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Tilt on the Alpa Max

alvinjamur

New member
I'm thrown off by something very basic here (perhaps the lack of
sleep!).

My Imaging train on the front end looks like this (read down)

SK 120mm lens
Alpa T Adapter
Extension 006
Extension 011
+
ALPA Max
+
Hasselblad Adapter (Shimmed correctly)
+
Phase One IQ250

I did a simple test.
Kept a book about 8 paces away from camera.
Kept another book on a table about 24 paces away.
Goal is to get book at 8 paces and 24 paces sharp.

At f11 and f8, focused on near book at 8 paces away (1/3 of dist).
Then started to tilt down so the book at 24 paces would also focus.
No Go.

Momentarily confused. What am I doing wrong?

- aLV
 
I believe you should focus back a little bit to get the tilted focal plane on both books. Thanks to the LiveView on the IQ250 it is easy.
 

alvinjamur

New member
Did u mean defocus from the first book until the 2nd book
comes into focus??

Brain fried. Will try tmoro.

TY!

- aLV
 

dchew

Well-known member
Depending on the height of the books, you will probably want to focus much farther away than the front book. Maybe even beyond the second book. Once you begin tilting, infinity focus puts the focus plane horizontal. The amount of tilt brings that horizontal plane of focus closer to the camera (raises it up). So if the two books are at the same height, you would want to focus at infinity, then tilt until both books are in focus. As you bring in the focus from infinity, you are essentially tilting the plane of focus. If the second book is only a few feet higher than the first, your focus should be very close to infinity.

8 paces will be about 6m, 24 about 18m. Your table is probably 1m high. Assuming the first book is on the ground, that's a 1/12 pitch; pretty low angle. I bet your focus distance should be much closer to infinity.

Dave
 

alvinjamur

New member
Yup!

I had forgotten to put one of the required Alpa adapters.

I'm going to just color mark things and that way it'll be
idiot proof! LOL.

For the 90mm and 120mm SK, I needed to use the Tilt and
a 6mm and 11mm adapter (34mm total length).

For the Rodie 40mm and 70mm, I needed to use the fixed
34mm adapter.

Everything works beautiful. Since this was the first time I played
with the Alpa tilt adapter, focusing on foreground and tilting for
background is a lot finer as a process. Just a question of muscle
memory building, I guess.

-aLV
 

dchew

Well-known member
Good to hear.

I think you mean the fixed 17mm adapters for the 40mm and 70mm. Those are 17sb's, not 34sb.

That is interesting that you find it easier to focus on the foreground then tilt for the background. Regardless of how you approach it, the one thing I find important is to come at the focus point knowing which side you are on. Almost like the old "offset technique" in orienteering. If you purposely go to one side or the other, then you know which way you have to turn to get to your destination. Nothing more frustrating than going back and forth not finding anything sharp!

Ciao,
Dave
 
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