ND3 filter removing objects in motion

[Joan]

Nothing new, but I enclose a couple of pictures taken so as to illustrate the use of ND3 filters and long expositions (30 seconds in this case) to remove non steady objects in pictures (filter used: Haida 1000x Pro II ND3 filter)

https://www.flickr.com/photos/joanilari/16235142037/

https://www.flickr.com/photos/joanilari/16419286191/

My next project will be to shoot at places normally full of tourists so as to get images without people. In this case I plan to use longer exposition times.

[Manfred M]

Joan - your links are not working.

[Joan]

Oops ! Sorry !

Let me try again:

IMG_2517.jpg by Joan, on Flickr

IMG_2515.jpg by Joan, on Flickr

[Polar01]

As Manfred has stated the links to your flickr are not working, it would be much better if you posted the images here instead of having us go to flickr to see them.
As for your next project I suggest that you try 6 minutes as that will almost get rid of people and allow you to get enough detail in the object that you are shooting.

Cheers: Allan

[Joan]

I hope now it's ok ... :-((

[jcuknz]

Yes Joan it works and most interesting to see an example of what I 'knew' but never practiced or seen

[William W]

Really impressed with that example and it is a timely post too – I have just sent the link of this thread to three students of mine, as we were discussing exactly this technique last Friday!

***

An interesting side note – I think that the filter you used should be labelled “ND3.0” (not “ND3”)

The ‘point zero’ in the nomenclature is important, because it designates the optical density of the filter is: “3.0”.

There are different numbering systems for ND Filters, which can cause confusion: I expect that your filter attenuates 10 STOPS, which means that is an:

“ND1024” indicating the equivalence transmission of 1/1024th of the lens opening.
“ND 3.0” indicating an optical density of 3.0

A ten stop ND Filter is often labelled “ND1000”

***

. . . As for your next project I suggest that you try 6 minutes as that will almost get rid of people and allow you to get enough detail in the object that you are shooting.

I agree with the Shutter Speed indicative to make people “invisible”.

But I want to comment that I have had difficulty getting to near 1 minute on a sunny day with only a ten stop filter with digital cameras that have ISO 100 available.

Ten stops from 6 minutes is . . . 3m; 1.5m; 45s; 25s; 13s; 6s; 3s; 1.5s; 0.8s; 0.4s

At F/32 (if the lens has that as a Minimum Aperture available), we are about 3 stops over exposed for front-lit sunlight.

Moral to story – if you only have a "Ten Stopper" – choose an overcast day to get to 6 minutes.

WW

[Richard Lundberg]

Interesting technique, I wonder if it is used in movies, for example a sci fi aftermath thing where everyone has vanished and nothing is moving.

[Stagecoach]

Excellent example of this procedure Joan, I look forward to your further endeavours with people.

[Polar01]

Well William I have to agree, however you see I use the Lee big stopper so I have the Lee holder (actually 2) one is setup with 2 slots and the other with 3 slots, so you see I can I can drop a 4 or a 3 stop in front or even my backup big stopper. I got a second one a few years ago when I wait time was like 8 months, better wait times now. So I do not have to worry about that front-lit sunlight.

Cheers: Allan

[William W]

Crikey - a possible total 24 stops using the three slots - the AF would have a lot of fun with that !

I'll get back to you about the Shutter Speed you can attain - actually if any of you three students read this you can tell me the possibilities at F/22 and ISO 100 when we meet on Friday - and you might also research "Reciprocity" and if (and how) it applies to long exposures with digital sensor cameras.

Cheers back to you, Allan.

[Polar01]

William no problems with AF as I focus first, I use a back button to focus set to continuous focus release button now focus locked, then slip the filter holder onto holder ring already mounted on lens. Nice and easy.

Cheers: Allan

[ajohnw]

This reminds me of taking a very long exposure of the Arc de Triomphe at night on low ISO slide film. Cars disappear but not the lights. A few Parisians that just had to stop in front of the camera and pull strange faces did. I just glared at them, helped move them on. I just took a reading and did some sums in my head. The exposure was perfect. I sometimes get the impression digital isn't so predictable.

On posting this sort of thing I too would prefer people to post on here and at larger size. 1200 px wide allows technical aspects to be judged more easily. These could be saved to other accounts as well with hardly any difference in the time it would take.

John
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[Joan]

This reminds me of taking a very long exposure of the Arc de Triomphe at night on low ISO slide film. Cars disappear but not the lights. A few Parisians that just had to stop in front of the camera and pull strange faces did.
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I guess that the darker the moving objects with regard to the background and the shortest the time they stay in the image, the better the results. Cars with lights in the dark are bad candidates to disappear with this method.

I enclose a second image that I took in the same place with the same exposure but with worst results: here the "flare" of some ghost truck or car can be appreciated on the right lane...

IMG_2511.jpg by Joan, on Flickr

I guess that the longer the exposition the better the results because the less the probability that some moving object may remain static (that is, visible) for the full time of the picture.

Next week-end I hope that I will have some time to take some pictures of some crowded place with the big stopper to check the results.

[Polar01]

Joan what you see here is tail lights as probably the car or truck was applying brakes to take the off ramp. Longer can be better, however if the conditions are not right (getting darker) then rear and/or tail lights will appear as they are stronger than the natural light so greater the chance of those lights showing up.

Cheers: Allan

[William W]

Sorry for any confusion, my comment about the AF was my attempt at wit.

[proseak]

An alternative is to take a series of shots, and then stack them in "Median" mode.

Here's one I c alled "rush hour";

http://i61.tinypic.com/jqmdy9.jpg

[Polar01]

William sometimes it not you, its them (me). I just don't pick up on things, I have seen your writing to know better , but just missed it. I was wondering about that comment "What", was going through my head thinking he can't possibility believe that the AF would work with 24 stops of neural density on it.

Cheers: Allan