Ulton 35/1.7 sharpnes at f16

[Assaf]

Hi guys,
I recently bought an M6 and attached an Ultron 35/1.7 to it.
It's the first "real" RF camera and lens that I'm using so I'm a novice, but I'm trying to study it thoroughly. Especially the precise effects of the aperture and the focusing distance.

I did some low light shooting in open wide lens, and I think I'm begining to understand how it behaves there. I also ran a test film and the lens seems very sharp and the RF accurate.

One thing I still don't understand is how the picture should look like shooting with closed aperture and hyperfocal distance setting.
The hyperfocal distance according to the DOF scale is a bit more than 2 meters (anybody knows the exact distance?)
Now, using it the image at the focal plane seems sharp but the rest of the picture looks a bit soft.

Can someone explain to me how pictures should look like in this setting? Any examples?
Do you open the lens (meaning slower film and faster shutter) while shooting in daylight? Do you measure distance at your object or just use hyperfocal distacne?

Many thanks for your answers
Assaf

 

[Epimetheus]

Here is a pretty good explanation: http://www.great-landscape-photography.com/hyperfocal.html

 

[markinlondon]

Here's a DOF chart.

http://www.dofmaster.com/charts.html

 

[laptoprob]

Different aperture and shutter speed give all kinds of different effects. Both in depth of field and in sharpness (or quality of unsharpness). At f16 I think diffraction will kick in, giving another effect. Light will now creap around corners, so a dark subject to a light background will get some kind of halo-overexposure on the edges. If you don't want that, don't use f16.

 

[rogue_designer]

How are you determining sharpness? Reviewing prints? Scans? There will be some decrease in sharpness throughout the range, just because of how DOF works (circles of confusion). However it should be "acceptably" sharp to the eye in prints at normal viewing distances.

 

[Never Satisfied]

Hi Assaf, I have a 35mm f1.7 and its optimum performance IMHO is at f8. The DOF at f8 is huge, unless you're shooting a minimum distance I would think most things should be sharp, f8 should give you sharpness from 2m until nearly infinity.
Cheers Andrew.

 

[Assaf]

Hi guys,
thank you for your answers.

Rogue - I determine sharpness by looking at scans taken at 1600dpi and blowing them up. I think that dark room prints usually look sharper.
It also depends on the film and its processing.


Markinlondon and Epimetheus - thanks for the references. However something doesn't make sense to me - they first referenes says that the hyperfocal distance for 35mm is is about 3 meters (10feet). However putting the 16 notch at infinity in the Ultron yeilds a focus in between 2 and 3 meters (7-10feet). I think that putting the focus too cloes is my problem, but what am I doing wrong?

Never satisfied? can you answer that? also - the lense back focuses a bit at infinity, it makes sense for an screw mount lens but should it really be this way?

Another one - I would use f8 in daylight, however, many times I use TX 400 as an all purpose film. In broad daylight at 1000 speed I can't open more than 11 (according to Sunny 16)
.
Slower films are also sharper... you can't beat them all 🙂

Many novice questions and many answers. I hope you don't mind answering
cheers!
Assaf

 

[markinlondon]

Different lens manufacturers have different ideas of "acceptably sharp". Also the formula of the lens will give variations in the depth of focus available. The chart I linked to is derived arithmetically and gives a theoretical value but one that is close enough to use as you've proved.
Do by all means shoot slower films, the old wisdom in 35mm photography was that you should always use the slowest film you could for the job. This would give you finer grain and thus better enlargements.