Pinhole, and gel filter

[Ozzietx]

I have just begun to re-embrace pinhole photography after a 30 year break.
I shot some images earlier this weeks, and have a question.
The first image I shot without a filter, and am happy with the resolution.
The second image I taped a wratten 25 gel in front of the pinhole, and it appears that the image is a little softer.
Could this be due to the filter?

If it matters, this was Ilford Delta 100 shot at 100 iso developed in Xtol 1:1 for 9 minutes at 68.
The first image was in shadow, with an exposure of 28 sec. No filter
The second image was shot in early morning light for 21 sec. with the 25 filter
The camera is a lensless 4x5

 

[Mainecoonmaniac]

I've always had problems Wratten filters. They scratch easily and require a special filter holder. Here's on made of glass. You could buy the smallest one since it's a pinhole camera.

https://www.bhphotovideo.com/c/prod...k9pcp8MJIUYEQA6_vaz8GvsKhHVF5Zy4aAnhEEALw_wcB

 

[dasBlute]

Nice images! I have yellow glass filter taped to the front of mine, keep it up lad, pinhole is a noble method

 

[DWThomas]

It occurs to me that the wavelength of light is one of the parameters used in calculating an optimum pinhole diameter. Typical calculations use about a mid-spectrum value (550 nm "green"), so in theory the result might be off a bit for red light. No idea if it could account for what you're seeing. A Grande Experiment(tm) would be to try a transparent "lens protector" sort of filter in place of the red to see what happens. If similar effects appear it's likely the two surfaces and section of non-air medium rather than a specific color.

But then pinholery is supposed to be mystical!

 

[MattKing]

One of the characteristics of pinhole cameras that makes them so fascinating is how much depth of field they offer.
That includes anything in or on the surface of a filter - it can form a part of your image.

 

[Ozzietx]

Thanks for the feedback. I will do some more experimenting.

 

[narsuitus]

Was the camera on a sturdy tripod? Could there have been camera movement on the second shot?

How did you set the pinhole to film plane distance for the two images?

How did you digitize the images?

Love the Alamo image.

 

[Ozzietx]

Narsuitus,

It was on a pretty stable Carbon tripod, and there was no wind. I really don't think it was movement.
I did not set the film plane to pinhole distance. It is pre-defined by the camera, if I understand your question.
I hadn't thought about the film in the scanner. That is something I need to research. I am using a V700 and the not so rigid film holders that come with it.
I have ordered a betterscanning film holder. Maybe I should wait until that arrives to make a judgement. The images both look sharp through a loupe, but
I have brain challenges looking at negatives sometimes with a loupe.
Thanks for the compliment. I am fortunate to live in a photogenic city.