OP
OP
started a return with B&H. I cannot ever reccomend this product. and yes it also leaks.
Under exposed results
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How is that a problem? It's kind of obvious you'll have liquids trapped between adjacent sheets of plastic, one of which is flexible. They'll suck together. It's also not a problem in terms of processing; you can get the same with tray development where a sheet can stick to the bottom.
Have you verified the bands are actually present on the negatives and not just on the scans? Keep in mind that if you scan very thin (underexposed and/or underdeveloped) negatives, you'll end up amplifying any kind of anomalies (including arising from the scanner/scanning process itself) when boosting contrast to a normal range. Essentially you're dealing with a poor signal/noise ratio.
How is this scanned? Flatbed? Camera? What kind of setup?
I'd also like to repeat my request for an image of the actual negative(s). Just pop a negative onto a light box (or any light source with diffusion) and take a photograph, post it here. Scans are 'nice' but there's so much doctoring on them that it's impossible to tell much about the nature of the negative and associated problems.
Jumping to conclusions tends to result in waste of time and money. With large format, you'll find the penalty is severe. Take it slow, one step at a time, and be systematic.
Looking at this, I think you have a lighting/metering problem. From what I see from the catchlight, you only have one strobe, located on the left side of her face (right side of the frame), is that it? If so, normal that the right side of her face is underexposed.
With a single strobe, you cannot use this setup and expect anything else, especially if you meter from the strobe side. So, either you change the setup of the single strobe to include more of the right side, add a fill on the right side, or meter (incident) from the shadowed right side. Last solution will ask you to find a compromise between the two readings, if you don't want your highlights to be blown.
Portrait photography with a single light source is tough.
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This is in response to post #16 regarding computing exposure compensation.
The number of f-stops of additional exposure required to compensate for lens extension based on the distance E from the second nodal point of the lens to the image plane can be written in several equivalent ways, such as
Δf = (2/ln 2)*ln(E/f) = (1/ln 2)*ln(E/f)^2
Taking note that the factor 2/ln 2 has the constant value 2.885 rounded to 3 decimal places, we can more simply write this as
Δf = 2.885*ln(E/f)
We can test this with an example we all know. When we extend the lens to 2f from the image plane to obtain 1:1 magnification, the exposure compensation is 2 stops.
For your 250 mm lens positioned so that E = 500 mm,
Δf = 2.885*ln(500 mm/250 mm) = 2 stops
You can also see that this gives the correct result at infinity where E = f. For a 250 mm lens,
Δf = 2.885*ln(250 mm/250 mm) = 0, as expected.
You can also compute exposure compensation based on subject distance and focal length.
Exposure Compensation in Terms of Subject Distance
Time factor = [s/(s – f)]^2 where s = lens-to-subject distance (subject to 1st nodal point)
Compensation in f-stops = Δf = 2*ln[s/(s – f)]/ln2 = 2.885*ln[s/(s – f)] (since 2/ln2 ~ 2.885)
Magnification = f/(s – f) for s > f. When s = f (infinity focus), then m = 0.
The proper logarithmic function to calculate exposure compensation due to an extended lens is the natural logarithm which uses the base e, where e is Euler’s number e = 2.71828182846 . . .
Scientific calculators have both common (base 10) and natural logarithms built in. Typically, calculators don’t have base-2 logarithms built in.
The number of f-stops of additional exposure required to compensate for lens extension based on the distance E from the second nodal point of the lens to the image plane can be written in several equivalent ways, such as
Δf = (2/ln 2)*ln(E/f) = (1/ln 2)*ln(E/f)^2
Taking note that the factor 2/ln 2 has the constant value 2.885 rounded to 3 decimal places, we can more simply write this as
Δf = 2.885*ln(E/f)
We can test this with an example we all know. When we extend the lens to 2f from the image plane to obtain 1:1 magnification, the exposure compensation is 2 stops.
For your 250 mm lens positioned so that E = 500 mm,
Δf = 2.885*ln(500 mm/250 mm) = 2 stops
You can also see that this gives the correct result at infinity where E = f. For a 250 mm lens,
Δf = 2.885*ln(250 mm/250 mm) = 0, as expected.
You can also compute exposure compensation based on subject distance and focal length.
Exposure Compensation in Terms of Subject Distance
Time factor = [s/(s – f)]^2 where s = lens-to-subject distance (subject to 1st nodal point)
Compensation in f-stops = Δf = 2*ln[s/(s – f)]/ln2 = 2.885*ln[s/(s – f)] (since 2/ln2 ~ 2.885)
Magnification = f/(s – f) for s > f. When s = f (infinity focus), then m = 0.
The proper logarithmic function to calculate exposure compensation due to an extended lens is the natural logarithm which uses the base e, where e is Euler’s number e = 2.71828182846 . . .
Scientific calculators have both common (base 10) and natural logarithms built in. Typically, calculators don’t have base-2 logarithms built in.
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OP
OP
Thanks for the math explanation, it is great !
I will post up a negative or two this evening.
thanks for all the support!
as for the strobe setup, yes understood, was not a particular attempt at anything special.
Just got the camera and lens, had to try it out
I will post up a negative or two this evening.
thanks for all the support!
as for the strobe setup, yes understood, was not a particular attempt at anything special.
Just got the camera and lens, had to try it out
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If it's your first try at working large format, normal that mistakes are made. Learning curve going from 35mm or 120 to LF is steeper than expected. And even if you have some experience in LF, this is still the best advice you'll ever get:
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OP
OP
Hi, thanks, no It has just been a while, have worked with 4x5 and... 8x10 before, Jobo, hangers in a tank and tray
Also I want to apologize to all for getting steamed up over the performance of the holders. I do know it is an issue with Ilford film. However i do want to use Ilford, right so.. The holders are so very easy to load compared to the jobos I had in the past.
I will make it work eventually.
Also I want to apologize to all for getting steamed up over the performance of the holders. I do know it is an issue with Ilford film. However i do want to use Ilford, right so.. The holders are so very easy to load compared to the jobos I had in the past.
I will make it work eventually.
OP
OP
In fact this is probably one of the dumbest useless threads i have ever started, as all the so called problems here were between my ears.
But at least I got a math lesson
But at least I got a math lesson
Not really; It's not a dumb thread at all.
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MattKing
Moderator
In fact this is probably one of the dumbest useless threads i have ever started, as all the so called problems here were between my ears.
But at least I got a math lesson
Sometimes Photrio can be like a good counsellor - by helping you verbalize your problems, we help you deal with them.
Sometimes Photrio can be like a good counsellor - by helping you verbalize your problems, we help you deal with them.
OP
OP
Ok lets see if I can behave like some sort of an Adult tonight!
these are the D700 scans of one Negative. Cropped and resized to fit here.
nothing else. (upon examination I missed the focus though lol)
Ilford FP4+ (one of the problematic films it seems)
The first presentation is the Negative, with only distilled water used as a wash, followed by distilled water with photo flo.
The Second presentation is the same Negative, after 12 minutes of continuous washing in a large measuring cup, cold side, running tap water in the sink, with turbulence almost enough to float the Negative out of the cup. Then followed by 5 minutes of soaking/gentle agitation in a tray with distilled water and Photo Flo.
2.
OP
OP
Now, I have no intention to bash the product like I did before, that was pretty much uncalled for.
I know that had to bust but for many hours to get this going, to the benefit of a fairly small group of people.
In fact I hope they can come up a newer design to fix it once and for all.
The Economy of developer and the easy loading are quite important.
I wonder....about drilling holes on the bars...
Due to the cost of Ilford versus say Fomapan, keeping and using this tank with Fomapan will save money in the long run.
The results I have had with 35mm Fomapan 100 and D23 have made me quite happy.
I know that had to bust but for many hours to get this going, to the benefit of a fairly small group of people.
In fact I hope they can come up a newer design to fix it once and for all.
The Economy of developer and the easy loading are quite important.
I wonder....about drilling holes on the bars...
Due to the cost of Ilford versus say Fomapan, keeping and using this tank with Fomapan will save money in the long run.
The results I have had with 35mm Fomapan 100 and D23 have made me quite happy.
Consider focusing on the test started first which tells you the bellows extension factor right with it. I can send you a free PDF if you mail me that.rwlambrec@gmail.com.
OP
OP
Email sent, thank you!
Forgive me for asking again, but are you certain that you have the emulsion facing away from the holder? I ask because I use the same holder and processing tank and same film without getting density bars like that. Only significant difference between us is that I process the FP-4 in DD-X and wash with the Ilford wash routine, although I generally wash about 50% more. I agitate per Ilford spec but rock the tank side-to-side because I can’t get mine to not leak. This is perplexing.
OP
OP
Yes definitely emulsion side out. One of inherent features of the stearman holders is handling the film exactly as I remove it from the cameras holder
Notches upper right when loading both
Notches upper right when loading both
OP
OP
TF4 fixer, typically 3.5minutes. Agitation per instructions
Well, gosh… I’m out of ideas. I’m sure you will work it out and I know how frustrating this must be for you. A really mystery! Have you considered showing Tim at Stearman Press your dilemma?
OP
OP
I’ll take a pic and develop another negative. Fresh fixer.
OP
OP
the more I think about it.... I bet I DID flip the film and put emulsion against the frame. Nothing brain surgery with a fork cant fix.
Don't bother with bain surgery. The longer we live the more that normal age-related memory loss and dementia do the same thing.
OP
OP
Thank you all for attending my CLOWN SHOW. I hope you all got great pics!
Here is why it everything sooooooo eassssyyy for me....
I am left handed.
reasonably dyslexic.
impatient much to often
And a cup full of Dunning Kruger effect DNA.
Yes, I took the film out of the 4x5 Holders exactly as I put them in and transferred to the Tank Holders...
I think you can now read between the lines... or perhaps peek under the darkslide....
thanks for your patience with me.
this has been quite embarrassing LOL.
Here is why it everything sooooooo eassssyyy for me....
I am left handed.
reasonably dyslexic.
impatient much to often
And a cup full of Dunning Kruger effect DNA.
Yes, I took the film out of the 4x5 Holders exactly as I put them in and transferred to the Tank Holders...
I think you can now read between the lines... or perhaps peek under the darkslide....
thanks for your patience with me.
this has been quite embarrassing LOL.
OP
OP
Even sadder.. all I had to do was pick up a negative and look at the orient of the subject….
This is like golf. Lol
This is like golf. Lol
MattKing
Moderator
Us "sinister" people like to stick together.
You have no reason to be embarrassed.
You have no reason to be embarrassed.
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