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Method for LCC capture

markymarkrb

New member
I have heard from many that they take their LCC capture +2 stops their capture to get the best results. I am still trying to figure out the best workflow for using the ALPA FPS and was wondering if people do this extra 2 stop adjustment typically by aperture adjustment or by shutter speed for their workflow?

Thanks,
Mark
 

torger

Active member
I don't have an ALPA FPS but I can say adjusting aperture is no good as it affects the color cast, vignetting and any dust spots captured. Adjustment in shutter speed is what you should do and keep the rest of the settings the same.
 

dougpeterson

Workshop Member
Ideally, don't change aperture as this effects light fall off and dust correction which is corrected by LCC.

2 stops is typically about right. However it depends on if your subject matter and lens are in the same light. If you're standing with your back to the sun or standing in shadow shooting out into Daylite then you may need more. If you're standing in daylite shooting out into shadow then you may need less.

The goal should be an LCC which is well exposed - around middle gray or, ideally brighter, while not clipping any highlight values at all. The highest priority should be assigned to not clipping any highlight in the LCC because that will have significant impact on the quality of the correction. Underexposing the LCC will have some modest impact on the quality of the correction, but (and feel free to try this some time) you can vastly underexpose the LCC and still get a pretty decent result.

Your dealer can help step you through the nitty gritty or you can search the archives here as there have been extensive discussions.
 

gerald.d

Well-known member
The nice thing about the FPS is that you can use the bracketing to set up the LCC shot automatically :)
 

weinlamm

Member
I'm not sure about the reason of the "+2 stops" you can hear everywhere.

Doug explained that the need is "well exposed" picture. That's a thing I would understand, too.
But then you have to have a look first on your calibrator-tool - and take some pictures like here:
Universal Lens Calibrator

I don't use mostly the Phase One Set - I mostly use a "normal" milk glass - a kind of plexiglas (not sure about the real word in english); 2mm strong.
With this I had the advantage, that it's very cheap and I could buy it in different sizes (only 1,- € per piece) - and I don't lose too much light.
I tested it and it must be round about 0.5 stop. So the biggest advantage for me is, that I don't need to extend my time for taking my LCC-picture.

Sometimes I have to double the time - but mostly in direct sun or any similar situation. Otherwise not - and that's a big advantage.
If you have to change your time from 1/125 to 1/30 - it's not a real problem; very simple on the tech-cam, too. But if you have to go from 2 sec. to 8 sec. it's not fun and eats much time, if you want to make a LCC-picture for each picture.
Perhaps with newer 'high-Iso-Backs' you don't have the need for such long times - but I have a Leaf-Aptus with Iso25 and in 'not too good weather' you have to use long time. :rolleyes:
 

gerald.d

Well-known member
I will attempt to figure the bracketing out then. That sounds fantastic.
It's really simple - set the camera to take one bracketed shot at +2EV, and set the delay between bracketed shots to however long it takes you to get the LCC plate in front of the lens.

Kind regards,


Gerald.
 

weinlamm

Member
Thanks for this hint!
This could help, if the exposure-time is up to one second. If it's longer on a tech-cam you have to use T- or B-mode and with this you have to count the seconds for yourself.

Perhaps I have one day the time to check if the original Phase One Kit is really better than my Plexi. :rolleyes: Until today it's for me good enough with the Plexi - and especially better for my handling. :)
 

miska

Member
I'm wondering why nobody has built a little gizmo, which illuminates the LCC screen (uniformly of course). If you want to make long exposures, adding 2 stops of exposure could be hard. An illuminated LCC screen would solve that...
 

torger

Active member
...or why Schneider/Rodenstock don't have lens caps that could double as LCC. There are a number of workflow improvements that could be made in terms of LCC but it seems like the manufacturers pretend like it's not desired.
 
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