Can''t get Zeiss CP2s to look sharp

I

ikander

Well-known member
My work recently purchased an entire set of Zeiss CP.2 PL primes for our Sony F3. Now I realize that these Zeiss lenses aren't true Cinema glass, but I can't for the life of me get a completely sharp picture with them. I get close, but there's something a little "off." I'm not shooting wide open (shot this at f 5.6). Is this just the results I should be expecting from these lenses? Are they innately just a little soft? Am I possibly doing something wrong (i.e. the PL adapter isn't on exactly right).

Screengrab of an interview attached. Notice how his eyes aren't totally in focus. Shot at 0DB with the Abel Cine Normal picture profile to internal SxS.

interview sample.jpg
 
That image totally sucks. If that is what it looks like on your monitor, you have a big problem.
It looks like the focus is pass behind the head. How are you focusing? Are using a tape measure or by sight?
I don't own CP2s but I have seen some demos and they looked good to me.
 
Douglas Villalba said:
That image totally sucks. If that is what it looks like on your monitor, you have a big problem.
It looks like the focus is pass behind the head. How are you focusing? Are using a tape measure or by sight?
I don't own CP2s but I have seen some demos and they looked good to me.
Click to expand...

Well, it's a recompressed jpeg on dvxuser, so no, that' snot exactly how it looks on my studio monitor.
 
Hi!
Take your lens to a technician and check it on a collimator. Do you change between eos mount and pl mount? Or maybe someone did this before you if you bought them used?

Roger
 
From the looks of the image I would think it is a back focus concern; I think you need to adjust the flange back. It would be best to have a professional optical house adjust the flange back for you. However if you are feeling up to the challenge? you can adjust it on your own with a small hex wrench , I cannot recall what size; It is a recessed hole slightly off center from the PL mount

hope this helps
 
Thanks for the info.

Where would I find a professional optical house in the DC area? Any instructions on the internet on how to adjust the back focus on the F3?

The F3 was bought new, but a coworker did remove the PL mount at one point to attach to attach an MTF adapter for using some nikon SLR glass.
 
I’m using Zeiss ZF.2 Cine Mod lenses from Duclos Lenses. Same glass as your CP.2 but only 9 iris blades on the ZF.2 lenses vs. I believe 14 blades on your CP.2 lenses and the ergonomics on your lenses are made the same on each lens for easier and quicker lenses changes.
I shot this interview using the F3 and AJA KPM. This frame is a JPEG file made from my Avid timeline. The interview was shot on the shoulder with a Zeiss 50mm macro planar 2 at F4-4.5. Shutter angle on the F3 was 180 and I was using PP 1. The interviews were all shot outside on the shoulder with no additional lighting or grip equipment. I was using “seat of my pants” focusing (nobody stands still) during an interview. My DP4 EVF was set to peaking which worked great.
Zeiss makes some great glass and CP.2 lenses are reasonably priced relative to what is on the market, but if I had the coin I’d buy some Cooke lenses in a heartbeat.
Those CP.2 lenses have interchangeable backs that use shims to adjust back focus. It could be set up wrong. I’d have them checked out by a professional.Lauren.jpg
 
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Try taking off the f-3 PL mount and remounting it. I had a similar problem and it was fixed by do that.
 
The Zeiss lenses are extremely, extremely sharp, especially at f/5.6. Look up the MTF specifications; they're way sharper than anything an HD camera could resolve. I would certainly not be inclined to think the lenses were at fault, and would instead look for some other reason (a cheap filter in front of the lens? An uncollimated mount?)
 
Barry_Green said:
The Zeiss lenses are extremely, extremely sharp, especially at f/5.6. Look up the MTF specifications; they're way sharper than anything an HD camera could resolve. I would certainly not be inclined to think the lenses were at fault, and would instead look for some other reason (a cheap filter in front of the lens? An uncollimated mount?)
Click to expand...

Thanks for the info, Barry. I'm thinking of sending the camera back in and get everything re-calibrated. I don't think it's the fault of the lenses. There's something wrong on my end.
 
I would say flange distance is off, or F3 mount not tight. Either way, if it was sharp on your monitor on camera it should have been sharp on big screen. I've never had an issue, even pulling focus open at T1.8 if it looked sharp on the LCD it looked sharp in post. even if it was flange that would only mean you could be out of focus if you didn't check it and were only doing it to mesured distances. A soft shot should always show up on LCD no matter if the flange is off or not, flange doesnt mean everything is out of foucs no matter what... It means the distances will be off on the markings, but thats all, you'd still be able to get a sharp shot, just not the correct marking for it.
 
I had the exact issue with my MTF adapter for Nikon. If you want to send away for adjustment then don't stress out and don't be afraid to adjust the flange depth, I had to do it myself and it worked out good. Go carefully and you will be fine. Get a back focus chart and a set of small allen/hex keys (F3 manual will give you the right bolt to adjust). Use your widest lens wide open. Using a good monitor adjust the allen bolt in one direction nice and slow if the image gets softer then reverse the adjustment until it becomes sharper. Continue the adjustment till it starts to soften and then reverse again until you find the sharpest point. Check with the other lenses and check the distance markings on the lens are accurate. If you have problems with either of these then I'd seek pro help.
 
even if the mount had bad collimation you should still be able to get manual focus and a sharp image, just your focus marks will be off
 
Are all the CP.2 lenses acting the same way? Test the others out at least you will then know if is the lens. Also if it is a lens issue don’t pay to get them fixed take them back and get a new one.
 
Thanks for all the help. I checked a few more of the Zeiss lenses and I can't acheive true focus with any of them. So, there's something up with the camera. If I'm reading everyone's advice properly, even if the flange distance is off, I should still be able to achieve proper focus, it just wouldn't match up to the correct mark on the lens.

Well, since I can never get truly sharp, I think the problem rests with the PL Mount and it not being properly in place. I may fool with that before I send the camera back.
 
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