3 cycles Bdag gallery
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July 30, 2009 at 6:49 pm #7517bailunParticipant
Ladies and gentlemen!
My offer to create gallery 3 cycles Bdag.
For those who TODAY really works about 3 cycle.
Who counts 3 cycle the main and favourite place.
Please your pictures and parameters of shooting.
Who these people?
My forecast – practically anybody! We shall look?
It is necessary to create similar galleries for other cycles. Since 1 and indefinitely. There can be someone works THERE.
Here we shall see where operators Bdag sit and that they do(make) in what cycles.
Than cycles differ. What their advantage. What lacks.
BAILUN /Director of gallery 3 cycles Bdag.
Forward, comrades pilots! A white infinite chasm before you.
July 30, 2009 at 7:03 pm #9211Jon LewisMemberFor your consideration:
plate: 2 1/4″ x 2 1/4″ pure fine silver
iodine: 3rd yellow with a red tinge
lighting: inside, EV 10
aperture: 2.8
exposure: 30 minutes
development: 3 hours
gilded: no
Attachments:
You must be logged in to view attached files.July 30, 2009 at 7:10 pm #9213Jon LewisMemberplate: 2 1/4″ x 2 1/4″ pure fine silver
iodine: 3rd yellow with a red tinge
lighting: inside, EV 13
aperture: 2.8 (+3 stops for extension tube)
exposure: 30 minutes
development: 3 hours
gilded: no
Attachments:
You must be logged in to view attached files.July 30, 2009 at 9:24 pm #9217PobboravskyParticipantHi Jon et al Becquerellers
I would find it even more useful if the the (exposure)lighting type could be included in the description.
By lighting type I mean daylight, north light, tungsten, photoflood, fluorescent, and so on.
The effective speed of the plate depends on the blue content of the light.
Imagine a subject illuminated by north light which has lots of blue light. Now, imagine the same subject illuminated by a 100-watt tungsten light which has far less blue light. Imagine also that the meter gives identical EV readings for these two light sources. Since the EV is identical it might seem reasonable to give identical exposures. However, if the north light image is correctly exposed, the image with the tungsten light will be grossly underexposed.
Why is this so? Light meters respond to the entire visible spectrum; an iodized plate responds only to the blue light getting through the lens. UV radiation is absorbed by the lens.
I wonder if the exposure discrepancy in 3rd cycle yellow plates between Monsieur Bailun and Monsieur Meegan might be due the difference in the blue-light quality used by M.Bailun.
Monsieur Irv
July 30, 2009 at 11:24 pm #9221bailunParticipantPatriarches sometimes descend(go) from heavens on the ground!
In last phrase soft and delicate attempt to justify and rescue old guards. The academic aristocratism. It to you not cowboy Marlboro. a little French. pas mal, pas mal …
And why to you to not earn 100 $. And to make Bdag Monsieur Meegan? Why is not present? There on clouds?
These are questions to Meegan. why it(he) did not speak WHAT light! By default this sun. Now covered with a transparent cloud 14 EV.
Now here it is possible, but it is not necessary to add geographical breadth of shooting. For example southern borders Russia are northern borders usa. theoretically our light worse for dag. still Monsieur Arago spoke that in Egypt to shoot better, than at Paris.
Now here it is possible, but it is not necessary to add height above sea level. Than above UV radiation more – it is better.
/Jerry in Peru /
Affinity and shooting on poles / Joyce Campbell in Antarctica/ remember fashionable ozone gaps. Now forgotten. Now Obama it is fashionable! And inauguration Obama !
Add to this seasons of year! Spring winter summer autumn
Time of day / height and a corner above the ground
/This why an image taken between the hours of 10 00-16 00 is more vivid, than shots taken during other times of the day even though the light intensity is elevated./ Carlos Darío Albornoz Argentina
Question of LIGHT FOR DAG – KEY.
Quantity(Amount) of light LUX – a priority. In my opinion. The second – quality. Proportional presence UV radiation in lamps in percentage to solar – is very good! What is average interest?
Just now, read your work. Recently has transferred(translated). Thank. Good work. It approaches us to evident understanding of physics of process.
So as far as approaches / in volume of the given work – thickness important to know/
Last paragraph has touched.
/the Becquerel phenomenon: this maximum speed is roughly equivalent to an exposure index of 0.0008 or 60 seconds at f/4.5 on a bright, sunny day./
At you exponometr then was not? / bright, sunny day. / when, where, how many? Look above.
I shall repeat
EV 14 = 40000 lux
EV 15 = 80000 lux
EV 14 twice there is less than light!!!
And all this bright, sunny day at the end of July in RUSSIA 2009.
And that will be bright, sunny day in the winter 2010 on Alaska I do not know.
July 31, 2009 at 7:28 am #9231bailunParticipantIf will allow, the professor a question at you.
I the bad mathematician.
expo 0.002 SEK / ISO 100 / EV 14 / F 2.8/
pls how many will be by your theoretical calculations expo for the fastest 1 cycle? Then we shall increase it on 3 thickness of a layer and we shall receive theoretical figure. Which will confirm theoretically or will deny proofless applications Meegan.
I hope your calculations will inspire the shameful duellist.
Or your calculations with index 0,0008 I do not work practically? Then that it for the theory?
Also audit of an estate of the French aristocrats is necessary?
Thank you
July 31, 2009 at 7:29 am #9233bailunParticipantSorry. But, DagForum starts not correctly works. Has not time.
July 31, 2009 at 6:11 pm #9235PobboravskyParticipantM. Bailun,
The last Becq. d-type I made was probably in 1970. I have enough trouble making mercury-developed d-types. I am not interested in making Becq d-types. 3rd cycle yellow plates tend to fog. Jon’s 3rd cycle images are not fogged. This means he knows how to make such images which is more than I know.
Since I have never made a successful image on such a plate I have no idea if Gerald Meegan’s short exposure time is correct. I know he is a veryclever man who has made some very interesting observations.
I do not know how to predict the speed of a 3rd cycle plate based on the speed of a first cycle plate.
M. Irv
July 31, 2009 at 7:12 pm #9236bailunParticipantThank for the answer.
All of us here very clever people also do(make) very interesting supervision. Each experience is invaluable.
Only we yet did not see Meegan’s 3rd cycle yellow 7 seconds.
I regret that you have stopped interesting scientific experience with physics and chemistry of process. Now only practice.
pls I shall repeat
expo 0.002 SEK / ISO 100 / EV 14 / F 2.8/
how many will be by your theoretical calculations expo for the fastest 1 cycle with index 0,0008?
Thank
July 31, 2009 at 9:27 pm #9238PobboravskyParticipantM. Bailun,
With the incident meter set at ISO 100, EV=14, f/2.8, outdoors — a first cycle exposure time would be about 20 seconds. Based on your experience, does this seem to agree with your results? Other workers: please let us know if this seems about right?
In my 1970 work I found that a first-cycle yellow is more sensitive than a second-cycle yellow. However, the image made with a 2nd-cycle yellow is much less contrasty than that of a 1st-cycle yellow. A 1st cycle yellow plate because of its very high contrast must be used with flat lighting – like on an overcast day. On a bright sunny day the shadows will come out dark and without detail – assuming the plate is exposed to get correct highlights.
A 2nd-cycle yellow plate does a better job of recording information in the highlights and the shadows. You need not be limited to shooting on an overcast day. But it is not as fast as a first-cycle plate.
What Meegan found is that the effective speed of a 2nd cycle plate can be increased by increasing the Becq. development time to hours instead of the 20 minutes used in my 1970 experiments. Increasing Becq. development time to hours also had the benefit of producing neutral tones instead of the bluish tones obtained with shorter dev’g times. He also experimented with dev’g times of 24 to 48 hours and with cycles greater than 2. I have seen some of his images and they look similar to ones dev’d with mercury.
By increasing the total light energy used in extended development — it compensates for “underexposing” the plate in the camera.
Does any of this make sense?
Irv
Gerry Meegan found that he could
August 1, 2009 at 6:04 am #9240bailunParticipantThe professor, please it is not necessary so delicately, softly, it is thin, but persistently to justify GM.
I would not think that you began so persistently to justify GM if tried to realize in practice his(its) recommendations. Your enthusiasm with the justification will quickly end in real work with a real material damage. It is delicacy of the detached onlooker after a good tasty dinner with a cigar and a glass dearly cognac. You do not smoke I hope?
Here professional conversation to the point.
– 20 seconds?!
The professor, apparently, just you has killed Gerry Meegan. Delicately!
– 20 seconds it is possible to agree. It is similar to the truth. I think, will be little bit less.
It will be natural 3 cycle more.
The sensation for all will see your 70 Becqs! PLS!
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