align-toparrow-leftarrow-rightbackbellblockcalendarcamerachatcheckchevron-downchevron-leftchevron-rightchevron-small-downchevron-small-leftchevron-small-rightchevron-small-upchevron-upcircle-with-crosscrosseditfacebookglobegoogleimagesinstagramlocation-pinmagnifying-glassmailmoremuplabelShape 3 + Rectangle 1outlookpersonplusImported LayersImported LayersImported Layersshieldstartwitteryahoo

More in HDR: 1 EV, 2 EV or 3 EV spacing

From: Guy H.
Sent on: Sunday, December 11, 2011 8:17 PM
At our last meeting we reviewed a picture I took of the holiday lights in front of my house.  There were 15 pictures ranging from 240 seconds (4 minutes) to 1/15 seconds 1 EV apart.  The question was whether 1 EV spacing was really necessary.  That is an excellent question.

To answer that question I reprocessed those images at 1, 2, and 3 EV spacing using Photomatix and Nik HDR Efex Pro.  The results are posted in the "Holiday Picture Examples" gallery.  With Photomatix, the difference between 1 and 2 EV spacing is insignificant in my view.  At 3 EV spacing some of the texture detail is lost in the tree trunk and the bricks readily seen looking at the full sized 2000 x 2000 image.  This can easily be fixed by blending the offending parts with one of the suitably exposed shown in the 6th image.  In this case I layered the images with a 4 second and 30 second exposure on top of the HDR image.  A black transparency mask was added making the layers totally transparent.  The adjustments were added by using a white, soft brush shown below.

Nik HDR Efex Pro did not have this problem with 3 EV spacing.  With these pictures it was easier to create good images with Nik's product.



In the case of the image below, I didn't pay attention to the standing fish signs.   Consequently the fish signs are seriously blown out.  If I had paid attention to the over exposed blinkies of the fastest shutter speed I would have taken another faster shutter speed sequence. Another feature was the tree trunk lights were blinking.    So the three lowest exposed pictures had no lights.  This resulted in unnatural black holes in the middle of the bright lights.  My first take was to put a white layer mask on the HDR layer  then paint in the white light below.  That was tedious.  After a few lights I decided to use the blend mode to blend into the underlying layer.  That worked well for the trunk but then all the over blown fish signs came through.  Hence the layer 2 where Black was painted to cover up the blown out fishes. Layers 3, 4, and 5 were from different exposures to darken the sidewalk, trees, and part of the grass to help draw attention to the lights.  The big problem with this image was the lowest exposure was still at least two or three stops to much.   This is a good example of what not to do and the post processing required to help it.

What all this proves is that if you go to enough photoshop user seminars eventually you will get to be just as sneaky as they are. 





All the images in the examples last Wednesday used seven exposures 1 EV apart.  At an ISO of 10,000 the sensor has a range of about 8 EV rather than 12 EV at ISO 100.  This gives a total range of 8 + 7 = 15 EV.  If I used three images at ISO 100 with 2 EV separation I would have 4 + 12 = 16 EV range and undoubted a much better picture. 

After our tour last Wednesday Ed and I speculated that there would be even more lights by next Tuesday.  I had an occasion to visit Deerfield last night.  Some of those homes have gone over the top!  We will get some spectacular pictures.  This time I will bring my tripod!


Thanks . . . Guy











This email message originally included an attachment.

People in this
Meetup are also in:

Sign up

Meetup members, Log in

By clicking "Sign up" or "Sign up using Facebook", you confirm that you accept our Terms of Service & Privacy Policy