Questions re filters for the G system polarizers

G

Guest

Hi -- a few filter questions for the cognoscenti:

1. Is it necessary to make an exposure adjustment to compensate for filter factors when using filters on the G system, or is metering done TTL such that filter factors are automatically accounted for? (How about with Contax SLR's? And for extra points, what about with the Konica Hexar?)

2. With the G system, what sort of polarizer -- linear or circular -- is appropriate? Also, any tips on how to use a circular polarizer with the G? Same question for Contax SLR. What are you looking for when you rotate?

3. I have recently picked up some very reasonably priced Hoya "Super HMC" UV filters, the narrow profile "pro" ones. I suspect that they are superior to the very expensive Contax G filters, but couldn't say for sure. Any opinions?

Many thanks for your responses.

Regards,

Kirk
 
G

Guest

Hi Kirk,

Although I'm often told that people adjust exposure when using a polfilter (even on a SLR), I fail to see why. In fact, I never do and it seems to work fine.

On My G lenses I use a circ pol filter from Kaesemann. Actually the set contains two filters, one to screw on the lens, the other to look through and make the correct adjustment. They both have numbers on the side which makes it pretty straightforward.

Just my 2 cents.

Regards

Raymond Plischke
 
G

Guest

Hi Kirk and Raymond,
For question 1:
There are a lot of argument about adjusting exposure for Polarizer filter (PL). From my research on manufacturer websites, various sources in the web, and my personal experience, the short answer is YES. According to Hoya, the filter factor is to add 2 and 1/3 f-stop. And the B&W is to add 2 f-stops (if I remember correctly). Filter factor is something can not be ignored, especially shooting chrome films (Slides). Although SLR cameras seem to adjust filter factor, but all meter has color bias. The safe side is to test it individually. Check the meter readings before and after putting the filter on. I owned a N1 and have used Contax Yellow, Orange , Red, Green, 81A and 82B filters. The N1 does not seem to adjust the meter reading accordingly on each filter. Since I use the O, R, G filters for B&W negative, and I always bracket my shots, I can adjust the exposure in printing.
I have done a lot of product shoots in the studio with PL to eliminate reflection with chrome films. Adding the filter factor according the manufacturer gives me right on result. When you are shooting negative, you may not notice the difference since the exposure can be compensated (to a degree) in printing. Besides, the camera may compensate the exposure to a degree if not 100%.
For question 2. Generally, circular PL is for auto focus camera. Linear filter does not always work well for auto focus camera.
For question 3. I would buy Contax filters as long as I can afford them. I just love them. I also own a number of Hoya HMC filters. They work well. The Contax PL filter for my 24-85 zoom costs over US $230. The Hoya is over three times cheaper and does the job. Always buy the narrow profile for 24-85zoom if available. Never put more than one filter when using the 24-85 zoom or else vignetting will show up in your film.
Here is my two cents.
Albert
 
G

Guest

Hi Albert,

In my experience the TTL-metering of G-system (well, can only speak for the G2, never used the G1) does compensate the exposure (at least with the filter I mentioned before), so no adjustment is necessary. BTW, I have the same experience with Nikon lenses and Nikon pol filters.

Does anyone know whether a comparable set of pol filters is available for the T3?

As far as I know Contax does not make pol filters for the G or T. I think I read somewhere (forgot where) that they (or Zeiss) follow an explicit policy on this.


regards
Raymond
 
G

Guest

The one exception is the 16 mm Hologon. This lens sits so far back into the camera (about 20 mm) that it blocks the internal meter. This lens meters by a seperate external meter that is not TTL.
 
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