Multi Exposure as an alternative to ND Filters (Discuss)


Snappyhoffy

Link Posted 14/09/2018 - 13:23
I have downloaded and enjoyed a very good 'Guide' to the K3 "Everything you need to know... and then some." - Yvon Bourque. (http://pentaxdslrs.blogspot.com/)

In this publication there is a suggestion to use the Multi Exposure setting as an alternative to using an ND filter to capture moving water etc. In theory it seems a great work around but just wondered what other views may be out there.
'Life looks simple through a viewfinder'.....then I went Digital!
Keith
K3, DA* 16-50, DA* 50-135, DA* 300, AF360

RobL

Link Posted 14/09/2018 - 13:48
I have tried multiexposure and the results have been a bit mixed as lots of single images merged do not look the same as a smoothed single exposure. The only way it could work is if you make a large number of exposures, say 50 or more, but it is worth experimenting. Downside of course is your shutter count goes up so for that reason if no other I prefer filters, and of course if you are taking landscapes you will probably have an ND grad filter on anyway so easier just to drop in a 6 or 10 stop as well.

alfpics

Link Posted 14/09/2018 - 17:33
There was some sort of discussion on this a while back, but I can't seem to find it. However I have one posted in this thread - no 8 in the thread - 30shots. I agree it doesn't give the ultra smoothness of a proper ND filter, but sometimes this doesn't matter. It can save some time fiddling around getting the filter on to the lens and then trying to frame and focus in almost darkness (although Live View helps somewhat). And of course if you happen to forget to take the filter out with you !

A downside is excessive shutter use as Rob has pointed out.
Andy

Snappyhoffy

Link Posted 14/09/2018 - 18:19
I thought the intention is to add 2 o 3 images not 50. But understand the graduated ND filter comment.
'Life looks simple through a viewfinder'.....then I went Digital!
Keith
K3, DA* 16-50, DA* 50-135, DA* 300, AF360

RobL

Link Posted 14/09/2018 - 22:45
Snappyhoffy wrote:
I thought the intention is to add 2 o 3 images not 50. But understand the graduated ND filter comment.

If you only use two or three you won't get smoothing or blurring, just rather messy unsharpness if that makes sense where moving parts like waves show each separate exposures overlaying each other. Here's one I tried earlier which didn't come out as intended but look at the tree leaves:

Abe_Normal

Link Posted 15/09/2018 - 01:56
Certainly on the KP it's possible to save the aggregated picture as each new image is added, so you can review the sequence later and see how the effect builds up (see below).

I suspect the art lies in selecting an appropriate shutter speed for each shot, determining how long you want to shoot for overall and calculating the combination of interval/number of shots that will achieve this.

Under most circumstances, I expect you'd want the slowest shutter speed possible; I reckon I'd have got a smoother result if I had stopped down to f/11 and 1/10 sec.

F/5.6 - 1/50 sec - ISO 100
I think I had the shortest possible interval between shots, which might be 2 seconds. Cropped from the centre of the images, where most detail is visible.

Number 1

Number 5

Number 10

Number 20


I can't remember if it's possible to save the result as RAW, which would allow more possibilities for editing later.

RobL

Link Posted 15/09/2018 - 07:40
Thatís interesting, Abe, I donít recall the K1 having that option but the blended image is saved as a RAW file. There are three in-camera processing options and I have tried them all but Average works best for me. I have used it with success for interiors using different exposures and flash so that views through windows are correctly exposed as well as the interior. However in the car shot above the sky, which is in every exposure, bleaches the moving roof which is only in one shot for each position. Against a darker background it was no better, I would probably have more success using Bright in a darker environment like dusk and stop-start the roof action for longer exposures.
Add a Comment
You must be registered or logged-in to comment.