Camera Labs

Thanks for the kind words. The worst noise is in the furthest hills on the left. I left it in the finished picture (posted in the Landscape section) because I felt that removing the noise left that area looking a little too devoid of "detail".

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Nice shot. It does prove that its possible, although when viewed at 50% crop or above, you do start to notice that the shot has been taken hand held.

Can i just ask...if you are taking a landscape shot, with 3 exposures, the faster you camera can take pictures, e.g. 2.4fps, 6.5fps etc. then does this mean that any errors caused by leaves moving etc will be reduced if the shutter speed is quick enough?

E.g. - 40D @ 6.5FPS - 3 images, 1 @ 1/400 2@ 1/800 3@1/200 - This would all be done in under 1/2 a second? instead of over 1 second for my 350D?

(sorry that was a little off topic, but it was really bugging me)

I'll try and experiment also with HDR shots over the next 2 weeks since we have the 2 week October break starting today

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Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L USM + Canon 24-70 F/2.8L USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
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It was a windy day and I believe some of the artefacts in the foreground (bottom left) may well have been caused by that. If you look closely some leaves have been doubled up while nearby branches haven't. Some of the thinner branches are also a little fuzzier than in the 0ev original though I think this area was just a bit too close to be in really sharp focus even at f/9. There is also some chromatic aberration which I guess is down to the lens and that slight lack of focus. Objects in the distance (the white houses are an example) have been aligned to the pixel. Try pixel peeping the field with the sheep at the far end of the lake in the 0ev original here compared with my final image here. To my eye the sharpened final HDR image actually looks sharper than the original one.

Looking at the untrimmed picture size as output by Photomatix it seems that the original three pictures were already aligned to within 10 pixels vertically and just three pixels horizontally so I don't think that using a tripod would have made a huge difference to the final result this time. Having a fast burst speed from the camera presumably helps and the weight of the 40D plus my 24-105 lens can't have hurt either.

I don't see how any HDR software can "know" that a leaf which appears in two different places in successive frames is actually the same leaf and so "knows" to output just the one. My take on this is that it is a fundamental limitation of AEB/HDR. It would be really nice if the manufacturers could produce sensors capable of capturing the full dynamic range of an AEB sequence with just a single exposure. IMO that would be a far more valuable feature than increasing the megapixel count and then we could give every picture we take as much or as little HDR and tone-mapping processing as we want.

Bob.

P.S. I thought you were right on-topic as this thread seems mostly to be about the perils and pitfalls of how HDRs are made. If it isn't then it is my posts which are off topic!

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

I think Thomas has mentioned that there is at least one camera (obviously not a typcial DSLR lol) that has a HDR Sensor in it, but you pay for it apparently!

HDR sensors would be a dream come true for some photographers, especially ones that do weddings, I know simply example, but the white on the brides dress, and the black on the grooms suit jacket, are a massive contrast, bringing most DSLR's to their knees! (Maybe the 1DsMKIII could cope a bit better, but still) Medium Format cameras again, could maybe handle this better, but still its not HDR!

The main problem with HDR sensors is its a little like, from what I understand, trying to create the range of tones and contrast that the human eye can understand, as the human eye does have a High Dynamic Range.

I think HDR photos could be achieved in a wedding portrait of the bride pretty well, if the subject sits or stands still enough, and the camera in question can take the 3 exposures quick enough (under 0.5 seconds) then it would be sharp enough to please some of the pixel peepers, and also give you the high dynamic range which is much needed in things like that, else the fine detail in the dress is lost, or the face is to dark.

I think it will be a good 5-10 years before we start seeing True HDR sensors hit the market for DSLRs, but I do not doubt that we will see HIGHER dynamic range sensors that we have just now. It's not going to be like a jump from 10,000:1 contrast, to 10,000,000:1 contrast overnight (or w/e the contrast ratios are - just guesses lol) it will be a gradual increase, just like the megapixel fad has been.

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Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L USM + Canon 24-70 F/2.8L USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
Cactus V2s Wireless Trigger - 5 x Cactus V2s Wireless Reciever

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Hi Daniel,

Good points. I don't know why HDR sensors should be so difficult to do (particularly with the deeper wells of FF chips) but it either is difficult or there isn't enough demand. In the meantime there's the 40D's Highlight tone Priority which apparently helps with things like bride's dresses. I haven't had any success with it in my brief trial so as I prefer to shoot at ISO 100 where possible (HTP has a minimum ISO 200) I haven't experimented any further.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

ISO 200 should be fine for most shooting, not much noise at 200 or indeed 400 on the 40D is there?

I thought I had heard something about the 40D having a feature like that but didn't mention incase it was just something I made up in my head lol!

well, whenever you give it a try out, do post, as I am really interested in that

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Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L USM + Canon 24-70 F/2.8L USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
Cactus V2s Wireless Trigger - 5 x Cactus V2s Wireless Reciever

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I've yet to read a decent explanation as to why I have to take 3 separate exposures in the first place. Why can't the camera just write 3 individually exposed files from the one source exposure? Seems straightforward to me, what do I know, lol.

As for trees, avoid them. Wind, ditto. Both together, take the day off and go to the pub, lol.

Zorro

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Various lenses, SB800 & Manfrotto 190 with 460MG head

Hi Zorro,

While waiting for some intensive astro-imaging manipulations to complete I had another look at Christian Buil's page discussing the merits of the 40D for astrophotography. About halfway down this page there is an untranslated paragraph in French which starts "Au passage, tachons de tordre le cou à une idée reçue...". If your French is as bad as mine it is worth running through a machine translator (Google etc.).

He starts by stating that for the low light situations typical of astrophotography "the choice of ISO has virtually no impact on the "sensitivity" of the camera". If I understand the machine translation correctly he then goes on to remark that for everyday photography the only reason an ISO setting is useful is that it allows the 12 (or 14) bit signal from the camera's sensor to be mapped into the 8 bit signal stored in JPEGs.

The implication is clearly that, particularly with 14 bit A/D converters on the sensor, if you can work directly with the RAW file data it is possible to extract the extra information that would otherwise have needed an AEB sequence. Presumably the trick is to get the camera to let just enough light fall on the sensor so that the highlights just fill the relevant pixel wells while using an ISO setting, and so controlling the readout amplifier gain, that means that a full well is converted into "4095" for 12 bit A/D conversion and "16383" for 14 bit conversion.

If this analysis is right then the big questions are:

1. Why don't DSLR manufacturers provide an optional override to automatically expose this way? Applying a blanket +2ev value to each exposure won't work because the amount of overexposure needed to achieve a full well on the brightest lit pixels is scene dependant.
2. Is there any software out there that can already process RAW files in the way needed? My guess is that there is, but the functionality isn't promoted because cameras generally don't exposure in the optimal way.

Maybe those two glasses of wine mean that I am spouting even more tosh than usual. Any thoughts, anyone? No, not about how much tosh I usually write!

Bob.

EDIT: Spelling correction

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Now that's very interesting: Zorro is doing the greatest HDRs here and has no idea how it works.
That clearly shows that you don't need to be a rocket scientist to make excellent photos
And this in turn should give hope to us all

Well, well, well. The x different exposures have to be made, because the overexposed pics lose detail in the highlights (resulting from limited well-capacity) and the underexposed pics lose details in the shadows (resulting from too little distance from zero).

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Disclaimer: I still make worse HDRs than Zorro
And no, I'm not a rocket scientist either

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Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

I can open an image in Capture NX and "correct" the exposure either way, sometimes to a surprising degree. I don't see why the same thing isn't possible in-camera.

Zorro.

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Various lenses, SB800 & Manfrotto 190 with 460MG head

The Nikon RAW has amazing capabilities, and that's what PhotoMatix is using, when they do HDR from a single RAW/TIFF. But still it's limited by the range that the sensor can capture.
Let's assume that ( the sensor range that is) is 10bit. This gives you 2 stops headroom when converting to jpeg 8bit (thus the ability of CaptureNX to draw these 2 stops out of the RAW/NEF). So with derivatives from a single exposure, you're limited to 2 stops enhanced range. With a +-2EV exposure you extend these limits by another 4 stops, and that's much more headroom that PhotoMatix can play with.
This should be the major (technical) reason, why your HDRs look so excellent, Zorro.
With "single file conversion" (in PhotoMatix) you'd certainly end up with HDRs that don't have the same "depth". And if you just process two +-2EV tiffs from a single NEF in CaptureNX and feed this into PhotoMatix (instead of 3 differently exposed pics), the result should be similarly limited

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Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

I must confess I hadn't thought about that Thomas. I have tried the single file conversion method in Photomatix and you're right, the results are pretty terrible.

There seems to be two distinct ways of using HDR techniques emerging. One which genuinely tries to evenly expose the whole image in a realistic way, as evidence in some fine pictures above - and another, more "out-there" approach which basically accepts whatever looks good, not necessarily what looks right. Or something like that, lol. I know what I mean anyway.

I'd be interested in opinions of a shot I took today. How far is too far? Another thing that's interesting is that while my Sigma 10-20mm is an outstanding landscape lens, it is not ideally suited to the vagaries of HDR processing. Pay particular attention to the vignetting as an example, this is after lens correction in PS CS3! Not great. Another thing, is the burn-out in the central portion of the sky acceptable? I'm not sure about that either, lol.



Zorro

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Various lenses, SB800 & Manfrotto 190 with 460MG head

Anyone like to show me how I make a clickable link to the above image in Flickr?

Zorro.

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Various lenses, SB800 & Manfrotto 190 with 460MG head

Zorro that is amazing! Some burn out is needed to emphasize how bright it was.

Amazing image Zorro, damn you and your HDR ways!

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Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L USM + Canon 24-70 F/2.8L USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
Cactus V2s Wireless Trigger - 5 x Cactus V2s Wireless Reciever

MY FLICKR!

Wow Zorro that's really fantastic. Looks like some of the dramatic landscapes people make with Terragen. I never thought it would be possible capture something like that in a photograph even a HDR. Really nice!

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Graham
Flickr