Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: shaun on August 13, 2018, 04:30:36 pm

Title: sony a7r111 focus at night
Post by: shaun on August 13, 2018, 04:30:36 pm

I recently got sony a7r111 & 24-105mm lens. Great but couple of things. When shooting at night, floodlit buildings etc it really struggled to focus. Never had this before on canon 5d11or even my old Hasselblad. Tried moving focus point to edge of building where it should have locked on but no joy. Solution was to move point around till it eventually focussed then quickly switch lens to manual focus but really I didn't expect this.

On a similar note under studio flash is there a mode so view finder is nice and bright.

Also similar when shooting stars couldn't see a thing except lots of noise. Results were ok but couldn't see to compose. I'm pretty sure there must be can easy fix with last 2 points.
Title: Re: sony a7r111 focus at night
Post by: Martin Kristiansen on August 14, 2018, 03:29:43 am
A couple of things come to mind here. And I could be totally wrong so please this is just a suggestion.

You say there is a mode so the viewfinder is nice and bright when using studio flash. Do you mean turning off “Live View Display” and setting it to effect off in the menu? If this is what you mean you might be using the camera with this effect “on” when shooting at night. If you are it negatively impacts the cameras ability to focus, particularly in dark situations. What happens when using this effect on is the lens is stopped down to a stop or two above the aperture selected and that means less light to focus with hitting the chip and difficulty finding focus as focus falls off more slowly at smaller apertures making it more likely for the lens to hunt focus. Try setting “Live View Display” to effect off and see if that improves matters when focussing at night.

Next thing is your workaround to auto focus and then quickly turn the lens to manual focus and recompose. Would it not be better to select a spot focus and move the focus area to the edge of the frame where you can find focus. Or set auto focus to back button so you can focus on something wherever you want and then press the appropriate button. Lens will focus and hold focus at that distance once you stop pressing the button allowing you to recompose. Not ideal but better than what you are doing. Or simply manual focus with the manual focus assist set to on so as you start to focus the view will zoom in allowing you to focus accurately.

Noisy viewfinder when very dark is an issue. It can be improved by using the lens wide open again with the setting live view effect off. It is another area where fast lenses also improve things a fair amount even if not actually shooting wide open.

Apologies if I have misunderstood or misinterpreted what you are trying to do and are doing.
Title: Re: sony a7r111 focus at night
Post by: shaun on August 14, 2018, 04:51:39 am
Thanks Martin got that sorted  Live view> setting effect off.

Easy when you know how, set this up as a quick function now.

All the best
Title: Re: sony a7r111 focus at night
Post by: Martin Kristiansen on August 14, 2018, 05:02:47 am
No worries.

Thing is changing to mirrorless is such a smooth process on one level that little things like this trip you up. I was fed up with the focussing of my a6300 but really liked the live view effect on to adjust exposure. Then I read that it was weakening my AF ability. A bit of a learning curve.

Last week I photographed old maps and forgot to reset the APSC setting so all my files were 17MP. Really irritated myself.
Title: Re: sony a7r111 focus at night
Post by: shaun on August 14, 2018, 12:50:29 pm
yes and I was scratching my head on this one. Had it away for 5 weeks on a trip and just worked around it so glad its a quick fix.