Step Wedge

[Alan Johnson]

A step wedge that downloads in Photoshop and can be printed out is here:
8 bit step wedge � Negatives � AlternativePhotography.com

If I photograph it can I use the densitometer on my Epson V700 to compare the characteristic curves of different developers?
Thanks.

 

[Alan Klein]

What is a step wedge? Can it be used in the digital print process to determine best lighting editing in Photoshop in preparing for the print?

 

[RalphLambrecht]

A step wedge that downloads in Photoshop and can be printed out is here:
8 bit step wedge � Negatives � AlternativePhotography.com

If I photograph it can I use the densitometer on my Epson V700 to compare the characteristic curves of different developers?
Thanks.

you are better off getting a real step wedge from stouffer.com.they are not expensiveand shipping is peanuts.

 

[Alan Johnson]

Alan, the use of a step wedge is described in the link below.
Library

Ralph,
If I get a Stouffer wedge , can I use the Density readings from my V700 scanner or would I need a "real" densitometer?

 

[L Gebhardt]

If you scan the step wedge at the same time (or the same settings) as your negative you can get very close readings with a flatbed scanner. The best way is to take readings with the eye dropper of each of the known steps on the step wedge. Plot the pixel value vs density. Then take your readings with the eye dropper and reference your chart to get the actual density.

 

[Alan Johnson]

Thanks Larry, that should give a good approximation for the density D.
I believe the Stouffer wedges are calibrated in fractions of a stop giving a known value for logE.
Is there any advantage in using a transmission vs reflection Stouffer wedge?

 

[RalphLambrecht]

Thanks Larry, that should give a good approximation for the density D.
I believe the Stouffer wedges are calibrated in fractions of a stop giving a known value for logE.
Is there any advantage in using a transmission vs reflection Stouffer wedge?

I prefer transmission scales because,reflection scales are heavily influenced by glare and flare;it's almost impossible to measure the darkvalues with them
BTW,sve your money forso-called'calibrayed'scales.they are not calibrated,just measured with their, hopefully calibrated equipment.there is no ned for that.you don't need absolute values.their value is that they have known relative densities.that's all you need.that saves a lot of money or buys you a scale in another size!

 

[L Gebhardt]

Thanks Larry, that should give a good approximation for the density D.
I believe the Stouffer wedges are calibrated in fractions of a stop giving a known value for logE.
Is there any advantage in using a transmission vs reflection Stouffer wedge?

Use a transmission step wedge for film (transmission) and a reflective step wedge for reading paper. I've never tried this with paper, but I don't see why it wouldn't work the same. I also don't know if Stouffer sells reflective step wedges.

You can get different density ranges and gradations. The standard transmission one is 21 steps which are .15 density units (1/2 stop) apart. So it covers about a 10 stop range, which is plenty for most uses. There's also a version with 31 steps (.10 density units each).

 

[Alan Johnson]

To backlight a transmission step wedge I have 2 100w tungsten lamps shining on a 2ft square white card and some way in front of that a double thickness of translucent white plastic (from an art shop) in a propped up photo mount. My exposure meter gives a uniform reading within 1/6 stop across the part of the translucent plastic where the step wedge is to go. It is about 1/30 f5.6 EI=100.
It appears to be satisfactory, thanks for all the advice.

 

[RalphLambrecht]

Alan, the use of a step wedge is described in the link below.
Library

Ralph,
If I get a Stouffer wedge , can I use the Density readings from my V700 scanner or would I need a "real" densitometer?

a 'real' transmission and reflection densitometer is a great tool for analog and digital photographersbut not amust!Convenience costs a lot of money but Iwould not like to be without my Heiland.