Using Autofocus on digital medium format for the first time!

[Old School]

Hello everyone!
I just discovered this forum and had a little trouble figuring out how to join so bear with me, (I couldn't find the register button...) I'm slowly trying to adapt to digital technologies, something I should have done a long time ago, I'll admit! I thought I'd join and say hello!

I had a good career as a Fashion Photographer in the 90s but stopped working when I met my ex-husband (it's complicated...) now I would like to start shooting again, not for clients but mainly for myself and perhaps with the intention of making an art book some day.

I'm currently in the process of scanning all my film negatives and recently invested in some digital gear. My boyfriend came into quite a lot of money lately and bought me a Nikon D800 to replace my FM2 (I feel old!) as well as a Hasselblad H3D and I have been shooting again over the course of the last few weeks however I have come to the sad realization that my eyesight isn't as good as it once was and manual focusing is much harder on digital because the viewfinder is strange.

Could someone give me some advice on using auto focus in fashion photography when you have a constantly moving model? How can you focus on the eyes and then change your composition? I read on the internet that some people use the center focus point and then "lock focus" how ever this this done and then recompose. On the other hand some people seemed to say this was the worst thing to do... So now I'm very confused... What settings for focus should I use on my camera? I'm a bit confused as I have never used autofocus before, I knew it existed but never felt the need to try it until now, sorry if my question sounds a bit strange to some of you youngsters! Thanks for the help!

 

[ianjenn]

I am not sure how well the H3 focus works? But if you are shooting like fashion shows and have no control over the model I think the D800 would be best best maybe?

 

[Shashin]

I use the center point and lock focus and compose. It works well. Hasselblad, and someone else can chime in here, has something caller "True Focus" which will follow the subject.

And welcome.

 

[Dustbak]

Well, I feel like a youngster still but this question is not strange to me at all

Yes, TF (True Focus) works very well. Unfortunately it is not available on the H3. You need a H4 or H5 for True Focus.

When you use focus and recompose without TF you need to use a smaller aperture to make up for the focus shift when recomposing.

I found TF to work really really well. My rate of images where the focus was where I really wanted it went up significantly.

 

[fotografz]

Only the center AF spot works on your H3D. True Focus on the H4D and H5D doesn't track a moving subject anyway. It works best with a non-moving subject where you achieve focus which locks on anywhere you put the center AF spot and stays locked on, then when you recompose, the camera does the math to adjust for the changing plane of focus. Moot point since you don't have True Focus on your H3D camera anyway.

For the H3D, I suggest reading the manual and learn how to assign the AF function to the rear user defined thumb button so you can perform AF, then recompose, and shoot with the shutter button. It works a bit faster that way. To compensate for the shift in the plane of focus when recomposing, you'll have to stop down a bit. More with the H3D than the D800 because Medium Format has a narrower depth-of-field than 35mm.

On the D800 you could experiment with using Continuous AF mode ... which tracks the subject ... how well that would work in the specific fashion type circumstance you mentioned will have to be answered by a Nikon shooter.

Most of the time when I am using either 35mm or Medium Format Digital for more vigorous action oriented shots, I manually pre-focus on a specific area, stop down enough to maintain some depth-of-field, and have the subject try to work with-in that area of focus. Otherwise, I just focus/recompose as fast as I can ... and shoot a lot.

- Marc

 

[Old School]

I don't shoot fashion show but I shoot fashion as in a model or more who will constantly change poses ever so slightly.

So if I understand the recommendations:

- Use Continuous single point focus and use a special button to focus and turn off shutter focusing?
- Then recompose but be careful with aperture values.

Correct?

Which aperture values would you say are the 'sweet spot'? I suppose this is different depending on the focal length and whether it's the D800 or the H3D. Which values should I avoid and what can I do if I absolutely need a certain DoF? I suppose Defocus Control will also affect autofocus accuracy?

Here's a list of my lenses (I do think I am mainly going to use the D800 though, the H3D is extremely heavy, besides I have more Nikon lenses anyway!):

- H3D: 80mm f2.8

- D800: 50mm f1.4, 85mm f1.4, 105mm f2, 135mm f2 DC (With Defocus Control!), 200mm f4

 

[Old School]

Anyone?

 

[Shashin]

The focal length is more to do with preference of apparent perspective. I like normal focal length lenses. Some will prefer longer. Some whacky folks like short. It really depends on what you want. All of your lenses can make nice portraits, but all will be different.

The same can be said for the aperture. How fast do you want focus to fall off? The advantage of small apertures is you don't have to be careful about the subject slightly changing position. Some will say not to stop down too far--I am very happy shooting a D800 and Pentax 645D at f/16. Others will feel that f/11 is the limit. There again, it depends on the look of the image.

There are no right or wrong answers here.

 

[shlomi]

Your equipment isn't the best for accurate fast focusing.

In Hasselblad, you should be using the 50-110mm zoom for moving models - it is a much better auto focuser.
As far as the body, H4D has much better auto focus capabilities than H3D.
You shouldn't do so much manual work you were talking about, the right camera + lens will focus correctly and easily.

As far as Nikon, I don't know their lenses very well, but from Canon I know the premium zoom lenses auto focus much better than the primes, so I would look at 24-70 AF-S on the D800.

 

[pedro39photo]

In my H3DII i made in the settings the AE-L button to AF.

I don´t use the half press shutter button to Exposure neither to AF.

For me its better to focus the target with that button, recompose a take pic.