D70 unable to focus

hleonz · 28th October 2004

Hi,
Need some advise.
I tried to take picture of my room's wall, but D70 is unable to focus. My room light is on and the wall is plain light blue (without anything on it).

What's wrong here?

Thanks,
Herry

espn · 28th October 2004

Yes, there must be something contrasty enough for it to AF. If the whole frame is the same color, the camera might not be able to focus.

BurgaFlippinMan · 28th October 2004

i've noticed, that when trying to focus on something like a plain wall in the dark with the af assist lamp, the d70 is not able to focus, but with the af assist coming from the sb800...it does the job well.

Kho King · 28th October 2004

autofocus system needs a texture in order to lock on to focus. Horizontal or vertical line.

kex · 28th October 2004

Minolta AF system can focus on a white wall though.

2100 · 28th October 2004

Originally Posted by kex

Minolta AF system can focus on a white wall though.

Wow....that means it can also focus at a blue sky? How does it do that?

Leongfm · 28th October 2004

Originally Posted by kex

Minolta AF system can focus on a white wall though.

I think that's because the Minolta AF system uses infra-red to focus while most D/SLR AF systems do not use IR. Most flashlight uses IR to focus though. This explains why your DSLR could not focus on the wall by itself but was able to do so when the flashlight was attached to it. (Autofocus change from the body to the flash).

Zerstorer · 28th October 2004

The AF of the older minolta SLRs is extremely accurate and precise in lowlight despite their rated specs, they zip to focus with very little hesitation or microhunting. This is partially due to the inbuilt near IR AF assist that is built into most of their bodies.

However, their advantage is even stronger if you compare AF with an external flash attached. The IR illuminator of even a 13yr old minolta flash has a better IR illuminator than the SB800. My Dynax 8000i + 5200i combination can lock focus on a blank wall in pitch black conditions faster than my F100 + SB800 can. The AF assist of the SB28 fares much worse in this regard.

28th October 2004	#1
hleonz New Member Join Date: Aug 2003 Location: Singapore Posts: 44	D70 unable to focus Hi, Need some advise. I tried to take picture of my room's wall, but D70 is unable to focus. My room light is on and the wall is plain light blue (without anything on it). What's wrong here? Thanks, Herry

28th October 2004	#4
Kho King Senior Member Join Date: Jan 2002 Posts: 2,799	autofocus system needs a texture in order to lock on to focus. Horizontal or vertical line. __________________ KOH KHO KING http://ShaShinKi.com ~ Malaysia Online Camera Shop! :cool:

28th October 2004	#2
espn Deregistered Join Date: Dec 2002 Location: Planet Nikon Posts: 22,045	Yes, there must be something contrasty enough for it to AF. If the whole frame is the same color, the camera might not be able to focus.

28th October 2004	#3
BurgaFlippinMan Member Join Date: Jun 2004 Location: KL Posts: 585	i've noticed, that when trying to focus on something like a plain wall in the dark with the af assist lamp, the d70 is not able to focus, but with the af assist coming from the sb800...it does the job well.

28th October 2004	#5
kex Senior Member Join Date: Oct 2002 Location: beebox Posts: 2,101	Minolta AF system can focus on a white wall though.

28th October 2004	#8
Zerstorer Senior Member Join Date: Jul 2002 Posts: 3,610	The AF of the older minolta SLRs is extremely accurate and precise in lowlight despite their rated specs, they zip to focus with very little hesitation or microhunting. This is partially due to the inbuilt near IR AF assist that is built into most of their bodies. However, their advantage is even stronger if you compare AF with an external flash attached. The IR illuminator of even a 13yr old minolta flash has a better IR illuminator than the SB800. My Dynax 8000i + 5200i combination can lock focus on a blank wall in pitch black conditions faster than my F100 + SB800 can. The AF assist of the SB28 fares much worse in this regard.