Lane Dry Plates: What is a practical ISO rating?

[Jim Noel]

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]

Thanks. This makes sense and calls for further experimenting.

[Nodda Duma]

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]

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]

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]

Don’t use a meter

Learn Sunny 16 and bellows factor

[ernie57]

Don’t 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]

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

I’d 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 1/4’s covering a range of 4 stops around where you think it should be (in other words if you already know it’s 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. It’s all by experimentation, there isn’t one size fits all.

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

[ernie57]

I’d 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 1/4’s covering a range of 4 stops around where you think it should be (in other words if you already know it’s 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. It’s all by experimentation, there isn’t 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. I’m still learning how the plates work.

[Vaughan]

Hello, I just purchased some of J Lane's Speed plates and while they arrive I am researching everything. The UV spectrum sensitivity is probably a huge cause for exposure errors when using normal (particularly modern) light meters.

My questions is: surely there could be a way to make a light meter with a sensor that is matched to the sensitivity of the plates? I would be surprised if there were no electronics experts here that could come up with something...