Hdr?

[ibogost]

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I agree that "disturbing" and "unreal" are accurate words to describe most HDR shots. Here's one I actually constructed out of three exposures. It's not really a good photograph, but maybe it's an example of a less disturbing use of HDR. The last one is the HDR composite.

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[Philinflash]

I agree that "disturbing" and "unreal" are accurate words to describe most HDR shots. Here's one I actually constructed out of three exposures. It's not really a good photograph, but maybe it's an example of a less disturbing use of HDR. The last one is the HDR composite.

 

Ian, your photo may not get you a membership offer from Magnum, but it does a good job of illustrating the application of HDR magic, thanks!

 

I have tried it from a single DNG file in PS CS3 with a nil result. I suspect the reason is that the metadata exposure adjustment information did not get imported into PS along with the DNG files.

 

I took the "as shot" DNG file, saved it as a new DNG file and then made four adjusted files (all saved with different names) representing +.75, +1.50, -.75, and -1.50 exposure adjustments. When it all came up in the "Merge to HDR" pane of PS, it was just the same as the "as shot" base file. There were five thumbnails representing all the files but they were all at the same EV (0.00) and, of course, they all looked the same. So, I conclude that you cannot use a single DNG in PhotoShop's HDR.

 

That is not to say that other apps won't take the exposure metadata into account for HDR processing. That would be nice.

[ibogost]

Yeah, I've never tried it in Photoshop, only in Photomatix. Photomatix lets you set the EV metadata if its not embedded in the files. It also tries to guess from the comparative exposure.

[Guest sirvine]

On the M8, I think the biggest benefit of a multi-exposure HDR composite is going to be less noise in the shadows. I'm pretty sure you could come very close to the fourth image by tweaking the third image in RAW processing properly, but you might have more noise in the shadows (esp. color noise).

[ibogost]

On the M8, I think the biggest benefit of a multi-exposure HDR composite is going to be less noise in the shadows. I'm pretty sure you could come very close to the fourth image by tweaking the third image in RAW processing properly, but you might have more noise in the shadows (esp. color noise).

 

I tend to agree with this too.

[ChrisC]

........ I conclude that you cannot use a single DNG in PhotoShop's HDR..

 

Philip - Wow. I am stunned by this news, it's extremely disappointing. Does this also mean that the panorama stitching in CS3 also does not function with M8 files? I do not yet have CS3, has anyone tried stitching CS3 panoramas [is it called Photomerge?]

 

................Chris

[Philinflash]

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....

Does this also mean that the panorama stitching in CS3 also does not function with M8 files? I do not yet have CS3, has anyone tried stitching CS3 panoramas [is it called Photomerge?]

 

................Chris

 

No, no, no, don't panic!

 

Photomerge works a treat.

 

I don't think my experience with HDR conversion is M8-related; I think it is just the way CS3 is designed. It seems to require DNG files that are identical in all aspects except exposure in the base file as opposed to in the metadata files. However, without an automatic bracketing facility on the M8 we are disadvantaged in that sense because that is hard to achieve in the field where the M8 is most at home.

[Philinflash]

Further to whether PS CS3 Photomerge works see the image below.

 

It is made up of five different shots. These was necessary because the ancient monuments preservation on this Mexican site mandated comprehensive light-sheilding measures that meant that there was no single vantage point that allowed photographers to take in the whole wall. At least not with my 35mm.

 

[ChrisC]

Philip - Thank you for taking the time to reassure me about Photomerge. I had read the thread too hastily, whilst I had planned to use HDR from multiple M8 RAW developments from the same image file [as in the discussion], I also planned to use it to combine separately exposed files with different EV compensations when doing tripod work; should that work OK?

 

.......................Chris

[Philinflash]

...

 

I also planned to use it to combine separately exposed files with different EV compensations when doing tripod work; should that work OK?

 

.......................Chris

 

Yes, that should work perfectly. In addition to referring to what I see within the application, I am also looking at Martin Evening's book, "Adobe Photoshop for Photographers," which discusses it at some length. I am entirely confident that it will work in your context.

[Artichoke]

I haven't looked at this Photomatix software. I note that PhotoShop CS3 has HDR capability, although I have not tried it yet. Artichoke, have you tried the PS? If so, do wish to draw any comparisons?

 

BTW, your posted image looks more like HOWston than HEWston.

 

comparisons: PS does not offer as many options for doing the conversions & requires more prep if doing dual conversions from a single RAW file "developed" as different exposures

the files produced from Photomatix seem better as well, though with so many options available to do the conversions, it is difficult to compare ...the software is a bit pricey as it only does one thing, but it does do this quite well and with little work

regarding the locale of the posted image ...this was taken south of Houston Street, by about 1/2 mile, not far from NYC's City Hall ...my home town of Houston does not offer such vistas

[rob_x2004]

Ian your link 21, if you are getting the fourth image from the first three, is a much better example than the first posts and a decent demonstartion of using HDR effectively. Though I still find the third frame more natural looking. Can you also apply a mask to problem areas so that you can apply HDR selectively within a frame?

[ibogost]

Ian your link 21, if you are getting the fourth image from the first three, is a much better example than the first posts and a decent demonstartion of using HDR effectively. Though I still find the third frame more natural looking.

 

The third frame definitely looks more natural. But if I hadn't shown it to you, you might think the HDR image looks credible.

 

Can you also apply a mask to problem areas so that you can apply HDR selectively within a frame?

 

I don't know how to do this, but a computer graphics colleague of mine would. I'll ask him.

[Philinflash]

comparisons: PS does not offer as many options for doing the conversions & requires more prep if doing dual conversions from a single RAW file "developed" as different exposures

the files produced from Photomatix seem better as well, though with so many options available to do the conversions, it is difficult to compare ...the software is a bit pricey as it only does one thing, but it does do this quite well and with little work

regarding the locale of the posted image ...this was taken south of Houston Street, by about 1/2 mile, not far from NYC's City Hall ...my home town of Houston does not offer such vistas

 

I don't get how you do "dual conversions from a single RAW file" in Br/Ps. When I did that in Br and imported the files into Ps, the development data was ignored by Ps. Could you please provide a little more guidance on how you do that? I must be doing something wrong.

 

I downloaded the Photomatix Beta but I haven't played with it enough to "get it."

 

I was just ragging you about Houston; I know very well where your shot was taken, although I life a few miles from there.

[Jamie Roberts]

A couple of points...

 

First, the dynamic range of the m8--particularly in the shadows at ISOs 640 and under, is where you're going to get the most bang for the buck for sure.

 

Secondly, you cannot do an HDR mapping in Photoshop *automatically* because PS was essentially looking at the EXIF data for, IIRC, at least 1EV's worth of difference. They weren't really thinking RAW latitude or 14bpp sensors when they designed it So even with a Canon RAW file, you need three separate exposures. It's not an M8 limitation at all.

 

Of course you do a manual HDR merge by making 2 or 3 (or even four, sometimes) RAW conversions into JPEGs or TIFFs then compositing them in PS, where you can use masks and so on.

 

The trick to getting a natural result on a non-HDR device (like a monitor) is to create curves that fall within the DR of the output device.

 

Think about it--you do this all the time when you limit how much black gets laid down in an inkjet or lab print (and you do a similar thing with colour gamut too).

 

So you can always manually do this.

 

The most flexibility with the M8 comes from three exposures--one to safeguard the upper highlights (not the speculars--let them blow, IMO); one for midtone detail (where hte highlight detail is gone and one for shadows (where the midtones are now upper midtones).

 

Compositing that and converting to BW gives exceptionally good results, IMO. (Black and white gets rid of a lot of colour compositing artifacts; midtones do shift and it's tricky work).

 

The BWs look completely "believable" to my eyes with relatively little effort...

 

Just for giggles, do your best straight BW conversion on the "normal" and the "Hdr" one above. I can tell you which one looks more like something I'd see in a darkroom for printing Interesting, no?

[Kent10D]

Interesting, no?

 

Interesting ... yes!

 

The idea of using HDR for B&W simply never occurred to me ('scuse me while I kick myself).

I'll definitely have to try that.

 

Thanks for the tip!

 

Kent.

[Philinflash]

A couple of points...

 

First, the dynamic range of the m8--particularly in the shadows at ISOs 640 and under, is where you're going to get the most bang for the buck for sure.

 

I am not sure what you mean by the above. Are you saying there is a DR deficiency about the M8 that especially benefits from compositing in HDR?

 

 

...

 

Of course you do a manual HDR merge by making 2 or 3 (or even four, sometimes) RAW conversions into JPEGs or TIFFs then compositing them in PS, where you can use masks and so on.

 

Are you saying in essence make, say, 3 JPEG conversions and then composite those into HDR? I tried that with horrible results. Perhaps TIFFs would be better with less compression(?).

 

...

 

The most flexibility with the M8 comes from three exposures--one to safeguard the upper highlights (not the speculars--let them blow, IMO); one for midtone detail (where hte highlight detail is gone and one for shadows (where the midtones are now upper midtones).

 

Agree. I cannot see a material benefit for more than 3 exposures, if those are at the right points.

 

 

Compositing that and converting to BW gives exceptionally good results, IMO. (Black and white gets rid of a lot of colour compositing artifacts; midtones do shift and it's tricky work).

 

The BWs look completely "believable" to my eyes with relatively little effort...

 

Just for giggles, do your best straight BW conversion on the "normal" and the "Hdr" one above. I can tell you which one looks more like something I'd see in a darkroom for printing Interesting, no?

 

I had thought about B&W HDR but my greater need is in color.

[Jamie Roberts]

I am not sure what you mean by the above. Are you saying there is a DR deficiency about the M8 that especially benefits from compositing in HDR?

 

No, I'm saying there is a DR *surplus* in the M8 that is hard to wrangle without some HDR techniques in scenes that warrant it. Let me be clear: it's usually never necessary, given that you know what you're doing with a good TIFF file in PS.

 

But it can save you years of your life in PS if you know how to do this, and the M8 (unlike a lot of other cameras, in my experience) actually repays the time investment in doing this, even to the point of being able to do a *lot* from a single DNG.

 

Are you saying in essence make, say, 3 JPEG conversions and then composite those into HDR? I tried that with horrible results. Perhaps TIFFs would be better with less compression(?).

 

Yes, that's what I'm saying, in essence. I'm not sure what "horrible" means for you, but I'm assuming that it can mean JPEG artifacts; mis-matched colour, or compositing problems.

 

The devil, as always, is in the details Assuming colour, then...

 

1) if you're getting artifacts, that's easy. Convert to a TIFF instead. And personally, I'd convert to a 16bpp TIFF. Why? Some RAW converters are not so hot at making 8 bit files from RAW, and they're none of them as good as Photoshop Well, maybe C1 is, to the right profile.

 

So two or three 16bpp TIFFs, if colour is what you want/.

 

2) If you're going to do this in colour, then you need to use a good RAW conversion program (C1 would be my choice) and you need to do *very, very little* manipulating of the image. No midtone shifts / curves Exposure compensation whatsoever, because they will induce subtle colour shifts that will only be exaggerated by PS and putting the files together.

 

But you need to make sure the appropriate white balance is the same, of course, for all the files.

 

3) You then input to photoshop, convert immediately to 8 bits unless you're doing something extreme with skies (and you might be... so buy some more memory ) and composite.

 

Now is the time to learn about layer and channel masks, honestly. But you can still do a good job just with the erase tool and and layer opacity. Try it!

 

Now, in B & W--you can be much more cavalier about processing.

 

In C1, click the "preview in BW" button and go for tonality--pure and simple. Who cares what the actual colour is, as long as the WB is relatively the same ?

 

So I hope this helps. Practice makes perfect. When I first started doing this (by necessity) with my Canon cameras, the first outings were pretty horrible looking.

[Jamie Roberts]

Interesting ... yes!

 

The idea of using HDR for B&W simply never occurred to me ('scuse me while I kick myself).

I'll definitely have to try that.

 

Thanks for the tip!

 

Kent.

 

Kent--it's one of the first things I inadvertently discovered figuring out how to make the M8 fail in edge light conditions. The results in BW with three "develops" from the same RAW--or from three exposures--are really very good.

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[Philinflash]

Jamie,

 

Thanks for your detailed and thoughtful responses. Below, I am commenting on some of your observations.

 

No, I'm saying there is a DR *surplus* in the M8 that is hard to wrangle without some HDR techniques in scenes that warrant it. Let me be clear: it's usually never necessary, given that you know what you're doing with a good TIFF file in PS.

 

I preliminarily agree, although I do not really have enough HDR experience under my belt to go too far down that road.

 

 

I'm not sure what "horrible" means for you, but I'm assuming that it can mean JPEG artifacts; mis-matched colour, or compositing problems.

 

 

First of all, the results were not as good as I could achieve using various conventional techniques in Ps. Maybe "horrible" is hyperbole. If it wastes my time, it is horrible. But also, there was actually loss of details and gross over-exposure. Perhaps that was because I was working from a single RAW file before going to JPEG or TIFF multiple-exposure derivatives. I will have to try HDR working from multiple RAW files exposed at various EVs.

 

I have convinced myself that there is little point in trying to force single RAW files through the HDR process. But if the HDR process is undertaken on multiple files, it seems to me that the conversion should be the first post step for an image with a problematically wide DR. But, as you imply, the M8's range should mean that there are not many of these.