menashe_soffer

<p>paul<br>

using the weekend to contunue ith troubleshoot.</p>

<p>I have extra focusing screen, I have disassembled to use the glass as a reference on the film plan - it fits into the film rails.<br>

what I have found, and i didnt know before, is that the glass have "front" and "back" sides; meaning i see the imaged focussed in the film plan in one case and not in focus if I attach the other surface of the screen to the rails. in the same way I get different view if I re-assmble the focising screen into its holder in two different ways.<br>

how do i know which surface of the screen should face the mirror (or lens) and each the magnifier (or luope)? it occured to me that the only problem may be that the screen I got was assembled up-side-down, and the "calibration" I make will actualy adapt to the wrong assembly of the screen.</p>

<p>paul</p>

<p>started iterating in some sort of "trial and error" (tuning - checking with film) following your guidance; need few more itterations but seems in the right direction.</p>

<p>thanks for your quick and relevant advice!</p>

“split image” is num. 3 “rangefinder”; it seems that the screen is placed correctly

Paul, “re-focus the screen” – how is it done?

when I take the screen out, I see in the corners of the base 4 screws (heads with spanner drills); it seems that theoretically I can adjust the screen height if I turn them. am I supposed to tamper with these screws?

in addition, suppose I can find ground glass, who do I manage to position it on the film plane?

<p>hello<br>

bought a RB67 from one of the leading used camera dealers; have big troubles focising the camera.<br />I made the following experiment:<br />placed 6 targets ~2cm apart, and the camera ~1m from the targets;<br />I tried to focus on the 3rd (the one marked with arrows), I am pretty convinced that the split image converged to this one ( I made everything very slowly with tripod).<br />however the real focus seems to be somewhere between the 4th and 5th target, ~2.5% deviation.<br />my questions:<br />* since the camear is focused beyond what it seems in the focusing screen, it means that the lens-to-film distant is shorter than the lens-to-focusing-screen distant, right?<br />* is it possible that the camera is OK and i am doing something wrong, for example looking at the finder from wrong distance/angle? (never had problem in 35mm)<br />* any suggestions how I can use the camera or I should return it?<br />thanks</p><div></div>

<p>stuart</p>

<p>your result is surprising; I did not get anything near by just "unsharp mask"<br>

can you describe the sequence?</p>

<p>hello</p>

<p>I have read very good reviews on viewscan so I wanted to give it a try;<br />naturaly wanted to test the demo first.<br />I my test the results were unacceptable; they were so bad that I am convinced that I used wrong settings.<br />Attached is the example comparing an old scan I did with the Epson scanning software (smartPanel) and the same scanned with viewscan. in both i didnt tweeked with scanning parameters and did very little PS (sharpening). the viewscan is unacceptionaly soft.</p>

<p>I did not changed the default viewscan settings other than setting "B&W negative", "16-bit gray" and "3200DPI" in the input tab. anyone can think about something?</p>

<p>Thanks</p>

<p> </p><div></div>

<p>hello</p>

<p>I have epson 3200 PHOTO; i have used it for few years with win-XP.<br>

I have mooved to WIN-7 now and the installation disk is incompatible with the OS.<br>

I have downloaded new TWAIN driver from epson support but the new driver only supports basic scanning - no

film scanning.</p>

<p>anyone knows what software I can install to use EPSON 3200 wive WIN-7?</p>

<p>thanks</p>

<p>look at the milky tone in the shaded part of the boat.<br>

this is an example; I keep getting similar results with my ARAX-60. I have two lenses and I get this fault with both. luckily I dont encounter this problem with other camera.<br>

any idea hat will help to spot the problem is welcomed.</p><div></div>

this only happens if the negative curl.

for some of the worst negative I scanned, I cut 2 pieces of carton and placed them below the negative, above and below the frame.

not very convenient and you can't scan a complete row in one shot but it flattens the negative to an extent that prevents the rings.

what about just washing the film?

when I process a "modern" film like TMAX and to some extent Fuji neopan, I always get DEEP pink-reddish tint after fixing.

as an amateur I don't care about efficiency (processing time), so I wash the film for very long time, 30~40 min. The tint completely removed by the long wash. the base fog remains, though...

thanks for the enlighting responces.

I'll try to figure our a consistent workflow but I now realize I was in the wrong direction.

Hello,

once again trying to make sense out of the material

to start with, my current understanding is that if everything is calibrated, the visible luminance to be displayed is

equal to the stored value to the power of gamma; as an example a stored value of 0.46 will be translate to 0.46^2.2 =

0.18 Imax.

If I try to translate this to traditional "zones" in which every "zone" is twice as bright as the previous zone, and

arbitrarily call 0.18Imax "zone 5", than I get the relation:

I/Imax = k^gamma (k is stored luminanace value)

zone = log2(I/Imax) + 7.47 (the constant is arbitrary to put 0.18 as "zone 5")

--> zone = gamma * log2(k) + 7.47

--> k = 2 ^ [(zone - 7.47) / gamma]

I'm asking all these questions because I am trying to find a procedure to calibrate my scanner.

I was thinking of making test frames with different exposures, "zone 5" is metter reading "4" is one stop

underexposed etc., than develop and create a 'curve' that will map according to the last equation, e.g. mappinf

according to:

relative expore k (file value)

+2 (zone 7) : 0.86

0 (zone 5) : 0.46

-2 (zone 3) : 0.24

is this reasonable procedure?

I am asking because I mostly scan B&W, I dont understand the IT8.7 calibration process and I didnt notice any

negative film IT8.7 target.

nevertheless if anyone know what are the densities in the IT8.7 lower strip (GS1-GS22) it will be nice to get the data.

this information will make it possible to use the scanner as a densitometer.

thanks

thanks

recently I have spent an effort attempting to get consistent and standard results, e.g. started to use 'spider' for

monitor calibration, to profile the scanner etc.

it seems to me however that even with all these advanced equipment and procedure, the simplest question is still

unanswered (for me): how should I set the monitor brightness and contrast?

monitor contrast seems to be the most dominant factor in determining the actual look of the image, yet I did not

encounter yet any instructions how to compensate for differences in contrast among devices. Of course that after

modifying the contrast setting I re-calibrate the monitor, still the images look completely different. Most tutorials

advise 'setting the monitor to the highest contrast' but I doubt this is true for several reasons:

* there is lots of variance in top contrast among monitors; new LCD's has huge contrast how can I predict how an

image will look like in a different monitor if contrast is not standardized?

* tried to print some files in photo labs, I always get much darker and less contrast prints, although the was

advised that the printers are calibrated to sRGB.

in addition I find working with monitor at highest contrast very uncomfortable....

so here is the question again: what is the real standard for contrast setting?

thanks for the answers;

Jordan, you captured exactly what I am trying to do.

No, I did not try Dektol, I thought it is supposed to be very similar to D-19. I read that D-72 is very similar to Dektol. if I normalize the relative amounts of ingredients, I see that the development agents (MQ) and the accelerator have exactly same relative concentration in D-19 and D-72, but the preservative and restrainer are 3 times more concentrated in D-19. I don't know what that means.

Patrick, I think the gamma product is still applicable to the LINEAR portion of the overall process. My suspicion, when said "condensed blacks", was that for some reason I am NOT getting LINEAR response. but maybe I am interpreting all that wrong. Is it possible that significant portion of the positive is coming from the non-linear part of the curve? If this is the case, how longer exposure fixes it - with shorter development I get lower gamma, will it help to raise the achievable Dmax?

Hello

I am experimenting with negative to positive (slides from negatives).

Using TMAX-100 to create the positives and home-made D-19.

The problem is that the darker araes sems to be condensed.

I did not make accurate experiments but I can say that according to impression I get from real images. I can

quantitavely explain my expression in zone terms.

agree that "Zone 10" is black on original negative / white on positive.

Than my impression is that zone 5 becomes 3 (darker than it should be) so there is too much definition in the

ligher zones a.k.a zones 6-10 streching to occupy 4-10 on the expanse of the darks zones 1-5 contracted to 1-3.

Which variables I can use to controll the "shape" of the curve and how (change ingrediants fraction in the D-19

formula, push/pull, agitation, dilution).

thanks

hello

trying to start with color management from zero

i have re-installed the monitor driver.

i am using windows XP.

now under control panel --> display --> settings --> advanced --> color management, in the "color profiles

associated with this device", i see the monitor (LG1760TR) name.

please advise what is the best course of action:

(1) should i leave this profile as is

(2) leave this profile associated to the display but update it (using adobe gamma etc.)

(3) select to associate something different e.g. adobesRGB (and calibrate)

(4) something else

thanks

I will appreciate recommendations for text book or web resources on preparation

of material for print.

I scan my negatives and occasionally get on he monitor results that I am pleased

with, however when taking the files to print in a lab the results ranging from

disappointing to disastrous.

I assume part of it involves "color management" (calibrating the monitor and

working with profiles) but I guess it isn't the complete story. for example if I get very

good details in black area on the monitor and no details at all on the print, it must

have to do with something beyond gamma curves.

in addition to this general question I would also like to ask if the various consumer

grade monitor calibration devices are useful for the purpose of B&W "color

management". I'm asking because my intuition is that there are different things to

stress for B&W: the absolute luminance and accuracy of gamma are important,

while for color it is possible to "round the corners" only the matching among the 3

color channels really matters.

Durest M600 seems like a very tempting deal. The problem is that parts are very rare and you risk ending up either not using the enlarger or spending lots of effort time and money to find the parts you need.

A concrete example from my experianc is the lens board. You are most likely to get the enlarger with the normal lens board that has 25mm thread; that is OK if you also gt the 75mm lens that usualy comes with it and you are satisfied with that. if you want to change lens, for example if you want to work with a 50mm lens to get decent magnification of 35mm film, you will need to find an accesory lens board, good luck!

my advice is that unless you run a machining workshop go for another model.

what part of the scene should be measured, shadow or highlight?

I understand that exposures metters suppose to measure the shadows (lower density in negative --> more light available to metter)

however isn't exposure supposed to be dominated by highlights (denser areas of negative)?

I don't know the Besseler but I bought M600 few years ago;

theoretically it is very good - very rigid construction, a 'flexible' format up to 6x6.

practically you will almost surely need replacement parts because the lens board will not fit most enlarging lens and in addition different lens boards required for different focal lengths because below extension length is limited. It is almost impossible to find these replacements and if you find it will cost more than the enlarger.

I also had lots of 'Newton ring' problems with the negative carrier.

I don't remember every details I didn't use it for quite a time it gathers dust in the closet.