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06-28-2011, 12:43 PM   #16
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Very impressive!

06-28-2011, 08:46 PM   #17
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Great report, and great photos as well. Thanks for posting this!
06-29-2011, 02:30 AM   #18
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Great report with impressive photos.


Any ideas when this lens should become available?
06-30-2011, 01:39 PM   #19
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QuoteOriginally posted by tcom Quote
Any ideas when this lens should become available?
B&H says July on the website, so it should be available soon.

06-30-2011, 03:10 PM   #20
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Harklee,

You have mentioned focus stacking in the past - do you mind sharing your workflow when you incorporate focus stacking?

I'm just getting started in working with it, and appreciate any insight.

Thanks!

Laurence
07-10-2011, 10:49 AM   #21
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QuoteOriginally posted by lnorton Quote
You have mentioned focus stacking in the past - do you mind sharing your workflow when you incorporate focus stacking?
Laurence,

Here is a rough write-up of the process,

First, run a series of tests on the lens you would like to use.

Tape a small patch of tick marks on your lens (as shown in the pic) so that you will be able to remember and go back to a specific focus setting for your lens.



Choose a place with noticeable textures or objects in the foreground so that you can identify if any spot is in or out of focus. Set up a few targets (or just pick some objects in the foreground), measure and remember their distances from the camera using a long tape measure or laser distance meter.

An example of laser distance meter :
http://www.google.com/products/catalog?q=leica+distance+meter&hl=en&rls=com....d=0CJ8BEPMCMAA#

Now take a number of shots with different focus settings (at different tick marks) and analyze them to figure out the DOF of each shot (each setting). Since DOF is something somewhat subjective to the photographer himself and viewers, you have to establish your own standards.

In the field, carry a laser distance meter or try ballparking the distance to your nearest foreground and also estimate the distance to the farest background, which will give you the necessary DOF for that specific shot. Based on your knowledge, take multiple shots that will cover the required DOF.

Load the images into one Photoshop file, choose the one with background (or most coverage) as your background layer. Now you have multiple layers in your file, select (ctrl+click in the layer window) them all (or one pair of a foreground layer and the background layer at a time), go to 'Edit' -> 'Auto Align Layers' -> 'Auto'. This will resize your foreground layer(s) to fit the background layer (if the auto align doesn't work, you can also manually align it).

Now you can use a conventional layer mask to seletively (manual) blend, or go to 'Edit' -> 'Auto Blend Layers' -> 'Auto' to automatically blend them. Please keep in mind that the foreground layers are always a tad smaller in size than the background layer, so make sure to crop the photo properly (in case you are using the auto blending, you may want to do this right before merging to avoid blurry edges).

Some folks seem to use specialized focus-stack softwares, but I don't have any experiences them. Hope this helps and let me know if you have any questions. Thanks!

- Hark

Last edited by harklee; 07-10-2011 at 10:59 AM.
07-10-2011, 10:35 PM   #22
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Hark,

Thanks so much for taking the time to provide such a detailed response. I appreciate you sharing your approach. I hadn't thought of a laser distance meter. I'll dive into your suggestions and see how it works for me.

Thanks again.

Laurence
07-14-2011, 12:22 PM   #23
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Hark,

Regarding Focus Stacking, do you have problems with ghosting or alignment? I shoot extremely detailed landscapes that feature prairies and millions of blades of grass and flowers.

Also, if you were to shoot using hyperfocal distance, couldn't you try something subtle like taking just 2 shots at, say, f8? Let's say that the nearest subject is 2 feet and we also want infinity.
- 1st Shot: At f/8 on the 25mm lens on the 645D, you would set the lens to the hyperfocal distance for f/8, which is almost exactly 8 feet. This shot would get everything sharp (for the most part) between 4 feet and infinity.
- 2nd Shot: At f/8, focus the lens at something like 3 feet (a foot beyond the nearest subject) and guarantee that everything between 2 feet and a good amount beyond 4 feet would be in focus.
(Of course, you could probably take the first shot and focus a little further out than 8 feet to better guarantee that infinity looks sharp. Possibly set focus to 10 feet.)

The reason I'm asking is because, in my situation, taking too many shots will not work because of the problem with the wind blowing around the grasses and flowers. Even small movements will not align and cause problems with the stacking.

Thanks for your thoughts!

Mike

07-17-2011, 07:42 PM   #24
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25mm on film?

Has anyone tested this lens on a 645N/NII film body, with particular attention to how well corrected the CA is when you take the digital artifacts of a wide angle out of the equation?
07-18-2011, 12:08 AM   #25
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Harklee,
Your images are stunning. I really love the Lake Tahoe Zephyr Cove shot. I've followed your posts for a few months now and thanks in part to your thoughtful reviews and beautiful images, I've taken the plunge and should get my 645D in a week or two. Thanks for your help.
Joe
07-18-2011, 04:25 AM   #26
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QuoteOriginally posted by Ivan J. Eberle Quote
Has anyone tested this lens on a 645N/NII film body, with particular attention to how well corrected the CA is when you take the digital artifacts of a wide angle out of the equation?
I have a few samples to be processed, and should show them here by the end of this month :
https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/148891-...5mm-f-4-a.html
07-18-2011, 12:08 PM   #27
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I shot this on an inexpensive camera just to demo Helicon's Focus stacking software that has a 30 day free trial. The shot has about 8 focus points, IIRC.




07-18-2011, 01:46 PM   #28
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Excellent !
07-18-2011, 01:49 PM   #29
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I should note that this is the output straight from the software without using its ability to hand fix imperfections resulting from the merge as you can see on some of the lens edges.
07-19-2011, 09:52 AM   #30
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QuoteOriginally posted by tuco Quote
I shot this on an inexpensive camera just to demo Helicon's Focus stacking software that has a 30 day free trial. The shot has about 8 focus points, IIRC.



Tuco: Thanks for the info regarding Helicon Focus. I just down loaded the trial, and will give it a try for landscape/seascape work. If I get any "keepers", I will post.
Dave
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