View Full Version : What caused this "half moon dot" in the attached photo?

24-Apr-2017, 08:25
We were visiting family and my wife wanted a photo of the church where her parents had gotten married.
Strange white anomaly on the roof. Any ideas?

Here's the high res image: https://www.flickr.com/photos/145354246@N05/33432744363/in/dateposted-public/

Dan Fromm
24-Apr-2017, 09:53
Dust on the negative?

24-Apr-2017, 10:45

24-Apr-2017, 11:03
A half moon??

Is there a grade?

24-Apr-2017, 12:49
Cute church! That looks like an apparition to me... specifically a white dove.

Had you not been shooting stills you'd really know that's what it is!


Peter Collins
24-Apr-2017, 13:05
This occurred in order to give you practice in spotting prints.

Keith Pitman
24-Apr-2017, 13:48
Where is that church?

Looks like dust.

24-Apr-2017, 15:12
Where is that church?

Looks like dust.

It's in Centerville SD (southeast corner of the state.)

John Layton
24-Apr-2017, 15:16
pressure from a fingernail stressing the film? hmmm...looks too small. Maybe I'll go with aliens...

24-Apr-2017, 15:19
Does it show on the negative or just the print?

Maybe something in this thread can help

or this one

If it's on the negative, then it's either a stray light source or something interfering with the film development and leaving a dark spot. i doubt it's a light source since it's clearly defined with sharp edges as you point out and a bellows pinhole would be likely be larger and more diffuse. I guess you could always get a defective film negative but that what are the odds of that?

I see on the Flickr site, you're using the new SP-445 tank - any chance something might have been touching against the negative and preventing the chemistry from working?


24-Apr-2017, 18:29
The only time we've seen the SP-445 film holders interfere with processing, is when the negative is loaded in backwards (we've had several customers admit to that.) That leaves very distinct vertical lines if they're using the original holders. Haven't had anyone do it (or admit it to us) with the new holders.

Besides, Tom Wakefield (on the facebook thread) spotted it in another image of mine. I missed it, since it's on the white part of the church.

Neal Chaves
24-Apr-2017, 18:57
I have seen similar half moon-shaped defects on roll film due to crinkling the film when loading the reel, but never on sheet film. As you probably know, stressing the film can cause a build up of extreme density at the site.

24-Apr-2017, 19:37
Are they on the negative Tim?


24-Apr-2017, 20:34
Check the neg carefully to see if there is something stuck to the neg, or a density spot (as this is white, and didn't allow light through the neg there)...

You can also sell the image to the tabloids (or Ripley's) if you come up with a good enough story... ;-)

Steve K

24-Apr-2017, 22:29
Appears to be in the emulsion; part of the image.
No dust, dirt etc.
Might have it on another negative as well.


Are they on the negative Tim?


24-Apr-2017, 23:41
they both appear to be on the same part of the negative. curious... is there any part inside the camera that is shiny and could focus a bit of a flare somewhere?

Peter Collins
25-Apr-2017, 06:30
Well, another thought:

they both appear to be on the same part of the negative. curious... is there any part inside the camera that is shiny and could focus a bit of a flare somewhere?
Both white 'blips'--on the shingles and next to the window--have the same shape and approximately the same orientation. Look at, for example, the upper right side of the blip: something like a curved 'cap' is in this quadrant of the blip.

So I might go back to the camera, check for light leaks, problems with inserting film holders, etc.

25-Apr-2017, 12:05
I think I found the problem: there's a bubble in the lens! Of course, the bubble will move with the movements; so it shifts from one photo to the next. Never noticed this before; I guess you have to aim into the sun just right.

Armin Seeholzer
25-Apr-2017, 13:52
No I do not beliefe your bubble theory, I have also an old lens with 2 bubbles but I didn't see something like this in my negs from this lens! Could it be that a tiny bit sunlight hit the front lens element! Is it a old uncoated lens?

Cheers Armin

Nodda Duma
25-Apr-2017, 14:20
A bubble in the lens is as out of focus as the lens itself. The "aperture" diameter of the bubble is so small that it would be a shadow and not a spot of light. Bubbles in lenses create scatter, reducing contrast ever-so-slightly. They don't, however, create focused spots.

I'd suggest checking for pinholes in your bellows.

25-Apr-2017, 15:25
The bubble in the glass as the culprit, is just as likely as it being one of these...