Pentax Digital Spotmeter or Zone VI modified?

[severi_salminen]

(Sorry for multi-posting, but I thought you guys have the knowledge

for this)

 

Does anyone know what is the REAL difference between Pentax Digital

Spotmeter and Zone VI modified version? I know what is said in the

product description, but I was wondering if anyone has really tested

those side by side and found any significant differences (accuracy,

flare, usage with filters...). I do B&W photography.

 

Someone once said that they have been tested in "Controls of Black

and White Photography" by Richard J Henry. Does anyone have the book?

[donald_miller1]

Having had the experience of using an unmodified Pentax digital and then using the same meter after modification by Zone VI, I feel that I am qualified to speak to the question that you pose.

 

The modifications that were performed by Zone VI amount to the addition of filtration which allow the meter to interpret light consistant with the spectral response of panchromatic film. The addition of baffling further enables the meter to be more discriminating. In other words, the meter is not affected by adjacent bright light sources to the extent that other meters are.

 

The bottom line...Does it enable one to do better black and white photography? In my experience, that is certainly the case. The most notable difference is in green pine foliage, which always used to render lower in actual negative density then what I metered it. The reason being that the meter when unmodified was being affected by the large IR reflectance of the foliage and the film was not exposing to the IR at all. Since the modified meter has filtration to limit the meters response to IR radiation, the exposures are more in keeping with the desired tonal placement. I hope that this provides you with the answer that you requested. Good luck in your photography.

[neil_poulsen1]

Take a look at this thread for his comments regarding the Zone VI modified meter.

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=004P7P

 

In case you have further questions, I have the book.

[william_marderness1]

I have used the unmodified and the Zone VI modified Pentax Spot meters, and the modified meter is better. It is more accurate when metering through filters. When metering through a 25 filter, the unmodified indicates a filter factor of 4x, which is wrong. The modified meter indicates a filter factor of 8x, which is right. I also tested the meters' sensitivity to IR. Both have IR sensitivity, but the modified meter is less sensitive to IR.

[kcrisp]

Just a comment on William's post, I have found that the modified meter does meter accurately through most filters. I have never done a side by side comparison so can only say the modified Pentax meter has worked well for me. My experience (confirmed by others when this topic comes up from time to time) is that a reading through a red filter will not be accurate and will underexpose by at least two stops. This was true of the analog modified Pentax I no longer have and the current digital one. Both have been calibrated by Calumet and, later, Mr. Ritter and both had this problem. I now meter with no filter and then apply the filter factor on those rare occasions when I use the deep red filter.

[c_p_goerz]

One little titbit of info I was once given by one of the Zone VI chaps was the identification of a modified and unmodified meter. As you know Zone VI sold the stickers to place on a meter to make them easier to read and as a result many meters may look like a modified version but aren't. Take the meter and look at it from the lens end, the colour of the image from the viewfinder will have a slight blueish look, a non modified meter will have a magenta one. Its slight so may not be the most accurate test but if you are looking for a modified meter then compare it with your own unmodified one. Hope that helps someone.

 

CP Goerz.