Focus issue help please (with screen shots)

[Kendo556]

hey everyone
so here is my issue i was shooting a cam test the other day on an ARRI S 16MM camera i used two different lenses a 12 mm-120 mm zoom lens, and a 5.9mm fixed focus lens. my issue is that on wide shots with both lenses i'm getting soft focus i'm measure for focus as well.

now i'm thinking its either my lenses are not calibrated or i measured my focus wrong. but then i started thinking that the 5.9 mm wide angle lens is a fixed focus and from my knowledge shouldnt that be in focus? so then i was wondering if my camera has a depth of focus problem

12mm-120mm lens F2.8 24fps

Here is the first shot notice the letters on the slate are soft as well as the whole frame itself

12mm-120mm lens F2.8 24fps

same thing soft focus on the overall image

these next two shots are shot on using the 5.9mm wide angle lens with fixed focus

5.9mm wide angle lens fixed focus F2.0

this image is more noticable then the shots of the slate on this picture is what makes me think i have a depth of focus issue because the lens was fix focused

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5.9mm wide angle fixed focus lens F2.8

this is the same shot and the other wide just after telecine

12mm-120mm lens F2.8 after Telecine

12mm-120mm lens F2.8 after Telecine

so hope this information is enough if not let me know what else you need thanks a bunch

to help these next shot are shots that were in focus i meassured these as well

 

[Kendo556]

anyone??

 

[Kendo556]

no info at all?

 

[Noel Evans]

There seems to be an issue as you well know, but its probably going to be hard to pinpoint without looking at your set up.

I can see you noted the focal length of the lenses but what lenses were they?

I also not many of these shots are done with a very open aperture. How do these compare when you are arounf f4-f6?

 

[Kendo556]

Very true with out seeing my camera package i understand we could figure out the exact problem i mainly just wanted to see if others had any other suggestion of what it could be.
and by the way THANK YOU very much for takin a look at this thread im shooting the short film in 3 weeks i have already shot another camera test but have not seen the results yet .

the lenses are:
ANGENIEUX-ZOOM TYPE 10 X 12 B 12MM-120MM

the wide angle lens was a

CENTURY PRIME 5.9MM

yes there are shot mainly from a f4.0 down to a f1.4 the reason im shooting so open is because im in a house in a sound stage and the house has a roof as you can see. also i am shooting on FUJI ETERNA VIVID 160 ISO so on that note i cant use any lights lower then a 1k and i cant have anything above a 2k in the house unless i use some HMI's

thanks again hope this info is helpful

 

[Noel Evans]

Im going to guess simply your backfocus is out... check this - Taken from Mclarenblog.com

Image is out of focus.

Did you set the diopter first? Setting the diopter is the first step you should complete before thinking about using any lens. Just take the camera with or without a taking lens and shoot something blank like a white wall, the north sky if outside, or the sidewalk. Concentrate on a ground glass image in the viewfinder. Make darn sure that that ground glass is as sharp as you can make it for your eye by rotating the diopter ring close to the eye cup. Most Arri S cameras come with a target on the ground glass which makes finding ground glass focus pretty easy. It is possible to come across a camera without a target scribed into the ground glass surface. Just concentrate on the ground glass grain until it looks as sharp as you can get it. Whenever any camera person uses the camera, that person and only that person must reset the diopter. Never set the diopter for another camera person!
Now that the diopter is properly set, do not change it but lock it in place using the viewfinder lock ring.
Take the lens you intend to use and set it to infinity focus. The infinity marking on a lens is a figure “8″ laid on its side. Infinity is a fantastic way to calibrate a lens or check its calibration.
Take the iris ring found on the lens and open it ALL the way. Do not stop it down one little bit. It must we wide open to remove any depth of field. [Dept of field is the area between a near and far point from the lens that shows acceptable focus.]
Through the viewfinder, look at an object with fine thin lines at infinity. Now lets get real here. Just pick an object at least a quarter a mile away. Power poles, power lines, high rise buildings with windows, edge of a tall building, tall trees, etc are really good objects to pick. Now we are going to concentrate on the fine lines of one of the far distant objects. Rotate the lens focus ring and rock the ring back and forth until you get the best focus.
Is the image sharp? Take into consideration that the image is composed on to a ground glass and the image by definition can not achieve any fantastic detail with this method but it should look sharp.
Look at the setting of the lens focus ring. Is it right on the infinity mark? If it is not, either you did the diopter adjustment wrong or the lens is out of calibration.
Image seems out of focus (more rigorous check).

Obtain a Siemens star target and place it at a convenient distance from the lens. This will require that you also have a tape measure. Look at the lens and look at the lens markings for distance. Choose a distance from the camera corresponding to a mark found on the lens. For example a lens mark might show 10 feet. If a lens is set to be in best focus at 10 feet but is not when we look though the viewfinder, then there is an error. If we choose 10 feet for the Siemens star then place that star image 10 feet from the camera. Most cameras have a film plane marking to indicate distance measurements. On the Arri S is on the opposite side of the operator close to the matt box attachment. The mark looks like a circle with a line running through it. One of the tape measure should be placed at that mark. Place the target Siemens star at a precise distance from the camera which is the
SAME as the distance you set on the lens.
Perform the viewfinder ground glass focus as described above. Make darn sure this is as precise as you can get. If you get the ground glass calibration wrong this whole method falls apart.
Now open the lens all the way. We want minimal depth of field.
Rotate the focus lens ring back and forth to make the Siemens star appear as sharp focus as you can get. If you had chosen 10 feet, you will be rocking the focus ring closer than 10 feet and further than 10 feet to find the best, sharpest Siemens Star Chart image. Please remember that ground glass focus method is not going to be immaculate because the ground glass will soften any image. Just concentrate on the lines you see in the lens of the Star Chart and stop when the target gets sharp. The beauty of the Siemens Star Chart is that the center of the target goes out of focus in a hurry with any small deviation from perfect focus.
Now with the lens left where you found the best focus, compare the lens focus ring reading to the measured tape distance of the Siemens star to camera film plane distance. The two distances should be within four inches of each other. It they are not then a problem exists with the camera or the lens. Do not use the camera but return it to checkout or rental house and tell them that the tape vs eye measurements do not coincide.
Tip: Perform this procedure a few times and to see that you get the same results.

Obtain Siemens Star Chart A sample of this chart in a pdf document can be found here: http://www.jvcpro.co.uk/getResource2/e2siemenschart1.pdf?id=6145
Scroll down to the second page which shows a really good Star Chart and print that page out. It is a good idea to take the printed Star Chart and glue it to a flat surface that you can carry around with you.

NOTE: Lens back focus is different with each model camera. Lens back focus is the distance behind the lens where the real sharp focus occurs. This sharp focus must occur on the film emulsion as it sits in the film camera aperture. Occasionally we send in our zoom lenses for collimating. We provide a camera with the lens. Some zoom lenses are matched for a particular camera. In addition, an exact lens opening on the turret is optimum and sometime comes with a special marking. For most student projects you should not care which zoom lens goes with which camera. In the professional field you will take great care that the lens properly matches the correct camera. In any case, do not use lenses intended for another camera as the back focus might and probably will be wrong.

 

[Kendo556]

AMAZING thanks i did set my diopter yes but i did not do that test i will try that test and see what i get. what i did do in my last camera test was measure for focus and trust it was correct. then focus with my eye and trust only that, but also measured my distance to my subject from my focal plane mark and marked down the measurment shown on my lens and when i get the filmed processed this week i will compare my results and determine whats going on. thank you tons for giving me some more knowledge!!