I am thinking of doing some pinhole macro work.
Looking the internet up I found some interesting thoughts
If you draw a ray diagram you may see a problem if you bring it very close to your subject, and your film sensitivity curve isn’t narrow.
For one thing the material in which the hole is made would need to be very thin, or you’ll get some odd vignetting.
But also remember that pinhole does a very poor job of focusing different wavelengths to the same plane. As the subject gets closer to the pinhole, that issue should get more noticeable: rays containing all the colours will need to approach the pinhole from more extreme angles.
Hence my suggestion to use a film with a narrow sensitivity curve… it’d be best if it were sensitive to a single wavelength
Seems I will have to do some tests myself
Ilford Pan 100 (old): 510-Pyro 1:200 10 min 1min Agitation, 21 C
Ilford delta 400: 510-Pyro 1:100 5 min 1min Agitation, 21C
Ilford FP4+: 510-Pyro 1:100 7,30 min 1min Agitation, 21C
Danie Keating regularly comes up with useful and very interesting ideas of alternative developers. Find him on flickr.
The formulas are as follows—assuming 300ml single reel 35mm tank:
Keating’s T42 Green Tea Phenol Developer
- 300ml tap water room temp
- 4ml 10% solution of sodium hydroxide (lye drain cleaner)
- 0.7g sodium bicarbonate (common baking soda)
- 0.5g ascorbic acid (vitamin C powder)
- 0.25g Green tea Phenol powder
Times will vary with film speed 20 mins to 1 hour semi stand
Keating’s Peppermint Twisted Developer
*Same 300ml assumption
- 300ml room temp tap water
- 2g Sodium Metasilicate (this is sold as TSP/90 wall wash for paint prep at hardware stores)
- 0.7g sodium bicarbonate
- 1g ascorbic acid
- 0.25g dried peppermint extract
40mins-1 hour stand—expect more grain with this formula on higher speed films. Use either formula soon after mixing.
Personally, I prefer the Green Tea version but you may want more grit for street photography. These small footprint formulas solve for the following:
- Less expensive than caffenol. 250G of green tea is $26 and 0.25g per roll means you can realize 1000 rolls at 2.6 cents per roll. Instant coffee is about 30 cents per roll for Caffenol.
- Less consumptive of total weight of chems—far smaller overall footprint or impact on what goes down the drain.
- No exposure to metol or sodium sulfite so contact dermatitis is avoided.
- Nothing has to come from a chemist.
- Image quality looks quite good to me
Another post from Daniel:
same negative Smena MZ3, the whimpy washed out scan was fixed in Kodak Rapid fix. The higher density one was achieved by re-fixing it in Arista non-hardening fixer. These are both raw scans of the same negs from same scanner. Easily a 1.5 stop boost
His pic shows the difference. Interesting.