Commercial Ektar at Near-Macro

[Jarin Blaschke]

Hello Hive:

Out of curiosity, I recently mounted my so far unused 14" Commercial Ektar on my new 14x17 camera to find that there was an image over the entire ground glass at infinity! There was even room for rise. I know that just because there is image, doesn't mean there is useable sharp image. However, I don't yet have my 300mm macro (Rodenstock) in the right lens board, so this got me thinking about shooting some portraits and still lifes sooner on the Ektar rather than wait until I can get the Rodenstock to SK Grimes. For those ranges, I'd be back to using the center of the image circle.

How does the Kodak Commercial Ektar perform for 1:2 to 1:1? At probably f/11or /16, possibly /22? Let's say I want an uncommonly sharp portrait or still life with good microcontrast.

Jarin

 

[_T_]

Especially with such a large image you can look at the ground glass and see to some extent how your copy of the lens will perform. There will be some difference between the image on film and the image on the ground glass, and any flaws will be more apparent on the film. But for the most part what you see is what you get.

Also for the most part 1:1 or even 2:1 on 14x17 doesn’t ask much of the lens. I would be surprised if it didn’t perform well, assuming the lens is in decent shape.

That’s like a typical head shot and head and shoulders range.

 

[xkaes]

Another thing to consider will be diffraction, If you are stopping down to get better resolution, that would normally help, but at 1:1, a lens set at f16 is optically like f32. As the magnification increases, the set f-stop should decrease (open up) to retain resolution -- which this type of lens won't "appreciate". But depending on the subject and the amount of cropping it might work fine. Lots of variables. Worth a try????

 

[blee1996]

I don't have direct experience with commercial Ektar, but I enjoy using Tessar formula large format lenses (Xenar, Velostigmat) for close-up shots. Tessars are not flat field macro lenses with even resolution from center to edge, like modern macro plasmats. But for people and still life, the slight curvature and vignetting plus out of focus rendering draw attention to the subject in the center and create more classic 3D effect.

 

[MarkS]

You're going some distance off the map here, so you'll just have to TRY IT.
The CE's were not designed for closeup work, but they are well-corrected Tessar-formula optics, and have proven to be quite versatile. I have used an 8-1/2" Commercial Ektar for closeups with some success long ago, but never the 14".
As noted, depth-of-field and diffraction will be considerations. Since I assume that you'll be contact-printing a 14x17 negative, absolute resolution may not matter that much.
// A great deal will depend on what you define as "good enough", which only testing can answer.//
And apparent sharpness can be affected by your choice of lighting... a question for another day.
Best of luck- and please share your results!

 

[Jarin Blaschke]

Indeed - for diffraction I usually don't like to stop beyond /45 whenever possible, so that seems to put me at /16 to /22, pretty shallow depth of field in 14x17.

I suppose if Karsh used a 14" Commercial Ektar it can't be that bad for close-ups.

If the picture is any good, I'll drop the small fortune to drum scan it.

 

[Dan Fromm]

Indeed - for diffraction I usually don't like to stop beyond /45 whenever possible, so that seems to put me at /16 to /22, pretty shallow depth of field in 14x17.

I suppose if Karsh used a 14" Commercial Ektar it can't be that bad for close-ups.

If the picture is any good, I'll drop the small fortune to drum scan it.

How large do you intend to print? I ask because the diffraction limit at f/45 is around 25 lp/mm. You'd have to print at 42 x 51 to get 8 lp/mm in the final print. 8 lp/mm in the final print is generally accepted as the lowest resolution that's sharp enough at normal viewing distance (10").

Re comments in post #4 above, there are tessars and there are tessars. f/6.3ers, including Commercial Ektars, are better corrected and have more coverage than faster tessars.

 

[Bill Burk]

From an old Kodak Lenses handbook. It mentions your lens but not in detail.

This factual chart seems relevant. If you’re looking for ideas, it suggests you can do macro work. Maybe a portrait of the mermaid figurine from your movie.


For a 4 inch medium format lens: