Jump to content
Sign in to follow this  
Blenny84

Beginner help! Sony RX100ii focusing issues

Recommended Posts

Hi guys,

 

So I bought my first compact kit from ebay and tried it all in the pool yesterday but something is not quite right and can't figure out what it is.

 

Setup:

Meikon RX100ii housing

Sony RX100ii - setup for underwater use only following this guide http://www.uwphotographyguide.com/sony-rx100-iii-underwater-settings

Camdive Fish eye wet dome lens

ISO Auto 160-800

AF off

 

Issue: The object (a weight) I was filming got out of focus as soon as I zoomed in a little or got a bit closer to it (1 feet +-) on video mode. Also the image was getting darker overall but more pronounced around the edge of the frame - no vignetting though, it was as if someone suddenly switched off the main light.

Bigger objects like other divers doing some training seemed to be in focus all the time.

 

As I zoom out it gets in focus and when zooming in again out of focus.

 

I only do video with the camera and the dial was setup on A mode. I just pressed the movie button to start filming and was fiddling with the zoom a bit to test.

There was a message on screen all the time that said 'Tracking focus' I have no idea if this is related or not.

There was a layer of water between the house port and the dome lens (as it is supposed to be?) so the lens was working fine at providing wide angle.

 

I changed the focus area from flexible spot to center but did not make any difference.

 

Does anyone know what this could be? I hope there is nothing wrong with the focusing on the camera...

 

Cheers

Edited by Blenny84

Share this post


Link to post
Share on other sites

Hi - I have used the RX 100 II for a few years and now upgraded to a Nikon D500. The sony is great. I only shot stills -- but just to clarify - when you say in your post "AF off" - does this mean autofocus off? Tracking focus allows the camera to move the focus point to follow objects and is turned off by pressing the center button of the wheel. Sorry I could not open your attachments. I presume you have already downloaded the electronic manual see https://docs.sony.com/release/DSCRX100M2_guide_EN.pdf.

 

Best of luck! John

Share this post


Link to post
Share on other sites

Thanks John,

 

I meant AF Iluminator off

 

I did some more testing at home in low light with limited ISO 160-800 first and the results were identical to underwater. As soon as I zoom in a bit the image gets really dark. I then changed the ISO to 32000, 1/50 f1.8 and it got much better and allowed me to zoom in much more before it got darker.
Does this mean it was purely due to the fact that there wasn't enough natural light in the pool?
Is this behavior expected from this camera?
Edited by Blenny84

Share this post


Link to post
Share on other sites

From an on-line review:

"35mm-equivalent focal lengths range from a 28mm-equivalent wide angle to a 100mm-equivalent telephoto. Across this range, the maximum aperture falls from a bright f/1.8 at wide angle to f/4.9 at telephoto. The latter is rather dim, albeit understandably so, given the lens and sensor sizes. Focusing is possible to as close as 1.9 inches at wide angle, or 21.6 inches at telephoto."

 

It is possible that you were at max aperture, and when you zoom that max decreases and the picture gets dark.

it is also possible that you were just too close for the telephoto to focus.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks Wolf Eel,

 

I also found the below regarding the relation between zooming and f-stops at dpreview.com

 

Be careful about zooming as you lose 3 stops from wide to tele with the RX100M2 (and RX100) - you may be better off shooting wide to take advantage of the lower ISO f/1.8 can give you and cropping. Also, the more you zoom in on your subject the higher the shutter speed you will need to avoid motion blur.

 

Understand the steep relation of f-stop and zoom on this camera and be wary of loosing light with zoom. Get close, or else this camera looses it's edge in performance over the other P&S cameras.

 

I guess if you also add low light conditions to that perhaps the whole thing makes a bit more sense.

 

I will give it another try in the pool without using the zoom and with a torch or some sort of light to see how it behaves.

It is also possible I was too close as it is easy to do that in the pool and not in open water on a reef.

 

Thanks

  • Like 1

Share this post


Link to post
Share on other sites
Sign in to follow this  

Sponsors

Advertisements



×
×
  • Create New...