Using ND filters to blur motion??

[tyke]

I have seen many superb images on this forum showing the "milky water" effect and have made one disastrous attempt to emulate them!!

I understand the theory, but really don't know where to start, practically. I have read the article by Peter Hill who seems to use "trial and error".

I wonder if someone could enlighten me on the starting point of the process for my landscape images.

Should I begin with a meter reading from the camera, then alter the number of stops of exposure depending on the ND filter in use? or is there another way? I note that Peter Hill uses the Big Stopper, but this is out of the price range of a pensioner like me! I intend to try the 10 stop ND filter from SRB, suggested by a number of people on this forum, which is much more affordable for me.

I apologise for asking what, for some, may be a very obvious and basic question, but I have looked at so many posts to try to find some guidance that I am going cross-eyed!

All help and guidance would be very much appreciated.

[jimsphotography]

Re: Using ND filters to blur motion??

I suspect different people use different methods.
Personally, I set the ISO to the lowest value possible, set my lens to f16 and then read what shutter speed I get. From that I can then make an educated guess ( what is known in physics as a guesstimate ) at how big a density of ND filter I would need to use.
To blur moving water but to retain texture in the flow you need shots of 2 seconds down to 1/8 second - usually 1/2 second is about ideal. This tends to work best on streams, waterfalls etc.
If you want really silky smooth looking water with no texture than anything from 15 seconds to 5 minutes will work. Remember the longer the time the less texture in the water. Why would you want that ? If you a looking for reflections in a lake with choppy waves then you need to smooth out the waves and a five minute exposure will do that.
Ok?
James

[jimsphotography]

Re: Using ND filters to blur motion??

Sorry - I meant to add that a variable ND filter makes a great start. One you have mastered its use and you want to progress to truly top notch quality ( and not everybody does) then you really can't beat the Lee glass ND filters.
James

[Parsen66]

Re: Using ND filters to blur motion??

James has answered comprehensively. It might seem an obvious point from me but remember to focus before applying the ND and move from auto manual focus

[antoeknee]

Re: Using ND filters to blur motion??

Work much same as James. Only been testing my recently acquired 10 stop filter. Use a table I found on web to give me new shutter speed.

I use manual focus and turn off IS.

As I'm not going to be doing masses of long exposure work so decided the Lee was too much so bought a Zomei which is less than half price. Initial tests show exposure about right for 10 stop. Images are a bit warmer but not too bad and easily corrected in LR.

[Tony Hawkins]

Re: Using ND filters to blur motion??

All advise is sound. The only thing I would add would be don't forget to use a cable release, mirror lock up with live view and put a piece of black electric tape (or similar) over the eye piece to stop the possibility of any light getting in via the viewfinder, this is important with very long exposures. A sturdy tripod is a must. If you are including some sky 'a bit of wind is welcome for movement' (that sounds so wrong!) in the clouds but too much wind can be an issue even with the sturdiest of tripods. Lastly, take your time and work methodically which will help you not make the obvious mistakes that we all make!

[antoeknee]

Re: Using ND filters to blur motion??

Yep forgot to mention live view/release. Agree some movement of clouds looks quite nice.

Always wonder about the covering of the viewfinder particularly if using live view and that most of time shots are towards rising/setting sun.

[Les McLean]

Re: Using ND filters to blur motion??

I would suggest getting to grips with the 'milky water' effect without filters first, using light instead, the majority of my slow shutter speed shots of running water were without filters, using low light (particularly towards dusk/sunrise) to create this effect.
10 stoppers are great, but not easy to master (as explained in other posts).
The only other pointer is to expose for the highlights (usually the whites of the running water), its a lot easier pulling the midtones/shadows back in editing, it's almost impossible to replace detail in blown highlights. If you can't meter the highlights, try underexposing from average by 1/2 to 1 stop to get the correct exposure.

[tyke]

Re: Using ND filters to blur motion??

Many thanks to everyone for your valuable advice. Now that I know where to start I can experiment.

Anyone know of any waterfalls in the Skegness area of Lincolnshire??

[rcarca]

Re: Using ND filters to blur motion??

Many thanks to everyone for your valuable advice. Now that I know where to start I can experiment.

Anyone know of any waterfalls in the Skegness area of Lincolnshire??

Lol!!!

At a recent trip to Durdle Door on the South Coast I was greatly troubled by the wind, as I had my less sturdy tripod: big mistake. I also had several elementary fails: I forgot to switch IS off, but fortunately my 24-70 doesn't have IS so I was saved on that one. I forgot to take my release cable, so I set it to a 2 second delay shutter. I also experimented with bracketing at the same time.

Bottom line was that all of those without my Lee Big Stopper were much better than those without! I have some truly awful photographs!!!

Note to self: don't give up just yet!!! More practice required...

Good luck

Richard

[tyke]

Re: Using ND filters to blur motion??

I would suggest getting to grips with the 'milky water' effect without filters first, using light instead, the majority of my slow shutter speed shots of running water were without filters, using low light (particularly towards dusk/sunrise) to create this effect.
10 stoppers are great, but not easy to master (as explained in other posts).
The only other pointer is to expose for the highlights (usually the whites of the running water), its a lot easier pulling the midtones/shadows back in editing, it's almost impossible to replace detail in blown highlights. If you can't meter the highlights, try underexposing from average by 1/2 to 1 stop to get the correct exposure.

Hi, Les,
I did take some shots of East Gill Force, near Keld in Swaledale some years ago. From memory I had to use a shutter speed of 1/2 sec with slow colour film and no filter. I was quite pleased with the results. I am sure I could improve the image with software now available, if only I could find the negatives!!