Using a wide angle lens in zone testing

[Puma]

I use two lenses in my photography a 24mm made in 1998 and a 50 made in 1958. The contrast differences between them is very great. I've successfully done zone system testing with the 50 and real world zone photography with it, now I think I need to do the same testing with the modern lens to establish correct system speed and development. I used a grey card with the 50 and it was easy because the card filled the frame.

Will it make any difference if I get the 84 degree lens within inches of the grey card? Assuming I can get it without a shadow cast upon it. It seems the only way to fill the frame.

I tried to just use both lenses interchangeably based on the results of the 50 and to my surprise it doesn't work that way. The 50 is very low contrast and the 24 very high contrast. Both lenses are stellar performers but unique in their own way and I want to get the most out of both.

Thanks for your insight,

-Puma

 

[2F/2F]

Hi,

It is a very good idea to test your different lenses when using the Zone System. F stops do not always accurately represent the amount of light that actually makes it through the lens. (T stops do that, and why we don't use them for still photography, I do not know.) There can be differences between lenses based on how efficiently they transmit light. One glaring example that I know of first hand, since I actually did the comparison myself, is the Canon 200mm f/1.8 vs. the new 200mm f/2 IS. The 1.8 is 1/3 f stop faster. But because of the difference in optical design between the two – the new one has IS, for one – the older 1.8 is actually 2/3 t stops faster.

And, as you have seen with your own eyes, different lenses can render things quite differently in terms of contrast.

Just make sure your lens is focused at infinity for the grey card test, and make sure that you are not casting a shadow on the card. It also OK to back up a little if you are having trouble keeping your shadows out of the way. You can take a densitometer reading off of a very tiny area, so backing off a bit won't hurt you. As long as you meter only the card itself, it doesn't matter whether or not it fills the frame.

 

[Puma]

Thanks for validating my thoughts on this matter. The only thing is that I don't have a densitometer, I'm using a Projection print scale and while it isn't as accurate it seems to work. When the grey card isn't at the edge of the frame it poses difficulties but I suppose I could cut the negatives to make it work.

There's a guy in town who has a densitometer but he won't let anyone use it, rent it, pay him, nothing. I hunted far and wide to find one I could use, X-Ray departments, Printers, other photographers and never came across anything I could use.


Sincerely,

Puma