Dynax Digital Forums

I am a recent owner of a Minolta Maxxum 7D.  In the course of testing out the camera I have determined that its ability to render accurate colors when shooting in natural daylight is excellent with very little adjustment ever needed.

However, when it comes to shooting under fluorescent lighting it is very "hit or miss" and with tungsten it is not great in my opinion.  This is all of course based on testing done with AWB, Preset WB options, Custom WB experiments, and even manually adjusting the Kelvins.  Therefore, I started to wonder.  What sort of results could I get if I used the Cokin fliters I had that I use for shooting under those lighting conditions with my film SLR's?  Wonder of wonders, I found that I could get more accurate color rendition using them.

To make a long story short, I started out doing the testing with the camera set manually to 5500K.  That is often sited as the default Kelvins measurement for daylight, which of course is what the filters are geared to compensate for when  daylight film is used under the other two types of light source.  (Bear in mind, I am a person who likes "cooler" images more than "warmer" ones.) 

What I discovered (based on the lighting in my home as obviously opposed to that in your's) was that if the Kelvins were set to 4600, and the applicable filter was in place, that I got better color rendition accuracy than if I used the camera's own built-in means for compensation for the given light sourses. 

The 4600 number was the best compromise between the 4900 that seemed best for tungsten and the 4300 that seemed best suited for fluorescent.  (I wanted to find a compromise Kelvins number because I wanted a default setting to use for Register No. 3 which was going to be allocated to indoor non-flash photography.)  (For those who don't understand what a "register" is in this discussion, it refers to a collection of camera settings that can be memorized and recalled in the camera for ease of convenience.  Not all D/SLR's have this option.)

With the filter for tungsten light, I am losing at least 1EV because of its use.  However, since my default ISO setting for this register is 1600, I am not too badly affected.

I am pleased to have discovered that using filters made for film photography may actually make my digital shots better.

Has anyone else experimented in this use of filters too on DSLR's, or seen the same sort of benefits I have by doing this?

Winjeel: I find that I definately get more accurate results using the old Cokin filters.  The surprising thing is though that on another website another photographer was doing the same thing except he was still using AWB with the filters and getting good results.  I tried it, and found that I too got even more accurate results doing it that way.  My experience with my Maxxum 7D has shown that doing Kelvin adjustments or doing custom WB settings just doesn't cut it.

It was explained to me that: "The WB correcting filter can have a genuine advantage in some extreme situations, e.g. where an individual colour channel would otherwise be boosted several stops from the sensor's native WB (as this would introduce noise similar to underexposing and compensating in post processing, and the noise can cause colour shifting). The filter acts as sort of a selective ND filter, which allows for better exposure for each colour channel."

Now, I have to point out that I am speaking about my Maxxum 7D.  In reviews, it has been repeatedly mentioned that color rendition was generally poor for tungsten and fluorescent lit shots with the 7D.  My wife's A100 seems to deal WB-wise with the aforementioned lighting situations much more accurately than my 7D. Therefore, the use of filters may not be necessary at all with that body or other Alphas. 

Winjeel: I'm not trying to convince you.  I don't care if you believe me or not.  I'm just telling you what my experimenting has demonstrated as giving better results IN MY OPINION for my Maxxum 7D.

If you want to see some comparison shots, drop me an e-mail, and I'll send some off to you with explanations as to their settings at the time they were taken.

dandukro@nc.rr.com

No, I don't just put the filters on and leave them on.  They are only used when I am doing indoor ambient light (meaning no flash or studio lighting) photography.

Yes, with the tungsten filter I do lose at least one stop exposure, but since I have no issue with shooting at ISO 1600 or 3200, that is no great loss to me.

Why would you assume the AWB would cancel out the presence of the filter?  One, the AWB doesn't know there is even a filter there (meaning there is no communication between the two).  And two, the filter only affects, in a strong way, a few particular color bands of light and the others are only affected in a very minor way.  Therefore, the AWB is still seeing most of the light as it is coming to it.  The filter just seems do a better job at adjusting color cast than what the camera's computer program can do.  (Remember again, this is on my 7D and under the lighting conditions in my home.)  I have not yet tried this while indoors in the evening in someone else's home.  I may not get the same results.

As for tungsten lighting, don't your home lights use regular old light bulbs?  If they do, there is your tungsten lighting.

Just tried it with my A900, 80B and on auto WB I'm getting a much nicer shot with a cooler more accurate colour. Nice tip!

Winjeel & Acemclynch: Have either of you or your photog pals done any more experimenting with what were discussing here?