

Since they are also messed up, I'm guessing it's what you said about the sticky shutter. I'll look into that. I appreciate the help!

Here's a picture of the camera as well if anyone cares to check it out:

flea77 · May 29, 2011

I'm betting flash sync was wrong.

Allan

GrahamATX · May 29, 2011

Is there anything I can do to adjust the flash sync?

STM · May 29, 2011

GrahamATX said:
Hello, I'm fairly to the world of photography and film photography especially. I dug up my dad's old Pentax K1000 SE, which is most likely about 25 years or more old. I shot a roll of film with it, and took it to my pharmacy to develop it (as I'm not ready to develop my own film yet... it'd be nice to get tips on that too) to confirm that it still worked. Sure enough, some of the shots turned out great but at least 10 or so out of the 25 exposures were half-black, rendering them useless. I'm curious as to whether this was the store at fault (which I doubt), the camera, or myself. The camera is completely manual, so I was wondering if this had to with where I had the f-stop or something of the like. If anyone can explain to me the root cause I would greatly appreciate it.

However, as you can see below, when it works, it's pretty good

The K1000 is a pretty old camera and it is not unusual for a camera of that vintage to have shutter curtain problems. I suspect that is what it is, unless you are talking about photos taken with flash and you exceeded the max synch speed. All it probably needs is a good CLA and I am sure it will go back to taking great photos.

Helen B · May 29, 2011

It looks very much like you had the shutter speed set higher than the flash sync speed (1/60?). This leads to the partial underexposure of the frame (it's part underexposed, not part blank)

Best,
Helen

Josh66 · May 29, 2011

flea77 said:
I'm betting flash sync was wrong.

Allan

After seeing the negs, I agree.

GrahamATX, notice how the dark half still has somewhat of an image on it? If it were a sticky shutter, that half would be totally blank.

GrahamATX said:
Is there anything I can do to adjust the flash sync?

No - it is a physical limitation of the camera, there is nothing you can do to change it. It is the fastest shutter speed that both curtains are fully open.

Just make sure that when you're using flash your shutter speed is always longer than or equal to the max sync speed.

Josh66 · May 29, 2011

Just to add... I would still have a look at the shutter. In this case, I am certain that it was due to the x-sync speed - but, all foams break down eventually. It's only a matter of time.

If you ever notice a sticky residue on the shutter, it's time to replace the foam.

compur · May 30, 2011

The flash sync speed of a K-1000 is 1/60.

That means when using flash the shutter speed must be set at "60" or slower ("30", etc)

If you set it at a higher speed you will get partially blacked out negatives.

Big Mike · May 30, 2011

I agree...my vote is on a flash sync issue with too fast of a shutter speed.

This happens because of the design of the shutter, it's made up of two separate curtains. The first one opens, the second one follows it to close the shutter. The faster the shutter speed, the sooner the second one follows the first. The max sync speed of the camera, is the fastest (shortest) shutter speed at which the entire frame is open. Any faster, and the second curtain starts moving before the first curtain is fully open. So at very fast shutter speeds, the second curtain follows the first very closely...only exposing the film via a little strip of light before them.

This is important when we start using flash. The burst of light from the flash is very short...probably much faster (shorter) than the actual shutter speed. So if the flash fires when the shutter is not fully open, the part of the frame that is still covered by the shutter, won't get any of the light from the flash....so you end up with dark or black blocks in your photos.

Paul Ron · May 30, 2011

The black part has image in it, that might be an advancing problem. Count the frames? Overlapping images? No frame spacing?

EDIT:.... Another thing I just noticed is every other frame is black. advancing problem or sticking mirror? .. another symptom of seals gummy or rotting.... this camera needs service one way or another.

Most times a sync problem at fast shutter speeds will show up as a bar, not half black.since the 2 shutter curtains are flying by as a slit of varying widths getting smller as the speeds get faster. Below 1/60th it makes no difference, all shots will be perfectly fine.

So, it may be a lagging shutter curtain or an advancing problem or mirror sticking in the up position dropping afdter every other shot. The Pentax shutter curtain ribons tend to rot over time n eventually let go. The advancing and lazy curtains are early indicators of this problem. Have the camera over hauled for about $90. There are plenty of guys online that do this work cheap, just google em. Once over hauled that camera will work like a race car for another 30 years of relaiable service.

Josh66 · May 30, 2011

Paul Ron said:
.... or sticking mirror?

It can't be the mirror, since the 'bar' is vertical. Does the shutter travel horizontally on the K1000? I assumed that it did after seeing the negatives, but I'm not sure...