Photography

• http://www.cambridgeincolour.com/tutorials/digital-photo-editing-workflow.htm - Basic principle
• http://www.cambridgeincolour.com/tutorials.htm
• Darktable overview - http://digital-photography-school.com/darktable-vs-lightroom-does-it-measure-up/

Pentax

Pentax Manual with old lenses

• Set Focal Length, Custom Setting
• use aperture ring, fixed ISO (v. important otherwise wide open)
• use green button to check shutter speed required.