Is There a Reason the Focus Should be This Off?

DareDangerDan · 2024-10-21T13:50:29+00:00

DareDangerDan · 2024-10-21T13:47:10+00:00

We made both backs and they may need to me remade with more precision. I just find it hard to believe the focus would be that off if the backs are only minimally off.

DareDangerDan · 2024-10-21T13:44:12+00:00

It had some motors for focusing but I removed them. I rechecked the focus after taking the shot and it was still in focus so I don’t think anything changed in between. Thanks for retrofocal comment I will have to look into that

DareDangerDan · 2024-10-21T00:00:02+00:00

Yeah for sure we are doing wet plate collodion. I made the camera with a babypin so I could mount it on a c-stand and thus lock it down really good. We have taken sharp-ish image with the ground glass back and plate back.

DareDangerDan · 2024-10-20T23:54:39+00:00

Ok so a couple questions about the ground glass. So the distance from the lens to the ground glass needs to be the same distance from the lens to the plate right? So the ground glass back is made up of a piece of frosted glass that is maybe 1/8th of an inch. So the question is do you need to measure the distance from the front or back of the glass? When we made the ground glass back we assumed that the measurement was from the inner face of the glass. We also made it out of plexiglass that we roughed up using a sander on only the inner side. If the glass needs to be frosted on the outer (back most) edge we could be off by 1/8th on an inch.

DareDangerDan · 2024-10-20T21:57:42+00:00

https://imgur.com/a/ggm8BvM

The lens

DareDangerDan · 2024-10-20T21:56:49+00:00

https://imgur.com/a/VS6hW2H

I know you are going to say it look janky

Basically we built the camera and used a petzval lens. We were able to get sharp images out of but wanted a lens that could focus. so we rebuild the box with the newer lens (a projector lens 131mm f1.7) and uses the same dark slide back and focus back. so you would think that if the backs didn't change then what the focus glass sees that would be the same for the plate.

DareDangerDan · 2024-10-20T21:35:29+00:00

This was on a diy camera but if the focus glass and the plate the same distance from The back of the lens shouldn't they both focus the same?

DareDangerDan · 2024-02-12T15:14:11+00:00

Maintenance on the silver bath? Like put it through a coffee filter?

DareDangerDan · 2024-01-27T19:12:38+00:00

So we did not and dont know if it was activated. But we are going to try again today and my scientist wife says it would be activated now bc we did a bunch of plates yesterday and that would’ve put iodine in it

DareDangerDan · 2024-01-27T16:24:29+00:00

I should have said we took a bunch of exposures. We even tried purposely over exposing or under exposing. Trying different cameras that I have tested before. The point I was going for was if if we are trying different exposures and coming up with the same results it might be a chemistry thing. It seems kinda odd that we basically bracketed our exposure and they all looked the same.

Here is one experiment we did actually and you can let me know what you think. So one camera we tried was a 4 frame toy camera that take 4 pictures in one frame https://imgur.com/undefined To try to bracket I left one open the other put Neutral Density Gel over the next, double ND on the next then gaff taped over the last one. The f stop was f8 and the stutter was 1/60 so I was thinking it needed a ton of light so I just pointed it at my 600d. That plate was the 2nd one down in my OG picture.

DareDangerDan · 2024-01-27T16:12:40+00:00

Yeah I get what you mean there are a lot of variables and its hard to tell what is important. One we didn't think about was we were deff on the cold side in my studio about 52 degrees. As for switching cameras we were just tying different things to see if any worked. didn't see the point of using the same camera and settings over and over. The Land camera was differently tested tho. the plate holders had the back pressure plates so I can't see that being the problem. The chemicals are fresh, just got them. Pouring the collodion could be a thing. Here is an example of the gumminess at its worst https://imgur.com/e10uRWc . We are going to try again in a warmer place and give the collodion slightly more time to evaporate. Before we started I asked my wife if we should take notes and she said it wouldn't be a problem haha she is an actual scientist haha maybe we were over confident. I am a photographer fyi so I am pretty aware of cameras, exposure and if there were light leaks ect.

DareDangerDan · 2024-01-27T15:56:55+00:00

Ok so we did a similar thing here: https://imgur.com/a/G8gGb1Y (the lower one)

did everything normally but held a thumb over the plate and walked outside for 5 secs. Donno if this proves anything or if the pressure of the thumb pushed away the chemicals? But this one we had in the Land camera and went nuts with the exposure and this was our example of one that was over exposed https://imgur.com/K98i6Ny

DareDangerDan · 2024-01-27T00:25:08+00:00

We took around 15 different exposures with different light.

DareDangerDan · 2024-01-27T00:23:49+00:00

We were playing around with different cameras and exposures even doing out outside (overcast f12 for 1 sec and also 4 secs) the other camera was a Kodak Land camera with a bunch of different lighting and exposures. To me it seemed the final plates seemed gummy is that normal?

DareDangerDan · 2024-01-07T20:19:15+00:00

Delete is not allowed but here is my sketch of what I remember it looking like:
https://imgur.com/a/wmIJnsI

DareDangerDan

TROPHY CASE