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@Ian - Who's the man? You the man!
At work now, and barely time to skim through what you have written - but I will read and digest it all tonight. Initial thoughts are: awesome write-up. A few people replied to my other thread saying they had recently bought or were about to buy extreme ND's and this will be a great resource for everyone.
This weekend is forecast to be cloudy and windy at times so I hope to make good use of your advice, and have something to post next week.
Thanks, PJ
Posted 33 months ago.
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Wow great write up Ian- terrific tutorial. Need to try this our sometime!
Posted 33 months ago.
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All good stuff Ian. I think it is worth adding a bit more about calculating the final exposure with examples of what the final exposure would be based on an original test exposure result of say 1/60, 1/125 and 1/200 (show your workings for full marks).
I find the most interesting part is the difference between the unfiltered and the 10x.
Have you considered getting any ungrad ND filters for your filter holder, and maybe combining the ungrads with the grads for shots like this? I know you can get an IR to fit the holder on ebay for about £20. That has a factor similar to its packaging and will play havoc with all kinds of things, including focus.
Originally posted 33 months ago.
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leeechy (jkjond) edited this topic 33 months ago.
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PJ from UK
Thanks PJ....I'm pleased that you spotted the thread and hope it proves of some use.
You may find that 8 stops is not enough during the brightest part of the day in Summer, although there's always dusk, dawn and even nightime in brightly lit cities if you have the patience. In winter it should be okay for the whole day.
If you've got one, a simple CPL on top of the nd filter should give you an extra 3 stops (?) - I don't own one so it's just a guess.
Ian
Posted 33 months ago.
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Karthikdv
Thanks.....the filters aren't exactly cheap but they certainly open up long exposure photography if you are into that kind of thing.
Ian
Posted 33 months ago.
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leeechy (jkjond)
Hi John,
The original unfiltered exposure (allowing for ev compensation) was 1/500th second at f11 and iso 200.
Someone on DPR recently posted an easy calculation conversion factor but I find it just as easy counting on fingers and thumbs. A 10 stops longer exposure would be roughly 2 seconds
1/250th -1/125th - 1/60th - 1/30th - 1/15th - 1/8th - 1/4 -1/2 - 1 sec - 2 sec
I often (but not always) find with my B+W filters that they need a bit extra and in actual fact the correct exposure after adding the 10 stop filter was 4 seconds.
Another quick calculation to get the extra 6 stops for the final filter gave me an exposure of 4 minutes.
8 - 16 - 30 - 1 minute - 2 minutes - 4 minutes
If the scene had not been as bright as this I would obviously have ended up with an 8 minute or a 16 minute exposure in which case I could have opened the aperture of the lens up from the original f11 to a setting of f8 or f5.6 to lower the exposure time back to a sensible figure.
(Yes - I freely admit to having adjusted the aperture the wrong way on a couple of occasions!)
Because the long exposure noise reduction effectively doubles the time that the camera is out of action, I usually leave any really long exposure attempts for the last shot of the session.
Ian
Originally posted 33 months ago.
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Ian Bramham edited this topic 33 months ago.
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Thanks for the explaination Ian. I've been following your use of ND filters for long exposure photos and admiring the results. So I recently purchased a filter kit (Cokin z-Pro series) for use with a wide angle lens also recently purchased (Sigma 10-20 f/3.5, that unfortunately had some back focus issues and is being shipped back for exchange).
I was thinking the larger Pro series filter holder may eliminate the vignetting that you have mentioned here when stacking filters, but then it occured to me that because the light must essentially pass through a much thicker filter before it enters the lens, perhaps that alone is enough to create a strongly vignetted image even before any shading effect from opaque filter ring comes into play. Additionally, it seems that more light will be reflected from the surface of the filter due to the lower angle incidence at the perimeter of a very wide angle lens. I guess I'm wondering if vignetting can really be eliminated or really reduced much even with the larger filter size. I certainly am into more expense attempting to circumvent a problem that may be unavoidable.
Until my replacement lens arrives, I have an adaptor ring for my 16-85 and can try shooting wide with the filter set. I am curious as to Leeechy's question, stacking ND Grads and NDs and wonder if you have had any success with that technique. Also, I saw a video clip of a photographer using his ND Grad filter free-hand, doing an exposure dodge to blend the gradient edge and wonder if this is something that you have tried. I guess there are a lot of experiments in my future ! Thanks for any advice, from anyone.
Posted 33 months ago.
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leeechy (jkjond)
"Have you considered getting any ungrad ND filters for your filter holder, and maybe combining the ungrads with the grads for shots like this? I know you can get an IR to fit the holder on ebay for about £20. That has a factor similar to its packaging and will play havoc with all kinds of things, including focus."
I haven't yet tried combining these circular screw-in B+W nd filters with my Cokin rectangular nd grad filter.
The vignetting on the 10-20 lens would be something to behold!
I think the next filter I get will be one of the bigger Lee rectangular nd grads to replace my small p series Cokin one.
The Cokin is very convenient though as it all fits in my smallest camera bag which takes the D40 and one lens + both B+W filters, mciro fibre cloths and the Cokin nd grad.
Ian
Posted 33 months ago.
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chris aka phlyfisher
"I was thinking the larger Pro series filter holder may eliminate the vignetting that you have mentioned here when stacking filters, but then it occured to me that because the light must essentially pass through a much thicker filter before it enters the lens, perhaps that alone is enough to create a strongly vignetted image even before any shading effect from opaque filter ring comes into play. Additionally, it seems that more light will be reflected from the surface of the filter due to the lower angle incidence at the perimeter of a very wide angle lens. I guess I'm wondering if vignetting can really be eliminated or really reduced much even with the larger filter size. I certainly am into more expense attempting to circumvent a problem that may be unavoidable.
Until my replacement lens arrives, I have an adaptor ring for my 16-85 and can try shooting wide with the filter set. I am curious as to Leeechy's question, stacking ND Grads and NDs and wonder if you have had any success with that technique. Also, I saw a video clip of a photographer using his ND Grad filter free-hand, doing an exposure dodge to blend the gradient edge and wonder if this is something that you have tried. I guess there are a lot of experiments in my future ! Thanks for any advice, from anyone."
Hi Chris,
The nd filters I'm describing in this thread are the circular screw in type:
I also have a nd graduated filter which is rectanguar. It's a P series Cokin with a single slot wide angle holder. I think the Z series one that you've got sounds a lot better as it's bigger allowing for more adjustment in the exact placement of the graduation line.
I haven't yet tried combining the two types nor have I tried holding the nd grad filter free-hand. The P series filter holder is so easy to use that I'd rather use that and leave both hands free for holding the camera.
Ian
Posted 33 months ago.
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Ian Bramham
Great tutorial Ian, I read it with interest. As I read, I did the time calculations in my head (well, using my fingers just like you), then compared them and came to the correct result in the 10 stop calculation. However, in the final 6 stop calculation my result was 2 minutes rather than your 4. It seems you have 7 stops there, or am I missing something?
Thanks again,
Joe
Posted 33 months ago.
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junksecret
Thanks Joe!
Re the calculation, I mentioned in the text that I sometimes need to add a stop of exposure using these filters and that I adjusted it up to a 4 second exposure after testing with the 10 stop filter in place.
The 4 minutes is therefore calculated with 4 seconds as the starting point rather than 2 seconds.
Ian
Originally posted 33 months ago.
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Ian Bramham edited this topic 33 months ago.
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Thanks Ian for the great tutorial.
Does anybody know if there is a lot of light leakage with cokin (or similar) filters which would effect the exposure calculation?
JohnB
Posted 33 months ago.
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Thank you Ian for the follow up, I'll look into the screw in filters as well. I have a decent screw-in CPL and will try to use that in conjunction with some of the filters I have for a couple more stops of light reduction.
Posted 33 months ago.
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This is an intriguing idea Ian. As you know, I love to do long exposure night photography. Exposures of 30 seconds do a good job of streaking clouds and moving rivers. Do you need such long exposures to get a nice effect during the day?
Morris
Posted 33 months ago.
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Ian, excellent guide. I've been watching the long exposure stuff for a while and pricing the B&W and similar filters, all around £80 it seems.
Tries a 3 stop ND with an IR72 and a CPL for an experiment just to see what level of noise would be apparent before I take the jump.
You don't seem to incorporate a noise step so presumably the in camera LE noise reduction is sufficient.
Photos lovely as usual.
Posted 33 months ago.
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Thanks for the tutorial, Ian. I've seen your results before, but I had no idea just how much difference the long exposure makes on the clouds. It's terrific to see the "before" shots.
I just looked at a couple of online stores for these filters, and their descriptions are pretty confusing. I found the B+W Filter Handbook to be helpful in decoding some of the listings.
Originally posted 33 months ago.
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Ben_D edited this topic 33 months ago.
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This is superb stuff Ian, thank you.
Posted 33 months ago.
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sicherheit
"Does anybody know if there is a lot of light leakage with cokin (or similar) filters which would effect the exposure calculation?
"
Sorry, I've no experience of using extreme rectangular nd filters (are there any?)......when you see just how dark my 10 stop circular nd filter is I don't see how a rectangular one would work due, as you say, to problems with light leakage.
Ian
Here's how black a 10 stop is:
Posted 33 months ago.
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Morris0
"Exposures of 30 seconds do a good job of streaking clouds and moving rivers. Do you need such long exposures to get a nice effect during the day?
"
Hi Morris,
The main problem I have when taking these long exposures in the daytime is that I only have the two filters - a 10 stop and a 6 stop so my choices of exposure time reduction are obviously limited to not very subtle steps of 6 stops, 10 stops or 16 stops.
6 stops is never enough for smearing cloud movement in full sunshine in my experience.
10 stops is sometimes enough but usually means using a small fstop like f22 where diffraction is kicking in and it also usually needs high winds where my tripod isn't always up to the job. This photo below was a 1 minute exposure at f22 in winds so strong that my tripod was vibrating like the strings on a harp!
Here's a few more examples at differing combinations of filter and f stop:
- 6 stops at f8 (great for waterfalls in bright sunshine where an exposure of around 1/10th second is the target)
- 10 stop
As you say, sometimes 10 stops is enough even on a bright day to achieve the 30 second exposure you mentioned but to my mind it gives a less ethereal effect to the clouds than one of several minutes.
It all depends of course on how fast the clouds are moving
This one is 30 secs at f16 using just the 10 stop filter but I don't like the effect as much as one of several minutes as I find the clouds competing too much with the bridge for attention.
Originally posted 33 months ago.
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Ian Bramham edited this topic 33 months ago.
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Bender's Better Brother
"I've been watching the long exposure stuff for a while and pricing the B&W and similar filters, all around £80 it seems.
Tries a 3 stop ND with an IR72 and a CPL for an experiment just to see what level of noise would be apparent before I take the jump.
You don't seem to incorporate a noise step so presumably the in camera LE noise reduction is sufficient."
Thanks!
Yes, I always aim for the optimum lowest iso on my D40 which is iso200 and I always enable LE noise reduction which seems to work very well.
I still have a lot to learn with all this but in my experience noise is introduced in 2 main ways when processing these images and converting them to B&W:
1 - the blue channel - Mess with it too much during the conversion to mono and your photo can end up with with strong clumpy looking noise grain
2 - The stage of adding contrast is key and I process my photos as 16 bit Tiff files. The added bit depth really helps in avoiding banding and posterization as well as giving a more subtle result.
Originally posted 33 months ago.
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Ian Bramham edited this topic 33 months ago.
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Ben_D
Thanks very much Ben!
Ian
Posted 33 months ago.
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garyking
Cheers Gary!
Ian
Posted 33 months ago.
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Ian Bramham Sorry, I've no experience of using extreme rectangular nd filters (are there any?)......when you see just how dark my 10 stop circular nd filter is I don't see how a rectangular one would work due, as you say, to problems with light leakage.
Ian, there are filters available from Hitech ..
www.formatt.co.uk/stills-filters/filters/standard-n-d/sti...
I have their ND Grad kit which I use with a Cokin P holder but I was thinking of purchasing a couple of the standard ND to try hence the question. The thing is I can get three for the price of a single B&W 10 stop which would enable me to experiment a bit with long exposure. Could end up as a false economy :-)
From your experience would be a flexible range of stops?
Thanks, JohnB
Posted 33 months ago.
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It is worth noting that noise reduction is camera specific. The 300 can destroy fine detail by using noise reduction so I only use it for really long stuff and not always happy with what it does. It may well be a difference between CCD and CMOS sensors, though that isn't something that I dwell on. As with so many nuances of cameras, it is one of those areas that you need to experiment with using your own camera and find what suits your taste.
Meanwhile, 16 bit is a no brainer. I resisted it for ages, but shooting 14 bit in camera and processing 16 bit makes a huge difference to image quality - let the jpg shooters argue their case, but when it comes to quality, they are wrong.
Posted 33 months ago.
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Great thread
first an observation. The exposure needed to blur the clouds will also depend on focal length. A 10mm lens will have half the movement within the frame of a 20mm lens
Secondly didn't you start with a cheap ND filter? 7-day shop do one for under 20 pounds. In what way is a more expensive filter better?
Thanks again its been very interesting
Posted 33 months ago.
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sicherheit
"From your experience would be a flexible range of stops?"
It's difficult for me to give any advice on the rectangular (non grad) type nd filters as I've never used one.
Recommending an ideal set of nd filters for this type of daytime long exposure photography:
Part of the problem is that wide angle lenses like my Sigma 10-20 don't really like multiple stacked filters and will vignette madly at the wide end. You can see the typical shape of the vignette on these 2 pics where I used both my nd filters to get 16 stops:
f/5.6, 4 minute exposure
f/4.5, 4 minutes
You can obviously work with the vignette as I've tried to do with those 2 photos but fundamentally it would be ideal to have a single nd filter giving 13 stops - a light reduction which would be ideal for most summer daytime long exposure photography in the UK (fine exposure control being via aperture)
B+W used to make one of 13 stops and I wish I'd bought one when they were freely available as I think they've discontinued it now and I can't find one for sale - I haven't tried Ebay yet though.
I'm happy with the 6 and the 10 stops that I've got and combined they obviously give me 16stops you've seen on many of the photos on this thread. There's no vignetting with longer lenses by the way and they work well with both my 16-85vr and 70-300vr nikon lenses via a cheap 77mm to 67mm step-down ring.
I've been thinking of also getting a CPL which I believe also gives a light reduction in the 2 to 3 stop range which I could use with my 10 stop to get to the 13 stops that I mentioned.
In summary if I were buying a new set now I'd get a 6 stop, a 10 stop and a 13 stop (if I could find one)
Ian
Originally posted 33 months ago.
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Ian Bramham edited this topic 33 months ago.
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leeechy (jkjond)
"It is worth noting that noise reduction is camera specific. The 300 can destroy fine detail by using noise reduction so I only use it for really long stuff and not always happy with what it does. It may well be a difference between CCD and CMOS sensors, though that isn't something that I dwell on. As with so many nuances of cameras, it is one of those areas that you need to experiment with using your own camera and find what suits your taste"
Thanks for pointing that out John.....I keep forgetting about the variability of the effect of these features between cameras.
Posted 33 months ago.
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John Clinch
"first an observation. The exposure needed to blur the clouds will also depend on focal length. A 10mm lens will have half the movement within the frame of a 20mm lens
Secondly didn't you start with a cheap ND filter? 7-day shop do one for under 20 pounds. In what way is a more expensive filter better?"
Thanks John!
I'll have to think about that first paragraph statement of yours as it's not something I've considered before. I normally go with the widest angle that I can get away with in order to exaggerate the perspective.
These B+W nd filters are the only ones I've used (apart from my rectangular cheap Cokin nd graduated 2 stop one)
When it comes to nd filters from what I've read, the more expensive ones are better at avoiding colour casts - ie they have more of a neutral effect on colour.
I've also read reports from photographers using cheaper circular filters that sometimes they get stuck on the lens due to poorly manufactured threads.
Ian
Posted 33 months ago.
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cheers Ian
I hadn't considered that a cheap filter might wreck more than my photos. A permanent 8 stop slowing of my lens may not be ideal!
Posted 33 months ago.
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Thank you Ian,
Your fine examples of faster shutter speeds explains the issues well. There are a lot of factors to consider when doing long exposures.
Depending on your lens, you may be able to stop all the way down without quality loss. Everyone should do experiments with there lenses to find the settings to avoid. For a tripod in the wind, have you tried hanging your camera bag under it to add mass to dampen the effects? I always do this for long exposures and it works wonders. One time I was out in 40 MPH winds taking night time long exposures and the bag was swaying back and forth. I watched this and wondered how can this be good?
D70s + 24-120 VR @ f 18, 20 seconds
It appears that humidity is the only thing that effected sharpness of the distant buildings.
I hope you don’t mind my posting a photo in your thread.
For me, the hardest part of this type of photography is the waiting around. 30 second exposure followed by 30 seconds of the camera saying “JOB” while it runs noise reduction. Do you bring a chair and book for your long exposures?
Morris
Posted 33 months ago.
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Karthikdv 
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