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Forum: Troubleshooting and Beginner Help 04-26-2013, 09:08 AM  
K5 Exposure Bracket Shift
Posted By Karl Stevens
Replies: 11
Views: 992
Sounds like you either have "Horizon Correction" enabled or are using composition adjustment. I found that when bracketing, they only apply to the first shot.
Forum: Digital Processing, Software, and Printing 01-13-2013, 07:39 PM  
Making HDR Images
Posted By Karl Stevens
Replies: 97
Views: 7,715
Civiletti,

Wikipedia says exposure fusion is not HDR. (exposure fusion cannot be considered an HDR technique)
The people who developed the algorithms for exposure fusion say it is not HDR.
The people who write HDR software say it is not HDR.
The people who write exposure fusion software you use say it is not HDR.

And yet somehow you believe they are all wrong. Every single one of them. That boggles the mind.

Note that they do not say "there may be other ways to do HDR", they say flat out "exposure fusion cannot be considered an HDR technique".


I am simply correcting your error. The only "debate" that's happening is you refusing to acknowledge anything I say, and quoting things that do not support your claim.



It has nothing to do with what "I want" - it has to do with what it actually is.

Or do you support the claim that I swam across the atlantic ocean this summer?


That doesn't mean you're doing HDR. You are compressing the dynamic range to fit your display - that is (again, as I said) the opposite of HDR.



Thank you for providing some citations. As I suspected they are all from people who don't understand the process - there are not domain experts.



True enough. Thank you for reminding me of the importance of tact.

However my first few messages are a testament to the point that no amount of tact will help Civletti to understand what I'm saying - he began with snide comments borne out of Dunning-Krueger ignorance, and continued to in that vein - for example he still insisted that the Wikipedia article he quoted supported his position, when I explained clearly how it did not, and how his chosen source explicitly said he was incorrect.



Yes, and since Racer X 69 explicitly wanted to know how to achieve a certain look (tonemapped) it's important to keep the terminology correct - it does not help him (or anyone else who wants to learn this technique) if the correct information he is given is condescendingly attacked by those who do not understand it.
Forum: Digital Processing, Software, and Printing 01-12-2013, 09:22 AM  
Making HDR Images
Posted By Karl Stevens
Replies: 97
Views: 7,715
The definition I gave is the same as the definition on the Wikipedia page. They are not different. As I said, you need to read it more carefully to understand what is being said.



So experts in the field (including the ones who wrote the software you use) are wrong, but when someone else - whom you refuse to cite or name (presumably because they are not experts in the field) - says the opposite, that makes it true? That is positively absurd.

By the same logic, I went to Europe last summer, so obviously I swam across the Atlantic ocean. It doesn't matter that I was in a plane and didn't get wet, the fact that I left North America and ended in Europe means that I swam there, right?

Exposure fusion compresses the dynamic range from multiple images to fit into a single one. That is the exact opposite of HDR (which - as the name implies - means that the dynamic range is higher, not lower). If it is the exact opposite, it cannot be the same thing.

I realize that it can be embarrassing when you try to correct someone and it turns out that you didn't really understand the topic, but when you do, it's generally the mark of an adult to admit that you learned something, rather than stubbornly insisting that every expert in the field is wrong.
Forum: Digital Processing, Software, and Printing 01-11-2013, 07:10 AM  
Making HDR Images
Posted By Karl Stevens
Replies: 97
Views: 7,715
Then please include a citation for a definition that supports your claim. The wikipedia page you quoted includes only includes one definition, and includes two examples of different methods used to create HDR images, and explicitly says that tone mapping is required for display (correctly implying that exposure fusion is not HDR.)






QuoteQuote:

The two main sources of HDR images are computer renderings and merging of multiple low-dynamic-range [...] photographs. Tone mapping methods [...] facilitate display of HDR images on devices with lower dynamic range



HDR is a process, not a result. If you do not use the process, you are not doing HDR.

(edit)if you had bothered to look up exposure fusion on Wikipedia, instead of stopping at HDR, you would have encountered this:





QuoteQuote:

exposure fusion is a technique for blending multiple exposures of the same scene into a single image. As in high dynamic range imaging (HDRI or just HDR), the goal is to capture a scene with a higher dynamic range than the camera is capable of capturing with a single exposure. However, because no HDR image is ever created during exposure fusion, it cannot be considered an HDR technique.



Also, I looked up the software you use (LREnfuse), and it's a LightRoom front-end for http://wiki.panotools.org/Enfuse
The makers of Enfuse say this:





QuoteQuote:

Enfuse is a command-line program used to merge different exposures of the same scene to produce an image that looks very much like a tonemapped image (without the halos) but requires no creation of an HDR image.



Even the people who write the software you're using say that it is not HDR.
Forum: Digital Processing, Software, and Printing 01-10-2013, 07:36 AM  
Making HDR Images
Posted By Karl Stevens
Replies: 97
Views: 7,715
Tonemapping is absolutely required for HDR - once you create an HDR image you cannot view it without some form of tonemapping. (Unless you have a quarter-million-dollar HDR display from Dolby.)



You do not do HDR, you do exposure fusion. As Eric said, exposure fusion and HDR are not the same thing. While they can provide similar results, they are vastly different processes. HDR imaging creates a mathematical model of the intensity of each pixel in the scene, while exposure fusion blends different exposures into one.


This has adds nothing to the discussion, and is completely wrong - you can make any image "look like cartoons" without tonemapping, and tonemapping does not automatically cause cartoonish images.

If you'd like to clear up your misunderstanding of the difference between exposure fusion and HDR, I'd recommend the following FAQ entry, which is a good primer on how they differ: FAQ about HDR photography software Photomatix - Tone Mapping, HDR images creation and Exposure Fusion.

For a more in-depth discussion of exposure fusion, there DPS has a good article on what exposure fusion is, and how it differs from HDR here: Exposure Fusion: What is it? How does it Compare to HDR? How Do I Do It?
Forum: Pentax SLR Lens Discussion 12-29-2012, 10:03 PM  
Best Pentax lens for stitched panoramic photographs?
Posted By Karl Stevens
Replies: 49
Views: 7,938
Depends on how many photos you want to take, the landscape you're shooting, and whether you're comfortable with multi-row stitching.

Personally, my best panos have been done with the FA 50/1.4 in portrait orientation -
https://plus.google.com/u/0/115017005099942426830/posts/JYHvjwHKbt6

If you use a dedicated pano tool (something like Hugin - Panorama photo stitcher ) distortions will be eliminated when you post-process.

If you're gonna do multi-row, I'd recommend a dedicated panorama tripod head, and the longest lens you have.
Forum: Digital Processing, Software, and Printing 12-27-2012, 03:10 PM  
Making HDR Images
Posted By Karl Stevens
Replies: 97
Views: 7,715
The ethereal/painting look you're talking about comes from tone-mapping, not necessarily from HDR. (If you're doing true HDR, tonemapping is required for display on standard PCs, but you can do tonemapping without doing HDR.)

First thing - make sure you've captured the entire dynamic range of the scene (ie, your shortest exposure needs to have no overexposed areas, and your longest exposure must have no underexposed areas) and shoot RAW (PEF/DNG.) Second, try using a dedicated HDR tool - I recommend Luminance HDR Luminance HDR (it's free, open source, and does a very good job) - Create a new HDR out of your RAW files, then tone-map it with either Mantiuk06 or Fattal, with their default settings (but change the output file size as you like - the default of 256 pixels wide is kinda small.)
Forum: Pentax SLR Lens Discussion 12-22-2012, 04:54 PM  
Anyone waiting for the 10mm Samyang?
Posted By Karl Stevens
Replies: 7
Views: 1,548
Interesting - do you have a source for that? Samyang's Korean site doesn't have a spot for news, and their UK site just mentions "end of 2012" http://www.samyang-lens.co.uk/news.html
Forum: Pentax SLR Lens Discussion 12-22-2012, 09:05 AM  
Anyone waiting for the 10mm Samyang?
Posted By Karl Stevens
Replies: 7
Views: 1,548
Yeah, the press release said it was going to be out for Christmas - still not here.

I love my Samyang 8mm, and a faster rectilinear version would be amazing. Oh well, hopefully it'll be out by my birthday. :)
Forum: Pentax SLR Lens Discussion 12-11-2012, 03:38 PM  
Which lenses are your using for startrails and night sky
Posted By Karl Stevens
Replies: 25
Views: 2,982
Thanks! Some additional info on that image - it's a combination of 8 30-second exposures, aligned with Hugin and stacked in GIMP.

First - it's cheap :) (I also have a limited budget.)

Second was focal length - 8mm is wide enough to get the entire Milky Way (you can see the trees on each side of the clearing at the top and bottom) and the wider your lens, the longer your exposure can be before star trails become apparent. (Formula for APS/C is 300 / focal length, in seconds - so the 8mm can do exposures up to 37 seconds.)

Third, manual focus - AF lenses will focus past infinity, so unless you have something to focus on, it can be difficult to achieve proper focus. MF lenses have a hard stop at infinity, so it's just a matter of turning the focus ring to the end (although when I got it I had to calibrate the Samyang 8mm, which isn't unusual for this lens.)

Drawbacks with the 8mm is that it's a fisheye - so including foreground elements would have been distracting (IMHO) with the curvature (unless I put the horizon in the middle, which I didn't want to do.) At f/3.5 it's also a little bit slow. Samyang announced a 10mm f/2.8 rectilinear this autumn, so if you're going to be buying a lens to do that, I'd wait until that's available to see if its IQ is as good as the 8mm.
Forum: Pentax SLR Lens Discussion 12-10-2012, 03:56 PM  
Which lenses are your using for startrails and night sky
Posted By Karl Stevens
Replies: 25
Views: 2,982
Forum: Pentax K-5 11-14-2012, 05:32 PM  
Pentax K5 II/s in Alberta
Posted By Karl Stevens
Replies: 3
Views: 1,233
Cool - you should bring it to the Rainbow Valley photowalk this weekend so I can gawk at it :)

https://plus.google.com/u/0/events/cc55b4k3sdhk6bcm290am150msc
Forum: Pentax K-5 11-12-2012, 12:33 PM  
K5 extended bracketing
Posted By Karl Stevens
Replies: 6
Views: 2,531
Go into Rec Mode menu -> e-dial programming -> M mode, and set the Green Button function to Tv Shift. (By default it's set to "P-Line".)
Forum: Pentax K-5 10-11-2012, 06:12 AM  
Auto bracket with mirror up
Posted By Karl Stevens
Replies: 5
Views: 896
Hugin does a pretty good job of that. Give each stack a different stack number in the images tab, align the center images and select "exposure fused from stacks" as your output.
Forum: Pentax K-5 10-10-2012, 04:48 PM  
HDR Panorama with K-5 - must use manual lens
Posted By Karl Stevens
Replies: 13
Views: 6,012
You are mistaken. By default, the K7 will use the program line for bracketing in M, and thus vary both shutter and aperture for all exposures in the bracketed set - I know this because it's the absolute first thing I checked when I bought my K7. The Green Button function can be changed on the K7 from Custom Setting 4 menu, but I don't know whether this will affect bracketing exposures.

I have never seen a Pentax camera that operated the way you describe. Every Pentax I've used will vary both shutter and aperture for bracketed images by default. Although some (like the K5 and Km) can be configured to vary only one or the other, I have never seen any setting to tell the camera to vary only shutter or aperture unless it can't achieve the necessary EV.
Forum: Pentax K-5 10-10-2012, 10:47 AM  
Auto bracket with mirror up
Posted By Karl Stevens
Replies: 5
Views: 896
Yes, that's "normal" behavior.


Using live view instead of the 3s delay should keep the mirror up for all shots.



I'm not a big fan of extreme tone-mapping either, but I find enfuse typically leaves the result looking a little flat. I usually tone-map, but turn the settings down to keep it looking more natural. (The new Fattal 06 TMO in Luminance-HDR 2.3 is wonderful at this
- usually turning down the saturation is all that's required to get a nice natural looking image.)
Forum: Troubleshooting and Beginner Help 10-04-2012, 04:38 PM  
Tripod questions
Posted By Karl Stevens
Replies: 2
Views: 782
Looks like a generic laser level tripod. They're sold for around $20 at Rona or Home Depot (including the laser, which fits in the slot to the top.)

There's a DIY project about adapting it for photography here: How to make a low cost panoramic tripod head and how to take 360 degree panoramas
Forum: Pentax K-5 09-24-2012, 12:32 PM  
Comparison of the K-5 Mk II and the 5D Mk III
Posted By Karl Stevens
Replies: 9
Views: 2,616
Not surprising - for the first six months they had the K5 on their site it was listed as "best in class" if you explicitly searched for it, but if you did a general search for recommendations, it never showed up because they had no "online prices" for it. I had to send them the links for Amazon and B&H pages, and a week later it started showing up.
Forum: Photographic Technique 09-18-2012, 09:08 AM  
Exposure bracketing in manual mode
Posted By Karl Stevens
Replies: 9
Views: 2,138
Two instances come to mind.

1. You want to override the camera's meter by more than 5EV.

2. You want to take multiple bracketed stacks and stitch them together. Each stack must use the same exposure values, but you don't want to have to fiddle with exposure compensation for each stack.
Forum: Photographic Technique 09-16-2012, 03:13 PM  
Exposure bracketing in manual mode
Posted By Karl Stevens
Replies: 9
Views: 2,138
In the K5, the decision on whether to change the shutter speed, aperture, or both is controllable via the "green button" setting of the E-dial programming. By default it's set to "P Line", which changes both the shutter and aperture.

To change it, go to Menu 5 -> E-Dial Programming 2 -> "M", and select either "TvSHIFT" (to change only the shutter speed) or "AvShift" (to change only the aperture.)

Happy HDR'ing :)
Forum: Pentax K-5 08-30-2012, 12:43 PM  
HDR Panorama with K-5 - must use manual lens
Posted By Karl Stevens
Replies: 13
Views: 6,012
You're very welcome.. I hope you'll post some of your panoramas to the forums so we can all see them.
Forum: Pentax K-5 08-29-2012, 07:36 PM  
HDR Panorama with K-5 - must use manual lens
Posted By Karl Stevens
Replies: 13
Views: 6,012
No problem, glad to be of help. The manual isn't terribly helpful with this. It's an undocumented feature, so (while disappointing) it's not surprising that Pentax support didn't know about it.

What's probably confusing you is the mention of the green button - you don't actually use the green button, but the setting for the green button affects what the camera does when you're bracketing in M.

So the sequence is simple:
1. Make sure "green button" is set to "Tv Shift" (Camera menu 5 -> E-dial programming 2 -> M)
2. Set camera to mode to "M"
3. Select aperture f/8, and shutter speed of (eg.) 1/250 (or whatever you want for your scene.)
4. Set drive mode to bracketing
5. Take your bracketed set.
6. Recompose for the next set
7. Repeat steps 5-6 until you've got your pano sets.

That's it. The camera will keep the aperture the same for all bracketed shots, varying only the shutter speed. Don't press the green button between sets, or it will change the shutter speed (but you can reset it back to your preferred value as normal.)
Forum: Pentax K-5 08-29-2012, 02:01 PM  
HDR Panorama with K-5 - must use manual lens
Posted By Karl Stevens
Replies: 13
Views: 6,012
This is incorrect. You can set the K-5 to only vary the shutter speed by selecting "Tv Shift" for the Green Button fuction (Rec mode menu, under "e-dial programming".) By default it's set to program line.
Forum: Troubleshooting and Beginner Help 08-06-2012, 07:44 AM  
Exposure Bracketing with controlled conditions for post HDR
Posted By Karl Stevens
Replies: 22
Views: 2,257
To be fair, he was trying to learn - that's why he asked first how to do it on the K-r. It wasn't until he was told it wasn't possible that he said it was a poor design.
Forum: Welcomes and Introductions 07-31-2012, 08:00 PM  
Hi from Alberta Canada
Posted By Karl Stevens
Replies: 5
Views: 386
Welcome - good to see another Pentaxian from Edmonton!
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