Help: Issue with SB900?

AndyBorzi

AndyBorzi

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Hi folks. Hope all had good chrimbo.

Well I got my D700, Siggy 24-70 & SB900 flash. :)

I was playing about today with the flash on camera to get used to the settings and noticed that nearly all of the photos with the flash were out of focus. Without flash anything taken is fine.

Examples: Not too scientific but both on tripod, both at F4 and the focus points the same. The flash in i-TTL mode (also tried on the A mode) Excuse the lack of white balance control but I wasn't too interested in that.

The focus was on the nearest candle holder.

1st With Flash

3145218752_d8d7745061.jpg

large

2nd Without Flash

3145218898_30e75ea4fb.jpg

large

The holders are about 4-5 inches apart and as you can see the flash has focused 4-5 inches behind the focus point. :shrug:

Anyone else had this? Anyone give me a clue if I am doing something wrong either in camera or in flash?

Cheers

AB
 
In low light the SB-900 will be using IR to help focusing (AF assist), it might be throwing it somehow.

Make sure you are not in AF-C mode, that disables focus assist.

Only use the central AF point, don't allow the camera to try anything "dynamic"
 
puddleduck said:
In low light the SB-900 will be using IR to help focusing (AF assist), it might be throwing it somehow.

Make sure you are not in AF-C mode, that disables focus assist.

Only use the central AF point, don't allow the camera to try anything "dynamic"
Click to expand...

AF-c mode - consults the encyclopedic D700 manual :bonk: .. Nope, I am using the AF-s mode.

I have been using central AF, though I have tried the "dynamic" way and it struggles abit in low light and pretty much produces the same results
 
I don't think you've got a problem, I think your AF point was on the right hand side of candle holder - its a cross point, and it simply liked the look of the firework box a bit more, its possible that the flash just increased contrast which made it more enticing as an AF target.
 
puddleduck said:
I don't think you've got a problem, I think your AF point was on the right hand side of candle holder - its a cross point, and it simply liked the look of the firework box a bit more, its possible that the flash just increased contrast which made it more enticing as an AF target.
Click to expand...

Possibly but it has happened on pretty much all of the photos taken with the SB900 today.

I have just found this: http://photo.net/nikon-camera-forum/00RgdD where apparantly this is a known issue by Sigma and they plan to release a software patch to correct it. Not sure how a patch from Sigma would be applied to Nikon camera/flash? Would they submit it to Nikon or something?
 
AndyBorzi said:
Possibly but it has happened on pretty much all of the photos taken with the SB900 today.

I have just found this: http://photo.net/nikon-camera-forum/00RgdD where apparantly this is a known issue by Sigma and they plan to release a software patch to correct it. Not sure how a patch from Sigma would be applied to Nikon camera/flash? Would they submit it to Nikon or something?
Click to expand...

Hmm.. that seems pretty conclusive.

A patch in Sigma parlance will be a re-chip.

In that case, I just get a refund tbh, and wait for it to be sorted out. Could take a while...
 
puddleduck said:
Hmm.. that seems pretty conclusive.

A patch in Sigma parlance will be a re-chip.

In that case, I just get a refund tbh, and wait for it to be sorted out. Could take a while...
Click to expand...

grr...I guess then if I register my problem with Sigma, they will send me a new lens when fixed? :thinking: (not!)

Just tried turning off the SB900 focus assist and just using the cameras and it works fine focussing on the nearest candle holder.

To be honest, I don't do a lot of shooting in near dark/very dark rooms so focus assist is not that much of an issue for me.

Getting a refund and waiting is not really an option because it is the only lens I have for the D700 atm. I cannot afford the Nikon equivalent. Are there alternatives in this focal range (24-70 f2.8) which is as good?
 
I had a feeling it was to do with AF assist even before your link, as its the only way flash can possibly impact AF.

If you need 24-70 you are stuck with the Sigma. If you can live with 28-75 then the Tamron 28-75 f/2.8 Di is a stonker. I have one on my D700 and its excellent, sharp, super fast AF and no compatbility issues.
 
I could live with 28-75 but it seems the Nikon mount version is only available in a couple of places! Jessops only stock the Canon mount version. (the 24-70 is from Jessops) and to be honest I don't trust ebay or the other e-tailers that stock these at the moment so I think it would be more hassle to exchange it right now.
 
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