How do I slow the camera down?

[RaymondC]

<p>Thanks Paul and your email - appreciate it :-)</p>

<p>I do like the square filters so I can combine with them with graduate filters. <br />Yes, the Singh Ray's are very expensive. If they are the only ones that make reverse grads, grads are not not that bad but $360 is it or abouts for a Vari - HD - eeek (!). You can even get duo or tri filters around $400! At least for the normal grads the Hitech works out ok if a bit more contrast in the filtered areas but their solid NDs are bad, found someone who had one just bad ad mine.</p>

<p>I found this with the Singh Ray Vari-HD:<br /> http://www.flickr.com/groups/neutraldensity/discuss/72157625823550713/</p>

[RaymondC]

<p>Hmmm .... maybe you have a Canon sensor. I heard that someone who used a (I thought) bad Hitech filter, got no cast with his Canon Rebel but on a Nikon D50 got a strong red cast like mine .... which is the same era as both my Nikon D70 and D2h (which both have this strong red cast). I think I will ask a Canon buddy of mine or go into a store and test one or two of my filters out.</p>

<p>Anyone know if film lacks a strong IR filter too .. but certainly goes red on my film.</p>

[mike_halliwell]

<p>Well, I guess the older the camera the less efficient the sensor's IR blocker filter is. That's why those who do IR photography prefer the older bodies or have to mod newer ones.</p>

<p>The different colour casts would be explained by the way the different sensor (either age or manufacturer) 'sees' and records IR wavelengths, ie whether they are interpreted as R, G or B or a combo......ie R + B = Magenta etc</p>

<p>Take a frame, pop a Hot Mirror on aswell and see what, if any, difference there is.....</p>

<p>As the exposure with the ND changes, the proportion or visible to IR will change too = <em>changable colour cast ;-))</em></p>

<p>And of course if that's not enough, changing the time of day is going to change the proportion of IR out there and possibly it's wavelength too. This will really screw around with colours!! Good Luck!</p>

<p>Hot Mirror should fix EVERYTHING.... ;-) <em>maybe.......</em></p>

[mike_halliwell]

<p>Ray, I believe some people use bits of slide film as visibly opaque but IR transparent filters. Can't remember what for, but I<em> think</em> it was to cover the pop-up flash visibly but still trigger the off camera IR sensors on flash guns...</p>

[bob_cook]

<p>Ray - I've been doing this style for years, with both film and digital in DSLR and medium format film cameras. IMHO, the most important filter you should have for including greenery in the frame is a polarizing filter. In any water scene there are lots of reflections, from the surface of the water and from the surrounding rocks and leaves. Use of a polarizer eliminates the reflections that sometimes rob green plants from looking really "green." Plus, the polarizer adds from 1.5 - 2.5 stops, depending on the brand.<br>

The other advice I would offer is to use 100 ISO (or digital equivalent), shoot on an overcast day, and use a tripod. I've never had to resort to a ND filter, and routinely get shutter speeds from 1/2 second to 2 minutes. Usually anything slower than 1/2 second will produce the creamy effect you are looking for.<br>

In years of shooting streams in the Great Smoky Mountain national park there have been many days when it was just too sunny to work. Or, I've had to shoot very early in the morning or very late in the day to get the sun in the right spot. I'm sure you know that sometimes capturing the shot you want is not a matter of equipment, but a matter of patience.<br>

For beach or ocean scenes, the ND filters may be more appropriate.</p><div></div>

[bob_cook]

<p>Ray - I forgot to mention that I was generally shooting at f16.0 or thereabouts. Partly for the long shutter speed it required, and partly for max depth-of-field.</p><div></div>

[RaymondC]

<p>What is a hot mirror?</p>

<p>Well I forgot to try the Hitech on the D90 in the shop. The B+W filter (6 stop) was similar to my D2h both shot at the shop.. I came across this off the B+W site - it does say it gets a warm cast on the 6 stop and says can be remedied with a 486 filter in front. </p>

<p>The samples concur to mine ... <br />https://www.schneideroptics.com/ecommerce/CatalogItemDetail.aspx?CID=679&IID=8110</p>

<p>I didn't try it on a Canon body. Maybe yeah ... as Google goes, those who had color cast maybe it is true - warm cast on B+W particularly with dense filters and maybe the Hitech goes wacko with the earlier cameras. I'll try both filters on someone's Nikon D200 and a Canon 5D II.</p>

[RaymondC]

<p>If anyone still following this. I think it is to do with the particular camera's sensor and/or the low pass filter. What I can say it is bad on the D50, D70, D90 and D2h. I heard the 350D Canon and the 20 and 30D works fine but it's back on the 40D. </p>

<p>I shot some E100G Kodak slide film on my Nikon F100 with the same filters along side my D70. Whilst I didn't shoot any greens, it was just water and rocks. The results were a world apart. I am gonna shoot some greens on a roll of Provia 400F side by side with digital and compare the results afterwards. <br>

<br />You've already seen the digital's results. The film results, well okay there is no such thing as 100% identical color neutral. Ok. But if you used a 2 stop B+W filter you would be hard pressed to note the diff. The 6 stop B+W has a v slight red cast but nowhere as bad as on digital. The Hitech 4 does get a red cast but it's no where as bad as digital. It is maybe less of a cast but it attenuate the reds. Like the rocks and water is still look not the same but still quite natural. </p>

<p>Hot mirror or IR cut filters are pricey. Rather get a newer camera, LOL. <br>

I am thinking that the good filters block out some IR wavelengths.<br>

Compared to film maybe some digital camera models have a much weaker IR filter.<br>

Will post images later when film is processed. </p>

[mike_halliwell]

<p>Of course we're still following this!</p>

<p>I suspect the glass ones cut out more IR than the resin ones.</p>

<p>Hot Mirrors occasionally pop up on the *bay, I picked up a 77mm for £10 ~ $15<br>

There's a 52mm for under £10 (in the USA) at the moment!</p>