Three methods of composing images for better science photography Martin Valent National museum – Prague – Czech Republic

Contents 1.Introduction 2.Greater depth of field (stacking images in Z axis) 3.Panoramic picture (merging images in X and Y axes) 4.High dynamic range photography (HDR) 5.Summary 2/20

1. Introduction Problems with photos  narrow depth of field  low resolution  narrow field of view  insufficient dynamic range Solution three ways of stacking images three ways of stacking images 3/20

2. Greater depth of field Problem: narrow depth of field with high magnification – close up photography or microscope photography. Solution: stacking series of pictures with same exposure and varying depth of field. Note: The depth of field shrinks with decreasing subject distance, decreasing aperture value (f-stop) and increasing focal length. 4/20

2. Greater depth of field How to do it 1.Use tripod or stand for exactly aligned images. 2.Maintain same exposure for all images (program M - manual exposure setting on your camera is highly recommended). 3.Take series of pictures with overlapping depth of field. 4.Take the same series of images again, to be sure you have good source photos. 5.Use software like CombineZP to merge pictures into final image with full depth of field. 5/20

2. Greater depth of field How to do it – using freeware CombineZP. 1.New – select images to be merged. 2.Align and Balance Used Frames (Quick) – GO. 3.Select method of stacking – e.g. Do Stack – GO. 4.Save. 6/20

2. Greater depth of field Example: 14 images CombineZP 7/20

3. Panoramic picture Problem: low resolution of images and/or lens causing too narrow field of view. Solution: assembling set of pictures with same exposure and same focal length. 8/20

3. Panoramic picture How to do it (part A) 1.Choose a focal length with minimal optical distortion (e.g. more than 35 mm). 2.Focus on desired subject. After that, it is useful to turn off automatic focusing (AF), by switching to manual focusing (MF). 3.Determine exposure, using the brightest part of the scene. Exposure values (exposure time, f-stop and ISO speed rating) are taken in any suitable automatic/semiautomatic exposure program (usually, the best program is A – aperture priority) and then set in manual exposure program M. 9/20

3. Panoramic picture How to do it (part B) 4.Turn off the camera's automatic white balance and set it to any acceptable preset value. 5.Remove any filters (except UV) from the lens. 6.It is essential that the imaged areas overlap by about 20%. 7.It is possible to take pictures in several rows; the camera can be oriented horizontally or vertically (preferable). 10/20

3. Panoramic picture How to do it (part C) 8.Take the same series of images again, to be sure you have good source photos. 9.Compose images in MS Image Composite Editor. For best results and smaller crop, use tripod or stand, but it is possible to take pictures with camera in your hands. 11/20

3. Panoramic picture resolution 124 MPx 14 source images with resolution 18 MPx 12/20

3. Panoramic picture 29 source images with resolution 24 MPx resolution of raw panorama 458 MPx resolution of final panorama 189 MPx 13/20

4. High dynamic range photography (HDR) Problem: insufficient dynamic range. Solution: merging images with different exposures. 14/20

How to do it 1.For best results, use tripod or stand. 2.Set camera to any program where you can control exposure – the best programs are: A – aperture priority: use exposure compensation; M – manual exposure: vary shutter speed. 3.Take series of identical pictures with different exposures. 4.Take the same series of images again, to be sure you have good source photos. 5.Merge photos using appropriate software. 4. High dynamic range photography (HDR) 15/20

Example: using free program Fusion F1 Images taken with Canon 6D and macro lens Canon 100/2.8 USM 4. High dynamic range photography (HDR) 0 EV +1 EV -1EV -2EV 16/20 HDR image O EV

It is possible to combine all above described methods to create high resolution images with full depth of view and high dynamic range. Follow these steps: 1.Create set of pictures with different exposures, but identical focus distance, focal length and f-stop. 2.Change focus distance, and repeat step 1 with the same exposure steps. 3.Move field of view, and repeat steps 1 and Summary 17/20

4.Combine pictures with different exposures to make HDR slices with one depth of field. 5.Combine (stack) HDR images (step 4) to make one image with full depth of field. 6.Merge photos (step 5) into one panoramic picture. 18/20 3 sequential field of views * 2 slices of depth of fields * 3 different exposures = 18 images stacked together Final image

Download You can download this presentation or contact me 19/20

Links to freeware programs CombineZP – stacking in Z axis MS Image Composite Editor – stacking in X and Y axes Fusion F1 – creating HDR images 20/20

Thank you for your attention! Supported by project of Ministry of Culture of the Czech Republic (DKRVO 2014, National Museum, ) HDR image of Prague Castle