Always over or underexposed

[dgphoto]

Hi-

Relatively new to pinhole photography.

I use a Holga wide-angle pinhole that has an f-stop of ~128.

It seems like no matter what I do and no matter how I meter, I am always over or underexposed...I've tried using a photo-assistant app that has a pre-set for the Holga wide-angle, I've tried using the rough guidelines printed on the back of the camera, and I've tried a different metering app that I have...none seem to give me consistent results.

Unfortunately I don't have a real light meter.

To further compound my problem, I am headed to the coast in Washington's Olympic National Park in ~2 weeks and don't want to screw this opportunity up!

I currently have 100 TMAX and 400 TriX--unfortunately I missed the boat on loading up on Fuji Acros 100 before it was discontinued in the last year.

I develop film at home so I can test any recommendations prior to my trip.

Thanks in advance for any advice.

David

 

[removedacct1]

Hi-

Relatively new to pinhole photography.

Unfortunately I don't have a real light meter.

David

You say that you have tried metering apps, so I'm puzzled why you still can't nail down exposures. A smart phone with a decent metering app is just as good as a standalone light meter. Have you used Pinhole Assist? (see: https://itunes.apple.com/us/app/pinhole-assist/id466757473?mt=8) I've used it for years and find I can get excellent exposures every time by using it. You do need to set parameters in the meter for the film you're using, and its reciprocity characteristics, and the camera's aperture value, but once you've got that far, the meter is close to foolproof. Is this the metering app you've tried?

 

[MattKing]

With pinhole and a Holga, bracketing is your friend!
An f/128 pinhole probably gets you just into the realm of reciprocity failure, which means that shadows end up with much, much less density then highlights.
T-Max 100 will probably be more dependable when you are dealing with shutter speeds and reciprocity. In bright sun - should you encounter any - Tri-X might lead to inconveniently short and hard to time exposures.

 

[dgphoto]

I am in fact using the Pinhole Assist app--I have 'combos' set for my camera + film combinations....was already out this morning and took a couple of pics and took notes. Will finish and develop the roll this weekend.

I know this app should account for reciprocity failure in its calculations...am keeping my fingers crossed!

Thanks,

David

 

[removedacct1]

I am in fact using the Pinhole Assist app--I have 'combos' set for my camera + film combinations....was already out this morning and took a couple of pics and took notes. Will finish and develop the roll this weekend.

I know this app should account for reciprocity failure in its calculations...am keeping my fingers crossed!

Thanks,

David

Pinhole Assist DOES account for reciprocity, as long as you select a reciprocity adjustment setting for the film you're using. If you don't select a setting, it doesn't apply reciprocity adjustments. The iPhone camera-as-light-meter is a fairly blunt tool, so you have to finesse your metering technique to make the best of it. Its a good idea to find an area in the view that represents approximately middle gray, and get close enough with your phone camera to isolate as much of that value as possible, then take a reading. It may be useful to take a 50% gray card with you and meter off of that. If you have Pinhole Assist and you are using it correctly, then you shouldn't be getting wildly under/overexposed frames. This tells me you may need to review your metering technique and make some changes. Even so, it wouldn't hurt to bracket exposure if you really want to nail it down and guarantee at leats one good frame for each scene you photograph.

Good luck!

 

[darkroommike]

Funny fact, when you get beyond 1 second exposures, Tmax 100 acts faster than Tmax 400 or Tri-X, in that reciprocity departure seems to kick in a bit slower.

 

[Grandpa Ron]

I had the same problem for the first couple of rolls of film. So I finally bought an inexpensive light meter on Ebay for $30.00.
I was using an f 194 aperture 65 mm from the film plane, so I took the reading at f 22 which was 6 stops less and multiplied the shutter time by 64.

I was using Fuji color which seems to have about a 2 stop latitude under normal conditions. Therefore an exposure of 1/60 th of a second at f 22 would be about 1 second at f194. Or, 1/30 th of a secound at f 22 about twice as long.

Once I knew for sure the relative amount of light things got better quicker.

 

[Nick Dvoracek]

Even so, it wouldn't hurt to bracket exposure if you really want to nail it down and guarantee at leats one good frame for each scene you photograph.

Good luck!

Bracketing may be worth it to do once or twice to learn about your film, but with five minute exposures it takes some dedication. Pinhole Assist gets me there pretty consistently.

 

[Grandpa Ron]

The trouble I had with bracketing the exposure was the latitude of the photo printing shop. The CD they returned showed passable photos while the negatives showed a wide range of exposure. A plus or minus 2 f stops bracket was automatically corrected by the CD making machine. Yes you could tell the difference in exposure and color shifts, but they were all usable digital images. A 2 stop bracket on a 3 sec exposure was 1 sec to 12 secs.

Being new to the idea of Pinhole photos I decided to take the easier albeit more costly route of commercial development. I sent in the film and they returned the negatives and a CD of the prints.

My alternate goal was improving resolution, I am after soft focus, not fuzzy focus. I also prefer make my own pinholes and smallest I could get so far is .356 mm (.013). The end result was the 35 mm format needs too much enlargement, which magnifies the fuzzy focus. So now I am restoring a 4x5 view camera, which opens another can of worms, as I will be processing my own b&w cut film.

The view of the Tippecanoe River is about as good as I could do in 35 mm.

 

[dgphoto]

I just finished developing 2 rolls in my wide angle pinhole using the advice several of you have kindly offered...they are still trying but look MUCH better and more consistent. I took notes for every image...some I used just the Pinhole Assist app and for some I also used a grey card I dug out.

Big thanks to everyone!

3 follow up questions did emerge as I did my testing(in the event that anyone is still reading thru this thread):

1. It seems that some of many of my prior underexposed negatives were related to changing light (i.e. usually dusk)--how do you account for this when your meter/app gives you one reading, but by the end of that 10-15 min exposure...the "real" exposure reading it now 37 minutes?

2. I've had some light leaks with this camera and so in an attempt to eliminate that variable this weekend, I covered every seam/edge with tape---including some black tape on the inside as well. A quick scan of the negatives indicates I probably got rid of the thin vertical line artifact/leak I've seen previously, but there is STILL a horizontal line about 1/4 down from the top of the negative...below that line the entire negative is of one density, above that line, the negative seems a bit less dense...this is across ALL negatives...it doesn't matter if it's the bottom reel or the top reel in the canister (which actually always has 2 120 reels and a 35mm reel in it). It also doesn't seem to matter if it's a 2 second exposure or a 5 minute exposure...it's always there.

It's driving me nuts....any thoughts on what the cause is or how to track it down?

3. When I was investigating the problems listed in #2, I looked thru the actual pinhole from both sides...it's super tiny, but I swear there's some sort of subtle mesh that seems to be in the actual pinhole opening...is that normal? Can I gently stick a pin in it? I don't think that's related to the light leak, but was surprised to see anything in the hole.

Thanks again to everyone for their help and advice. I really appreciate it.

David

 

[mcfitz]

Thank you, this is an interesting thread.

I can only reply to your last question based on my own experience. Don't try to stick a pin in the pinhole, there is a chance you will damage it. Don't ask how I know.

Also I suspect there is no mesh. I always see a sort of mesh or lines when I look through a pinhole, and I mostly make my own but have seen it with a laser drilled one too. I've checked them on a light box using a loup: no mesh. I suspect what I see is due to my own vision.

 

[Grandpa Ron]

I have to agree with mcfitz. The mesh like image is not there when you back light with a jeweler's loop. But it sure seems real when held up to a light bulb.

I am sure there is a optical formula to explain it but I prefer t think it is one of the great mysteries of life.

Good Luck

 

[MattKing]

When you see the "mesh", you may actually be seeing diffraction at work.

 

[MattKing]

Reported

 

[Andrew O'Neill]

I use an incident, as well as a spot metre when working with the Holga pinhole wide. It's also the only time I ever use box speed for both films that I stick in it, HP5, and Acros. I don't trust any of those metering apps. Shooting a stop over and a stop under is also a good thing to do.

 

[Andrew O'Neill]

My pinhole wide is f/135.

 

[wiltw]

The bane of photography

• a fluctuating light source
• an inconsistent shutter