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Thread: HOW DO YOU FOCUS WITH YOUR ALPA

  1. #101
    Subscriber & Workshop Member GrahamWelland's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Quote Originally Posted by darr View Post
    Dave,
    Be careful of this one too! When I got my Max I learned quickly after my first shoot employing 'Helicon Focus' that it is a different set of latitudes with MF digital. Read up on how others have devised their helicon technique before you use it on the MFD gear.

    Kind regards,
    Darr
    Darr,

    Do you have any pointers for this? I also use Helicon with the Alpa and in my experience it takes a lot more shots to get the equivalent DoF that I get from my 35mm full frame gear. I now over compensate with close up foregrounds after shooting lots of scenes with disappointing close up critical focus. This isn't an Alpa only issue btw - same thing for me with my Phase One DSLR with pretty much anything other than a 28 or 35mm.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  2. #102
    Senior Member darr's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Quote Originally Posted by GrahamWelland View Post
    Darr,

    Do you have any pointers for this? I also use Helicon with the Alpa and in my experience it takes a lot more shots to get the equivalent DoF that I get from my 35mm full frame gear. I now over compensate with close up foregrounds after shooting lots of scenes with disappointing close up critical focus. This isn't an Alpa only issue btw - same thing for me with my Phase One DSLR with pretty much anything other than a 28 or 35mm.
    Hey Graham,
    Ted from Optechs Digital explains it very well here:
    http://www.optechsdigital.com/Alpa_and_Hyperfocal.html

    And absolutely yes on "this isn't an Alpa only issue!"
    I tested my lenses based on what Ted did in this article and found very similar results.


    Kind regards,
    Darr


    I purchased my Max + Accessories from Paul last year, and Paul is my MFD Guru when I need tech support!
    Last edited by darr; 27th February 2011 at 12:32. Reason: format
    "Creativity takes courage." ~ Henri Matisse
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  3. #103
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    doesn't seem like you two are talking about the same thing...
    hyperfocal length and Helicon Focus

  4. #104
    Senior Member darr's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Quote Originally Posted by jlm View Post
    doesn't seem like you two are talking about the same thing...
    hyperfocal length and Helicon Focus
    Whoops, your right!!
    I do not use "Helicon Focus," the program. Sorry for the quick mistake in replying. But, that is a great article on hyper-focaling with MFD.

    Kind regards,
    Darr
    "Creativity takes courage." ~ Henri Matisse
    Darlene Almeda, photoscapes.com

  5. #105
    Subscriber & Workshop Member GrahamWelland's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Darr,

    I also use hyper focal focusing too. However, that too has it's challenge as the lenses teat longer such as with my 150mm. You are right about Ted's write up for this being very clear. I find myself stopping down as much as 2-2.5 stops from typical hyper focal focus settings which for me typically using f/5.6 settings even when shooting at f/11. (which leads then on to shooting several focus point shots at then using helicon focus to stack the images).
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  6. #106
    Senior Member etrump's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Quote Originally Posted by GrahamWelland View Post
    Do you have any pointers for this? I also use Helicon with the Alpa and in my experience it takes a lot more shots to get the equivalent DoF that I get from my 35mm full frame gear. I now over compensate with close up foregrounds after shooting lots of scenes with disappointing close up critical focus. This isn't an Alpa only issue btw - same thing for me with my Phase One DSLR with pretty much anything other than a 28 or 35mm.
    I had the same difficulty you are describing and it is extremely frustrating.

    A few suggestions based on my experiences:

    First be sure your lens is calibrated to infinity with your body and back. Two of my four lens were off and it made a huge (read HUGE) difference. The tolerances are extremely small and my lens that was calibrated past infinity was a stinker. Once calibrated they are scary sharp.

    Test your equipment so you know the exact distance where critical focus is at for each lens at all usable apertures and focus settings.

    What I did was focus the lens to infinity and take a tethered exposure at each aperture. The subject should be something that is easy to measure the distance from the camera to the closest spot with critical focus. Since I print my images large I want them to appear sharp at 100%, if you print smaller such as 16x20 "apparent" focus can be determined at 25%-50% display.

    I do the same at each aperture setting on the helical focus ring out to two stops shy of the aperture. For example, at f/16 I will test and record the nearest focus at f/5.6 and f/8. You will notice that the sharpest image will be at infinity with the overall sharpness degrading the farther you focus from infinity until it is obviously front focused (more than two stops shy of the aperture in my estimation).

    I created a chart for each lens with the apertures, focus settings and closest distance it was in focus. For example: on my 35xl, f/11 focused to f/5.6 everything from 4' or so to infinity is in focus.

    While shooting I use the sharpest setting that will keep my image in focus. If the subject to infinity can be kept in focus with the lens focused on infinity at f/8 I'm using the sharpest setting available. If the foreground is too close I'll either stop down or dial in some front focus as long as I am within two stops of the aperture.

    In this way, I know my subject is in focus and I'm using my equipment in the most efficient way possible. In my tests with the p65 and 72L I can stop down to f/16 at infinity with almost no loss of sharpness that can't be easily corrected in post. At f/22 and f/32 I can get acceptable sharpness at infinity but any front focusing closer than infinity and all bets are off.

    I initially used a laser distance finder and small tape measure in the field. After a bit of practice I didn't need the laser finder. I rarely blow an image due to focus problems where as before I routinely had issues. The longer the lens the bigger the problem.

    BTW: I use the same procedure with my P1 645df and it's glass.

    The new IQ backs have a live view sharpness scale and focus mask for which I am anxiously waiting.

    Hope that can be of some value to you.

    Ed

  7. #107
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Ed,

    Would you please clarify if following is correct understanding to what you describe.

    1. You have tested and determined that for your specific sensor and print size, the distance markings at the helical focus display sharp focus for any setting up to two stops (wider) of the aperture you actually use.

    2. When you can you focus at infinity.

    3. Alternatively you use hyper focal focusing or a setting between that and 2.

    Thanks!

    Regards
    Anders

  8. #108
    Subscriber & Workshop Member GrahamWelland's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Quote Originally Posted by etrump View Post
    I had the same difficulty you are describing and it is extremely frustrating.

    A few suggestions based on my experiences:

    ....

    The new IQ backs have a live view sharpness scale and focus mask for which I am anxiously waiting.

    Hope that can be of some value to you.

    Ed
    Ed,

    THANK YOU! I've been putting off going through this procedure but you're comments definitely resonate with me. I know for a fact that not all of my lenses perform the same and this level of critical testing is overdue for me to get best results. The fact is that I've erred on the side of slight laziness by relying on focus stacking which is fine for single images but not ideal at all when it comes to multi-shot stitches.

    Very helpful and much appreciated.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  9. #109
    Senior Member johnnygoesdigital's Avatar
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    Re: HOW DO YOU FOCUS WITH YOUR ALPA

    Most are aware of the amazing landscapes that are produced using tech cameras such as the Alpa 12 TC, Cambo Wide, etc. Can anyone share any portraits photographed with these cameras? Lenses like a 120mm APO Digitar N 5.6, seem perfect for this.

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