Something Wrong

[Bingtan]

Hi everyone,

I haven’t been here in awhile as I was working on everything else to make an image and finally, today was that day.

I’m all the way out in the Philippines and have done this only through the help of this community. That said, wanted to ask for your help w my image. It’s coming out really pale. here’s what I initially did:

1) Using the suggestions of putting the iodine in silica gel, I made my first fume at 3 mins.
2) Bromine, also in silica gel, I fumed for 1 min.
3) Shine a bit of light to have a look at things…
4) Another fuming with iodine for about 45 secs.

exposure was at f/2.8 30 secs using a 6×6

5) developing w mercury at 80C

Also, I’m wondering, how long does it take to exhaust a box of iodine fume (500 grams silica gel / 125 grams iodine) – I wonder if I exhausted it as this was my 3rd try in a span of about 2 hours.

Thanks again,

Bing

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[photolytic]

Since you diluted your iodine in silica gel it is harder to measure (by weight) how much iodine you have left.
You could titrate a sample with thiosulfate solution using starch indicator to find out what is left.
However using the measurements of coating thickness published by Pobboravsky (1971 thesis) and a little chemical stoichiometry you can calculate that even after the heaviest fuming (400seconds), a 200nm coating of silver iodide on a wholeplate contains less than 25mg of iodine.
Therefore it is extremely unlikely that you have exhausted the iodine in your box. A low fuming temp (<20C) also seems equally unlikely given your location in the Philippines.
You don’t mention the brightness of the light on your subject but an exposure time of 30 sec @f2.8 is more typical for an iodized plate with no bromine. Perhaps you are low on bromine.
Also it is possible that you overexposed and underdeveloped your plate. You don’t mention the time over the mercury.

[Mike Robinson]

Hi Bing,
Its hard to figure out what’s wrong with the photograph you send. Try copying your image through a small hole cut in a black card. If your plate really looks like that while reflecting dark, then it seems to me very over-exposed assuming the rest of your process is on track. I agree with John, If you are using bromine your exposures should be much faster than that.
For that we need more details.
Can you describe the colour change on your plate during sensitizing.
As for your question about iodine depletion, 125 grams of iodine is more than enough and should last your for years if your iodine box has a good seal. Has your silica gel turned very dark red almost black? If so, that is a very strong concentration and should coat your plate, if polished well in less than a minute. What colour is your bromine in silica gel? Coat to a first iodine colour somewhere between yellow and magenta, bromine to full magenta (test with four quadrants of differing time) back over iodine for whatever you want. 1/2, 1/3, 1/4, 2/3. They all will work but you’ll figure that out with practice which is best for working environment.

My hunch with the information you’ve given is to cut everything by 2/3rds. Iodine, Bromine and Exposure,
Mercury is rarely the culprit for poor images, there’s a lot of latitude there. How big is your pot and how long did you develop for?

best

Mike

[Bingtan]

Hi John / Mike,

Thank you for the very fast response. Other details:

1) Weather temp – 35C
2) Mercury temp – 80C / 2 mins.
3) Iodine silica gel – very dark to black
4) Bromine silica gel – very orange. I know from another thread that Mike suggested it be light yellow but I didn’t have any other container right now to manage the bromine. That said, I’m assuming this is stronger so should give me a working idea.
5) Light meter reading was sunny afternoon sun – ISO 3 / f/2.8 / 1/250
6) My pot is good to fit a whole plate so it’s pretty big for a 6×6 but it really doesn’t seem like mercury is the problem…

Mike, the image is indeed that, very pale. The reason I assumed my coating was the problem because I made another exposure at 8 mins – both this and the 2nd image came out exactly the same.

Iodine at 3 mins was quite deep red. Bromine was pushing to about purple. Admittedly I wasn’t checking the Iodine color on the plate inside my “darkroom tent” for worry of fogging. I had based my 3 mins. while I was outside the tent making a test plate.

I will give this a try cutting fuming to the following:

Iodine – 60 secs.
Bromine – 20 secs.
2nd Iodine – 15 secs.
Exposure (given the same light quality) – from 30 secs to 4 secs.( 3 stops less ).

I guess my situation being in the tropics is very different from a lot of people’s experiences so I just wanted an initial point of reference. I will try fuming and exposing tomorrow and I’m keeping my fingers and toes crossed!

Thank you!!!

[photolytic]

Are your fuming boxes kept at 35C also.
If they are the concentration of Iodine fumes at 35C is 3 times as high as it is at 20C.
Therefore your fuming times should be only one third as long.
The deep red color you see may not be in the first cycle of colors.
I suggest that you try examining the plate during the fuming to determine what cycle of colors you are using?
Generally the speed of the plate is lower if you fume past the first cycle of colors.

[nawagi]

Bing-

The best advice I received from Mike, John, and others was to learn the colors of fuming. Chemical concentrations and ambient temperatures change. But the color spectrum of fumed silver is a constant, thought the progression of colors speeds up with heat and, thus, more chemical vapors.

I suggest you run several ‘sacrificial’ plates and watch the color progression develop through three spectral cycles. It will give you “eye memory” for the fuming color progression, and help when discussing fuming with truly skilled operators like Mike and John.

NWG

[Bingtan]

long day again…I was able to make a few plates but must say I’m still far off…here’s some details:

1) Weather temp – 35C
2) Mercury temp – 80C / 2 mins.
3) Iodine silica gel – 60 secs.
4) Bromine silica gel – 20 secs.
5) 2nd Iodine – 15 secs.

I tried doing some color inspection on a second plate but I when I started noticing the pink on 1st I, it took too long – 2 mins. Br was 30 secs. I went through the whole process again and the image was lighter – I think now I know the limit of when I went too far.

So I tested a plate outside of my tent and it seems like I get my first light pink at 40 secs. I will have to give this a go again tomorrow. The speed of fuming I assume would be highly related to my working temp – it’s just far warmer where I’m at. So my next experiment would be to go for:

1) I – 40 secs.
2) Br – 15 secs.
3) I – 20 secs.

I have a few questions regarding today’s plate:

1) When you’re looking straight at the image, it’s all bluish…I wonder if it’s under development? ( 80C at 2mins)
2) I’m just curious- I’ve never seen a real dag plate up close and I’m looking at everyone’s pictures and I see blacks. Is there really suppose to be any black? My images are primarily a thin layer of powdery white. I mean, if I’m shooting for black, it looks like I’m a long ways out! I tried purchasing one on ebay before but a seller sent me a tintype instead of a dag.
3) anyone got a properly expose plate they’re willing to let go off that I can buy? So at least I’ll have something to work my way towards.

Thank you for your advice. I must say, this is driving me nuts and today, I am starting to question the sanity of all this. It’s not easy…but I’m too far in to give up at this point!

Sincerely,

Bing

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[Andy Stockton]

Here is one small procedure that may help you. When I was first fuming plates I had a very hard time discerning the color changes during the fuming as they were very faint to my eye. Follow the suggestion from nawagi of using some sacrificial plates to focus on fuming color changes only (you can buff them again anyway). Then use the process below:

1) Tape a piece of white paper to the wall next to the surface holding your fuming box.
2) Lay an unfumed plate flat on that surface next to the paper (forms a 90 degree angle to each other)
3) Fume your sacrificial plate for five seconds
4) Take your fumed plate and lay it next to the unfumed plate
5) Shine a white light on both plates so they throw a reflection on the piece of paper (small flashlight)
6) The side-by-side reflection of fumed and unfumed plates makes it very easy to see even the faintest color difference.
7) Fume again for five seconds and compare the color difference
8) Keep repeating till you see all three color cycles
This process assumes you are working in a darkened room.

Some people seem to see the faint color differences very easily. I didn’t. I realized after trying this process that I had completely missed the first color cycle and was going into the second and even the third unaware. It can be hard to discern changes when you have never seen them before and have nothing to compare to. If my verbal description is unclear let me know. Hopefully you will find it helpful.

Andy

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