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Author Topic: how many bracketed pictures for interior hdr processing?  (Read 35117 times)

Ellis Vener

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Re: how many bracketed pictures for interior hdr processing?
« Reply #20 on: July 09, 2015, 12:35:38 pm »

How many bracketed pictures do you take to do HDR for complex interior spaces? Also, what increments do you use? Can you get away with shooting 7 pictures at 1.6 stop increments and get the same quality HDR file as you have shot 11 pictures at 1 stop increments?

Thanks

I t wil depend on the luminance range of the scene and the dynamic range of the sensor. I prefer to do my HDR shooting in one stop increments from -4.0 to +4.0.   While this vastly exceeds the normal luminance range of almost all subjects  it also allows me to decide which subset of those images will make the best composite.

My favorite Lightroom too  for extended dynamic range work, especially for architecture and real estate work where pleasing and realistic color is preferred over the acidic candy colored distorted  look is Timothy Armes'  Enfuse plug-in from http://photographers-toolbox.com/products/lrenfuse.php

Armes also recommends this e-book http://photographyforrealestate.net/enfuse/ by Simon Maxwell.  After reading for the past few days I concur with his assessment.

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caribsurf47

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Re: how many bracketed pictures for interior hdr processing?
« Reply #21 on: July 09, 2015, 01:06:08 pm »

Interesting and worth investigating, especially as I have LR6 anyway. The Photo Merge to HDR offering in LR6 is "ok" but it does not really offer the degree of fine tuning that I would like. With Photomatix one does have to reduce the suggested defaults by a considerable degree and my suspicion is that many just don't bother. As presented, they can produce some OTT results. I will have a closer look at your suggested Plug In. When shooting interiors where you are presented with a host of natural and artifical lighting, adjusting the Colour Temperature of your Frames can be very important. I suspect that many individuals shoot on Auto White Balance and do not alter the sometimes variable and unrealistic Colour Temperatures that the camera selects. I try to remember the type of stone used and work with that as a basis for any alterations.
« Last Edit: July 09, 2015, 01:12:33 pm by caribsurf47 »
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caribsurf47

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Re: how many bracketed pictures for interior hdr processing?
« Reply #22 on: July 17, 2015, 05:43:36 am »

Here's one that may surprise you. Six RAW frames shot in 2013 from a Panasonic LUMIX DMC LX3 camera inverted on a tripod. The 0EV was shot at 5.1mm, ISO 125, f/2 and 1/30sec. Many people would write off this little camera as too inexpensive to be any good. I would love the to try the LX100 with the larger Sensor. The RAW conversions and Geometric corrections were made in LR6 and I then used the Photo Merge to HDR utility. This is the beautifuiiy vaulted ceiling of the 12th century abbey at Malmesbury in Wiltshire, England. The 16-Bit Master File holds up quite well to a close examination @ 100% and probably would print well.
« Last Edit: July 17, 2015, 05:48:17 am by caribsurf47 »
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ErikKaffehr

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Re: how many bracketed pictures for interior hdr processing?
« Reply #23 on: July 17, 2015, 06:22:34 am »

Hi,

My personal experience is that two or three exposures, three to four EV apart, can be quite enough. I am pretty sure that has also been indicated by Jeff Schewe and Eric Chan.

I don't do HDR very often, but I found that the in Lightroom 6 does a very good job. LumaRiver HDR is also a program that I found much to my liking.

Best regards
Erik
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Erik Kaffehr
 

caribsurf47

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Re: how many bracketed pictures for interior hdr processing?
« Reply #24 on: July 17, 2015, 09:56:46 am »

Thanks Erik, I will have a look at your recommended HDR software.
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Abdulrahman Aljabri

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Re: how many bracketed pictures for interior hdr processing?
« Reply #25 on: August 08, 2015, 02:23:14 pm »

Thanks to everyone for their feedback.

I did some extensive testing while shooting my projects. I mainly used the Canon 5D mark 3 files and on some occasions the Sony a7r. All the files were processed using Adobe Photoshop CS6 Merge to HDR tool in 32bit mode and saved as tiff.

I think as most have pointed out there is no set number of pictures that will achieve the best results. I found that exterior architecture pictures in sunset do not require more than 7 stops range. On the other hand some interior spaces required 11 stops range to capture the difference between shadows and inside and highlights out side in the view. 

Most often I required more negative exposures than bright ones. For example with the exterior picture I did not need more than +2 for the shadows but needed -4 to tame down the bright light sources.

One interesting observation was that I found adding too many bright exposures caused banding in white walls. Sometimes adding extra bright exposures is needed because the shadows are too dark and the extra information from those files will improve them. The solution is to create two HDR files and blend different parts with masks in photoshop.

All in all I find my self shooting from 7 to 11 exposures to capture the entire range and in 1.3-1 stops increments to insure the smoothest results. 

Increments wise, there isn't really much difference between 1.3stops and 1stop. You can shoot 7 1.3stops exposures and obtain the same results from 9 1stop exposures. I just find shooting single exposures easier to calculate. However, 1.6 and 2stops provides less clean results. For example, with equal exposure range you will be able to brighten shadows to the same extent but the shadows will be a little less smooth.   
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Guillermo Luijk

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Re: how many bracketed pictures for interior hdr processing?
« Reply #26 on: August 10, 2015, 09:58:33 am »

All in all I find my self shooting from 7 to 11 exposures to capture the entire range and in 1.3-1 stops increments to insure the smoothest results.  

Increments wise, there isn't really much difference between 1.3stops and 1stop. You can shoot 7 1.3stops exposures and obtain the same results from 9 1stop exposures. I just find shooting single exposures easier to calculate. However, 1.6 and 2stops provides less clean results. For example, with equal exposure range you will be able to brighten shadows to the same extent but the shadows will be a little less smooth.

Can you show an example that demonstrates that the shadows are less smooth when shooting at 2 stops invervals than when doing it at 1 stop intervals? or it is just a perception you have?.

On the other hand, more shots also mean a higher risk of losing sharpness. Unless your images are perfectly aligned, something very difficult to achieve even if you align them in software (real world is not subject to perfect 1-pixel shifts), the more shots you do the more areas in the final composite will be provided by a blending of 2 or more shots, and these progressive areas will loose sharpness.

This is a sample of a HDR machine-gun-shooter guy trying to convince others that the more shots the better. He provided an image where using 7 shots was less sharp than using just 3 shots:



Regards!

« Last Edit: August 10, 2015, 10:00:14 am by Guillermo Luijk »
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hjulenissen

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Re: how many bracketed pictures for interior hdr processing?
« Reply #27 on: August 11, 2015, 03:45:25 pm »

...You'll not only get the same quality with 7 pictures at 1,6 intervals than with 11 at 1 stop intervals, but the same with 4 pictures at 3 stops intervals.
http://www.sns-hdr.com/forum/viewtopic.php?f=7&t=4138
Quote
The gradients are less precise when the step is large. I do not recommend step greater than 2ev.
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hjulenissen

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Re: how many bracketed pictures for interior hdr processing?
« Reply #28 on: August 11, 2015, 03:50:22 pm »

I saw some paper where they estimated the DR of some lens on a Canon 20D to be limited to 10-20 stops due to flare, depending on the size of the bright patch (a single bright dot giving the largest DR).

When your lens is limiting DR, exposure bracketing wont fix it.

-h
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AlterEgo

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Re: how many bracketed pictures for interior hdr processing?
« Reply #29 on: August 11, 2015, 05:44:11 pm »

http://www.sns-hdr.com/forum/viewtopic.php?f=7&t=4138
specifics of that particular application ? did you notice bad gradients with Fuji raws where masked sensels were separated by more than "step greater than 2ev" ?
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ErikKaffehr

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Re: how many bracketed pictures for interior hdr processing?
« Reply #30 on: August 12, 2015, 12:58:45 am »

Hi,

There was a thread discussing that issue. Iliah Borg said that captures would be limited to 11EV due to lens flare. I doubt that figure is absolute, but 11 EV essentially lies in line with what I can see in RawDigger in most of mine high luminance range of images.

The included single exposure image is quite OK, but noise in the darks is a bit high, still manageable with noise reduction. HDR version gives better shadow detail. Shadow detail is often not very visible so it can often take a lot of noise reduction.

Best regards
Erik


I saw some paper where they estimated the DR of some lens on a Canon 20D to be limited to 10-20 stops due to flare, depending on the size of the bright patch (a single bright dot giving the largest DR).

When your lens is limiting DR, exposure bracketing wont fix it.

-h
« Last Edit: August 12, 2015, 01:15:52 am by ErikKaffehr »
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Erik Kaffehr
 

ErikKaffehr

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Re: how many bracketed pictures for interior hdr processing?
« Reply #31 on: August 12, 2015, 01:24:43 am »

Hi,

My take is really that we need one image exposed for the highlights, with essentially no clipping. Raw processors don't give useful indications on clipping as they can apply both curves and tone mapping to the histogram. Using a tool like RawDigger gives accurate info. Personally I find that in camera histograms are accurate enough for me.

Than I need at least one exposure for good detail in the darks. I would say Guillermo has a good point on having fewer images may be better. I would also guess that it can depend on software. Also, having more exposures can help with ghost elimination but also create more ghosts to eliminate.

Software may also matter. I mostly used the HDR built in Lightroom, but I also have Lumariver HDR and of course the one in Photoshop.

Best regards
Erik

Thanks to everyone for their feedback.

I did some extensive testing while shooting my projects. I mainly used the Canon 5D mark 3 files and on some occasions the Sony a7r. All the files were processed using Adobe Photoshop CS6 Merge to HDR tool in 32bit mode and saved as tiff.

I think as most have pointed out there is no set number of pictures that will achieve the best results. I found that exterior architecture pictures in sunset do not require more than 7 stops range. On the other hand some interior spaces required 11 stops range to capture the difference between shadows and inside and highlights out side in the view.  

Most often I required more negative exposures than bright ones. For example with the exterior picture I did not need more than +2 for the shadows but needed -4 to tame down the bright light sources.

One interesting observation was that I found adding too many bright exposures caused banding in white walls. Sometimes adding extra bright exposures is needed because the shadows are too dark and the extra information from those files will improve them. The solution is to create two HDR files and blend different parts with masks in photoshop.

All in all I find my self shooting from 7 to 11 exposures to capture the entire range and in 1.3-1 stops increments to insure the smoothest results.  

Increments wise, there isn't really much difference between 1.3stops and 1stop. You can shoot 7 1.3stops exposures and obtain the same results from 9 1stop exposures. I just find shooting single exposures easier to calculate. However, 1.6 and 2stops provides less clean results. For example, with equal exposure range you will be able to brighten shadows to the same extent but the shadows will be a little less smooth.    
« Last Edit: August 12, 2015, 01:27:30 am by ErikKaffehr »
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Erik Kaffehr
 

Guillermo Luijk

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Re: how many bracketed pictures for interior hdr processing?
« Reply #32 on: August 13, 2015, 08:14:45 pm »

Quote from: hjulenissen
link=topic=101682.msg843983#msg843983 date=1439322325]
http://www.sns-hdr.com/forum/viewtopic.php?f=7&t=4138

"The gradients are less precise when the step is large. I do not recommend step greater than 2ev."

Sebastian, SNS-HDR's author, is surely right just by adding "when using SNS-HDR" to his claim. This also happens with Photomatix and other blending algorithms like Enfuse's pyramids. But this is a fault of those pieces of software, which are sub-optimum at the blending stage doing quite extensive progressive blending, it is not a general truth about bracketing fusion.

Sub-optimum progressive blending algorithms have two consequences: they fail to get the best available information from the input RAW files so they need more shots for the same output blending quality, and they loose sharpness when a minimum missalignment between shots persists.

With modern sensors (and not so modern as my Canon 350D's), gradients are fine at 4 stops intervals, although I prefer not to go that far and bracket at 3 stops intervals.

Regards

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