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Drew Bedo
8-Feb-2021, 06:45
I bought a box of 4x5 dry plates by Lane. I rated and exposed them per the label at ISO 2. Sent them off to Blue Moon for processing. They are significantly under exposed, some showing no discernable image while most have an image only suitable for scanning as a negative with enhancement in photoshop.

I am ok with this as this is my first use of glass plates of any sort and my first use of materials from Lane. This post is not intended to be a complaint.

My question is: What is a reasonable ISO rating for these materials if the intended use is to create Ambrotype style images to be viewed by reflected light? I am now guessing something like 1.0 or 0.5.

Tin Can
8-Feb-2021, 07:28
The color of your light matters

Alan9940
8-Feb-2021, 07:33
There is a chart somewhere on Jason's website that shows estimated ISO for various months of the year, etc. Out here in the desert southwest, I lean toward ASA 2 during summer months and in the middle-o-day timeframes, and around ASA 0.5 this time of year. I believe the temperature of the light--early morning, late afternoon into early evening--affects the ISO rating, too. It's pretty much guess work, really. All that said, I lean my guesses toward more rather than less exposure.

Tin Can
8-Feb-2021, 07:39
https://www.pictoriographica.com/technicals-and-tips.html

jim_jm
8-Feb-2021, 10:59
I also had some issues with underexposure on my first batch of plates, just a matter of getting used to the different sensitivity from film.
I asked Jason about reciprocity factor for long exposures, and this was his advice:
"My rule of thumb is to add about 50% time above 45 seconds, and then double above 2 minutes".

So far this has worked well and I'm learning to adjust to the different sensitivity of the plates.

Drew Bedo
8-Feb-2021, 16:17
Thanks for that everyone. I will adjust.

m00dawg
8-Mar-2021, 13:44
I've only shot a few of these but for what it's worth, rating at an ISO of 2, my first test plate was exposed using a 18% gray patch on my color char. That one came out with some dense highlights but still usable and quite nice. The second I metered, also at ISO 2, in the shadows of a building. The meter read 1/30 but I used 1/20 (as that was the closest, rounding down, shutter speed on my Velostigmat 6"). This resulted in a thinner but still very usable negative.

My third test is to use a blue filter in front of the meter and see what that gives me. I'm just worried the filter might require a filter-factor correction so not sure if I should use that over the lens as well.

Final test is to play maybe play with some strobes.

Not sure if that is helpful or not but thought I'd share just the same!

Of note, I developed the plates myself using HC-110 B per J Lane's recommendations. Tried and true but I would like to experiment with some other developers, notably Adox XT-3, Eco-Pro, Mytol (basically the Vitamin-C Xtol-like developers).

Nodda Duma
8-Mar-2021, 14:35
If you experiment with different developers, you can develop by inspection under safelight. Donít pull the plate until it looks *too* dark under safelight.

Iíve had some luck with a blue 47 filter in front of the meter and using the exposure I get when setting the meter to ISO 8 (itís not really ISO 8 of course, but compensates for filter factor).

m00dawg
8-Mar-2021, 17:07
If you experiment with different developers, you can develop by inspection under safelight. Don’t pull the plate until it looks *too* dark under safelight.

I’ve had some luck with a blue 47 filter in front of the meter and using the exposure I get when setting the meter to ISO 8 (it’s not really ISO 8 of course, but compensates for filter factor).

Yeah sage advice as I pulled the last sheet a bit too early I think. Although at least the scan looks just gorgeous and I think it should be printable in the darkroom. Also just to be sure, the ISO 8 is for the ISO 25 plates I assume? If I did my math right, that'd be 1.5 stops?

Nodda Duma
8-Mar-2021, 17:24
No that’s for the ASA 2 plates.

Blue 47 filter blocks (approximately) the wavelengths the emulsion doesn’t see, but also chops down the throughput in the wavelengths the emulsion does see, so you adjust your meter two stops up to compensate (remember, ISO setting on the meter is just an electronic gain adjust for the read circuit).

When metering thru a blue 47 filter with J Lane Speed Plates, you’d set ISO rating to 100 and use the reported exposure.

Another way to think of it is...If you don’t compensate +2 stops, then metering through a blue 47 filter will result in +2 stop overexposure.

m00dawg
8-Mar-2021, 19:45
No that’s for the ASA 2 plates.

Blue 47 filter blocks (approximately) the wavelengths the emulsion doesn’t see, but also chops down the throughput in the wavelengths the emulsion does see, so you adjust your meter two stops up to compensate (remember, ISO setting on the meter is just an electronic gain adjust for the read circuit).

When metering thru a blue 47 filter with J Lane Speed Plates, you’d set ISO rating to 100 and use the reported exposure.

Another way to think of it is...If you don’t compensate +2 stops, then metering through a blue 47 filter will result in +2 stop overexposure.

I think I got that. I had to sit and re-read that a few times :) Alas I don't have a real Blue 47. Just a set of colored generic filters I was going to use for some trichrome stuff . I bought those in part because finding blue filters has been rather difficult/expensive though I do now see there are some available from various places. So yep I might have to pick up a proper one - seems like that would make metering just a little easier.

Drew Bedo
9-Mar-2021, 06:16
Jane Speed Plats?

Kiwi7475
9-Mar-2021, 08:42
My experience with shooting in a studio environment with incandescent light and modifiers is that both ISO 25 and ISO 2 plates need 2.5 stops more light (is. the ďtrueĒ iso is lower by 2.5 stops) than what the metering tells me it should, plus then reciprocity/bellows corrections on top of that of course.

Note I develop in Diafine 3+3 minutes, 1 min stop wash with water, Ilford Rapid fixer for 4mim, wash for 10 min, photoflo for 30sec.

Nodda Duma
9-Mar-2021, 10:13
My experience with shooting in a studio environment with incandescent light and modifiers is that both ISO 25 and ISO 2 plates need 2.5 stops more light (is. the “true” iso is lower by 2.5 stops) than what the metering tells me it should, plus then reciprocity/bellows corrections on top of that of course.

Note I develop in Diafine 3+3 minutes, 1 min stop wash with water, Ilford Rapid fixer for 4mim, wash for 10 min, photoflo for 30sec.

Sounds about right. The drop in speed indoors didn’t start getting addressed until the mid 20th C and even modern films lose a stop indoors. Of course the dry plates don’t take advantage of those “modern” innovations. :)

Diafine! I have a can ready to mix to see how the plates respond to that unique developer.

paulbarden
9-Mar-2021, 10:20
I found that outdoors under heavy overcast conditions, especially during the winter months, the speed of the 2ASA plates is more like 0.5ASA. I've found this to be true when shooting in dense shade conditions as well.

Doug Howk
9-Mar-2021, 14:42
Testing the 25 ASA plates [5X7] in studio with still life. Using Ilford FP4 as comparison [15 secs at f45], the J lane plate exposed for 120 secs; and yielded a thinner but printable image. Lighting was two soft boxes with spiral florescent tubes.

Kiwi7475
9-Mar-2021, 19:06
Sounds about right. The drop in speed indoors didnít start getting addressed until the mid 20th C and even modern films lose a stop indoors. Of course the dry plates donít take advantage of those ďmodernĒ innovations. :)

Diafine! I have a can ready to mix to see how the plates respond to that unique developer.

I havenít done a lot of comparisons against other developers, but I find Diafine works very well with your plates.

Kiwi7475
9-Mar-2021, 19:20
Testing the 25 ASA plates [5X7] in studio with still life. Using Ilford FP4 as comparison [15 secs at f45], the J lane plate exposed for 120 secs; and yielded a thinner but printable image. Lighting was two soft boxes with spiral florescent tubes.

A couple of notes... reciprocity isnít the same in general so the numbers may not be directly comparable. It would be best to run some test comparisons in the <1 for FP4+ so that reciprocity is not a factor. I did comparisons running each 1/4 of a plate with increasing (doubling) exposure by pulling the slide in 1/4 increments. That saves plates :-)

Second thought is that the emulsion is most sensitive to UV. Every type of light will have a different % of effective power at the range of wavelengths that the plate is sensitive to. Different people may experience different speed depending on the light type. Just like with collodion.

Drew Bedo
10-Mar-2021, 05:24
So do or do not use a UV filter outdoors?

Would using a UV filter give a gain in sharpness along with a drop in effective ISO rating?

How do the J. Lane plates respond to strobes? I use older Vivitar 283s on still lifes indoors.

Is anyone creating Ambrotypes using J. Lane plates?

ernie57
17-Mar-2021, 17:35
I’m only into my first box of plates, so I expect to be fighting the learning curve. I shot some plates last week, outside, middle of the day near the ocean. Held a blue #47 filter over the meter with ISO (I still like ASA better) 100. These plates came out properly exposed. The 2nd outing, I was shooting cars, in the sun, middle of the day, and used the same metering technique, but everything came out very thin. Thin to the point of unusable. The thin ones are drying right now, or I would put up a scan. What is the difference in why I got such thin plates the 2nd outing? Thanks.

Jim Noel
17-Mar-2021, 18:14
I treat the plates the same way I do Ortho films. If the UV is low, I add exposure. If high, like a bright clear day between 10 AM and 2 PM I can usually use Box Speed.
I grew up with orthochromatic films prior to the domination of panchromatic films so this method comes naturally to me,

ernie57
17-Mar-2021, 20:35
Thanks. This makes sense and calls for further experimenting.

Nodda Duma
18-Mar-2021, 02:35
I’m only into my first box of plates, so I expect to be fighting the learning curve. I shot some plates last week, outside, middle of the day near the ocean. Held a blue #47 filter over the meter with ISO (I still like ASA better) 100. These plates came out properly exposed. The 2nd outing, I was shooting cars, in the sun, middle of the day, and used the same metering technique, but everything came out very thin. Thin to the point of unusable. The thin ones are drying right now, or I would put up a scan. What is the difference in why I got such thin plates the 2nd outing? Thanks.

If it’s from the same box then I’d check for problems elsewhere: Lens settings, developer exhaustion, etc. The plates are very consistent. Metering thru the filter would address UV variations.

Outdoors under the conditions you describe, you can ditch the blue filter and just spot meter on a gray card at ASA 25. That speed is calibrated to mid-March northerly lighting clear sky conditions at my latitude in NH.

ernie57
18-Mar-2021, 09:14
No doubt it was operator error. I’m not questioning the plates. I will be shooting more exotic vehicles on Sat. I will try metering with no filter @ ISO 25. Is the blue filter suggested for cloudy skies? What will happen to the amount of blue light in the SoCal area as we move into summer? I looked at the chart on your website and don’t fully understand what I am looking at. Thanks -

ernie57
23-Mar-2021, 23:59
I am still having a hard time getting exposures correct. I shot my first box and only got 1 useable plate. I used fresh HC110 dilution B each tim. I also metered with and without the blue filter and they all came out really thin. What am I doing wrong? I have another box of speed plates and will keep trying until I figure this out.

Tin Can
24-Mar-2021, 00:05
Donít use a meter

Learn Sunny 16 and bellows factor

ernie57
24-Mar-2021, 16:25
Donít use a meter

Learn Sunny 16 and bellows factor

Ok. How does bellows factor come into play on a Speed Graphic with plates? I pay no mind to it with film and get proper exposures. My plates are coming out at least 5 stops underexposed. I have been metering at box speed (ISO 25) and at 100 and holding a blue filter over the dome on the incident meter. Thanks

Kiwi7475
25-Mar-2021, 08:31
Ok. How does bellows factor come into play on a Speed Graphic with plates? I pay no mind to it with film and get proper exposures. My plates are coming out at least 5 stops underexposed. I have been metering at box speed (ISO 25) and at 100 and holding a blue filter over the dome on the incident meter. Thanks

Iíd suggest you spend a plate where you point to a uniformly lit subject, even a wall, and make 4 exposures by sliding the dark slide in 1/4ís covering a range of 4 stops around where you think it should be (in other words if you already know itís off by 5 or more stops from box speed then start 2-3 stops more exposure). Use the same time of the day you will likely shoot, approximately.

That said 5 stops is a lot. There has to be something else wrong here. If you swap the plate for film, do you expose correctly or do you get consistent under exposures?

I mentioned earlier that indoors with tungsten or LED I need to adjust the exposure by +2.5 stops, but outdoors during mid day is 0 to 1.5 depending on cloud coverage and time of the year. Itís all by experimentation, there isnít one size fits all.

But try using one plate in chunks as I said to limit the waste of plates.

ernie57
25-Mar-2021, 10:33
Iíd suggest you spend a plate where you point to a uniformly lit subject, even a wall, and make 4 exposures by sliding the dark slide in 1/4ís covering a range of 4 stops around where you think it should be (in other words if you already know itís off by 5 or more stops from box speed then start 2-3 stops more exposure). Use the same time of the day you will likely shoot, approximately.

That said 5 stops is a lot. There has to be something else wrong here. If you swap the plate for film, do you expose correctly or do you get consistent under exposures?

I mentioned earlier that indoors with tungsten or LED I need to adjust the exposure by +2.5 stops, but outdoors during mid day is 0 to 1.5 depending on cloud coverage and time of the year. Itís all by experimentation, there isnít one size fits all.

But try using one plate in chunks as I said to limit the waste of plates.

Thanks. As soon as the sun comes out, I will try this today. I found a vid on YT by Lund Photographic on this same technique for determining exposure for tintypes. My Tmax 100 comes out properly exposed. Iím still learning how the plates work.