AC130: Focus/Zoom Issue

B

BradComLLC

Member
I’m not sure if this has been discussed before, but I’m new to the group and I just received my 130a last week. I have just been reading about it and looking over the documentation and testing with the camera while reading. While doing so, I noticed something odd about the zoom and focus.

I’ve worked in the industry for over two decades and never seen this before. As a reference, I have the display set to show numbers for the zoom and focus. I’m using the manual focus and servo for zoom. According to documentation, the zoom goes from Z00 - Z99 and the focus MF00 - MF99 with MF95 being infinity.

I first noticed an issue while working with the camera while I was reading at my desk. I zoomed all of the way in to a photo (about three feet away), set focus, and when I started to zoom out, the focus rolled out of focus and rolled back in as I continued to zoom out. Curious, I tested it noting the numbers. Here are the notes. Z00-MF 42, Z89-MF51, Z82-MF42. Anybody have an idea what is going on? The camera just changed its focus by itself. At first I thought it may be a backfocus issue, but don’t see an adjustment for it.

I also noticed that focus doesn’t always go down to MF00. So I did some more tests. I zoomed out all the way and set focus to MF00. I then started to zoom in and at Z66, the focus started to change on its own until the numbers were MF41 at Z99. It would not focus below MF41.

Does anyone know if this is normal? If so, why? Barry? Jan? Is this a Panasonic thing?
 
Hi Brad,
Firstly welcome to the team! You will get a detailed technical explanation of this I'm sure, but it has been discussed at length and in summary what I think you are seeing is the switch from normal focus to macro and vice versa. This series of cameras, with this massive zoom, all "lose" focus momentarily at that switch point and is just something to be aware of. I'm sure others will give you the technical machinations of what is happening , but it is just a design thing and they all do it.

And personally I wouldn't put too much weight on the numbers because light, aperture and ISO will affect DOF greatly and send them all over the place. Use the focus assist , it works well. The 130/160A are capable of stunning imagery - I struggled initially when switching from Sony to Panny, but understanding the nuances of these cameras is crucial, paricularly with regard to scene files. ( Barry's book is a necessity) Best of luck and enjoy!
Cheers!
Rod
 
Rod,

Thanks for the info. I was reading Barry's book while I was doing the test and you are right, it is full of information. I didn't see the macro switch issue though. I'll do some more testing and work with the camera.

Have a great day!
 
Yes, it's related to the minimum focus distance achievable at any particular zoom setting. If you set the zoom at Z00 and the MF at MF00, then as you zoom in you'll see exactly what happens to the minimum focus distance. The macro range is the range where the camera can achieve closer focus than it could when at full telephoto.
 
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