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A Christmas Cookie from Santa

Interestingly enough, none of the other texts I have been able to get show photos made with any of the emulsions. Mine will probably be a first where I show the emulsion formula, the grains, the sensitometry, the spectral sensitivity, and then show pictures compared to a commercial product.

PE
 
I think that will be new and unique.

What do you see as the difference between the DIY product and the commercial product?
Do such products have no meaningful commercial edge?

I would think Ilford and others need as much support as they can get,
if we want them to be around much longer....
 
Ray;

Commercial products have the potential for much higher overall quality. About 10% of all hand coatings using doctor blades usually have some defect of some sort, the remainder being of production quality. The defects can vary from small pinholes (retouchable) to non-uniform areas (non-retoucahble). Some are there but cannot be seen in the print. So, variability might be the bottom line here differentiating home coatings from production coatings.

You must remember though that Jim Browning made production quality coatings at home, albeit with a pricey machine, but it did work and did give excellent 30x40 sheets. And, we walked into his darkroom, started things up, melted gelatin and made a perfect film coating the first time. We did the same with paper after a day of experimentation as well.

So, high quality is possible.

PE
 
I know.

But on the other hand, Jim ended up selling the machine to PF.
The machine appears not to have been put to much use,
and might even be up for sale again,
judging from posts I have seen on apug.

(BTW anyone know if there was a second or third commercial coating?
Jim mentioned it was about time in 2008 or so IIRC)
 
Ray;

You are missing a point here.

A device that works on a personal basis will still work on a commercial basis, but if you consider the latter, you must consider the costs involved and the profits involved. In other words, the danged thing better pay off! If it is too labor intensive in a down market this does not mean it is a "bad machine" or even "up for sale". That is not for me to say anyhow. What I am saying is that it works but even so, the market may not exist at the current price/cost ratio. Just consider the cost of Silver Nitrate today!

PE
 
What sort of problems might be present in a print that cannot be seen and why should it be of concern if it is not actually visable?
 
Well, I'll give you another specific example anyhow.

For production, you need LOTS of drying space to make a run worthwhile. For personal space you may need to only dry 1 or a dozen sheets. Drying space takes space that is dust, lint and chemical free and DARK for several hours. I can do that hands down here at home for my own needs of about 1 to 20 sheets per run, but doing it for 100 sheets or more would present me with a problem. Doing it for huge production type runs in large sheets would be a REAL problem!

And, it would have to be economical if you were to make any profit.

PE
 
Sirius Glass said:
Photographs will examples of common mistakes would let the user realized that they are not alone and headed toward the right path.

Steve
Click to expand...

Steve:

Photographs of good coatings would be betterI think. If yours doesn't look like that, something's wrong. Besides, Ron's book wil lhave something no other emulsion book has ever had, pictures of emulsions.

Joe
 
$22/10g here.. about 3x the cost of raw silver, over twice the cost as above ;(

Anyway, possible to dry quicker with an infrared lamp or circulated air?
 
Athiril, any of that is possible as long as you have the space! That is critical. And it must be dark, dust free and lint free. So, assume that I coat 100 sheets of 30x40 film or paper, now where to put it and how high can I stack it. Well, it would stack from floor to ceiling in a 10 foot high room leaving about 1" between sheets for air to circulate. That isn't enough!

You guys are not thinking PRODUCTION and are not thinking PROFIT. You are thinking home DR work. Yeah, I can modify a room at great expense, make maybe 20 - 50 sheets at a time and hand cut them. Then I sell them for $1 / sheet and take a loss of about $10 / sheet in costs and labor.

PE
 
Given your other thread.. I was thinking 120 and 35mm (or even 16mm/S16mm). If it can dry quickly enough to be moved slowly and be collected onto a reel.

Friend bought a Super America 35 a while back and I was impressed with it enough to want one too.
 
I'll leave the coating of anything narrower than 120 to someone else. I may not even get into 120. IDK yet as the support supply is not huge, at least for me.

PE
 
IIRC it's available off alibaba.. in huge quantity though. Same from Lucky Film, you can get bopet and acetate film
 
Well, I'll make the point more strongly then!

Since defects go up rapidly as the format becomes smaller, I will limit myself to what can be coated in the home darkroom. I have already determined that 4x5 can be coated with good results wrt defect rate, and I may also run the test on 120, but knowing the difficulties inherent in coating anything narrower, I will not be doing it. That leaves out 35mm, 16mm and 8mm!

PE
 
couldnt you just cut down a larger format though?
 
I think you missed the point. A tiny dust speck on a 4x5 is a boulder in 35mm! The size of the format is what counts. In addition, the sheet sizes use a different thickness support than 120 and 35mm.

PE
 
But you have lower number of those defects per frame when the frame is smaller .

Some people think that their image is wasted if there is a single dust speck or defect, regardless of its size. So, they would have higher probability of a "good" frame when the frame is smaller ;D.

Personally, defects don't bother me that much.

I had a defect in my first coating that was a 35 mm frame. It was a pinhole about 4 mm in size in the final 8x10" print. If it was a 6x7 frame, I might have four defects 2 mm each (again in a 8x10" print), or 4x5" coating might have seven defects 1,2 mm each. OTOH, bigger formats are often enlarged more and people expect more from them, quickly rendering the defects almost as annoying as in smaller formats IMHO.
 
Interesting. I find that smaller formats are more often enlarged, but the enlargement at a proper viewing distance is about the same as perceived. In other words, I may make an 8x10 and hold it at arms length, but I mount a 16x20 on the wall and view it such that the image subtends the same viewing angle as the hand held 8x10.

OTOH, if almost every frame has one or more defect, and if you enlarge every 35, but only contact print your 8x10s then the 35 will appear worse.

PE
 
Far better than the project shot on Super 16mm where there was a hair in the gate at the very top, only a small part of the frame...but can you imagine fixing every single frame as opposed to a single photo? :/
 
I'm afraid that what you would actually get is a whole roll of 35mm (or smaller) in which just about each frame was peppered with tiny random defects. Some of these would be due to the length of film to be coated. That is why I would also omit 220 film from my efforts.

I think it fair to say that I have tried it and it is very difficult to get defect free coatings and the defects become more apparent as the size of the film becomes smaller.

PE
 
Just an update.

A trial run of the DVD is being made on Monday of next week. I am having 20 sets made for evaluation by those of our GEH lunch group who wish to test it. I just signed off on the covers and disk labels.

Still working on the book though, but I have run tests on the new mixer for making larger batches of emulsions or better batches of smaller ones.

PE
 
Congratulations - that's certainly a landmark in your project! Keep up the great work!

Kirk
 
I echo Kirk's comments and am looking forward to the book and DVD.

Joe
 
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