Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: gfx on February 16, 2010, 06:32:27 pm

Title: Auto Focus efficiency
Post by: gfx on February 16, 2010, 06:32:27 pm
Hi,
I'm interested in the efficiency of the auto focus Hassel H3D/H4D vs. PhaseOne 645DF.
Regards.
Title: Auto Focus efficiency
Post by: michael on February 16, 2010, 06:37:05 pm
Don't look to any MF camera for great autofocus. They're equivalent to 1980's SLRs. Having said that, the new Phase One DF camera is better than the previous AF model, and in my opinion is now on a par with the Hassy H series.

Michael
Title: Auto Focus efficiency
Post by: JerryReed on February 16, 2010, 07:18:15 pm
Quote from: michael
Don't look to any MF camera for great autofocus. They're equivalent to 1980's SLRs. Having said that, the new Phase One DF camera is better than the previous AF model, and in my opinion is now on a par with the Hassy H series.

Michael

With the advent of ever larger CCDs and greater numbers of pixels the difficulty of achieving a critical focus seems harder than ever, without live view.  But, what practical solutions are there now to implement  a live view feature in the field?  What may likely be available to review on a screen the image that the sensor is seeing?  Your view into the future would be great to know.

Jerry
Title: Auto Focus efficiency
Post by: Barry Goyette on February 16, 2010, 08:22:57 pm
I have to say that when it comes to Hasselblad, the autofocus is extremely accurate.....100% of the time. It's not a predictive system like you will find on a 35mm system, but more accurate on a non-moving subject than any I've experienced. I also feel it is decently fast for a MF system. I don't ever feel like I'm waiting for it to do it's job except maybe on the 120 macro, which has an extremely long travel. (generally with MF subject matter it doesn't make sense to let the autofocus do all the work..coarse focus manually, and then let the AF do the fine tuning, it's more accurate than the viewfinder optical system).

Barry

Title: Auto Focus efficiency
Post by: Nick-T on February 16, 2010, 08:36:44 pm
Quote from: Barry Goyette
I have to say that when it comes to Hasselblad, the autofocus is extremely accurate.....100% of the time. It's not a predictive system like you will find on a 35mm system, but more accurate on a non-moving subject than any I've experienced. I also feel it is decently fast for a MF system. I don't ever feel like I'm waiting for it to do it's job except maybe on the 120 macro, which has an extremely long travel. (generally with MF subject matter it doesn't make sense to let the autofocus do all the work..coarse focus manually, and then let the AF do the fine tuning, it's more accurate than the viewfinder optical system).

Barry

Barry
This might be obvious but are you aware there's an option to restrict the range in which the 120 focusses? Under custom options somewhere..

Nick-T
Title: Auto Focus efficiency
Post by: David Grover / Capture One on February 17, 2010, 02:08:03 am
Quote from: michael
Don't look to any MF camera for great autofocus. They're equivalent to 1980's SLRs. Having said that, the new Phase One DF camera is better than the previous AF model, and in my opinion is now on a par with the Hassy H series.

Michael


I think that's a bit unfair Michael.

The H (I can't speak for the DF not having picked one up with the latest firmware etc) but is way faster than a lot of SLR's of the time you mention.

Pick up the 35-90 zoom and you will see what I mean.

Also there have been some interesting discussions of late on AF accuracy on 35mm and how it has been less than consistent.

The H system has been improved over the years AF-wise.  Better maths, faster processing...

On the H4D there is a new AF assist light which helps in low light conditions.

David

Title: Auto Focus efficiency
Post by: Frank Doorhof on February 17, 2010, 02:13:25 am
AF on MF is most of the time slower than on my Canon 5DMKII but much more accurate.
Where the 5DMKII sometimes misses the eye and focusses on the hair or nose the 645AFD/III is dead one.

I compared the AFD/III to the DF recently and must say that the DF is indeed faster but it was not that much of an impact that I will sell my 645AFD/III.
Although it does feel tempting