dpreview 40D review! just posted :D

AngryCorgi wrote in post #4190909
The HTP feature appears quite useful and is shown off in an over-exposed image (HTP feature segment) and then in adjusted the exposure in software afterward. It also seems to apply to RAW files too, which is nice.

Sorry, but this is not true. The RAW file (which has been exposed at 1/2 the set ISO) carries a metadata tag that triggers the use by DPP of an alternate tone curve that pushes the mid to darker tones by one stop but preserves the highlights. Open it in a third party converter and all you get is an underexposed image. However, if you have a converter that enables you to design your own tone curve, you can do the same thing and maybe better since you have more control than by using DPP's preset.

I'm not a pixel peeper, and my images from my 30D and 40D are identical in print. I sold one of my 30D's to help fund the upgrade to a 40D. My desire to do so was based on the AF system of the 40D. IMO, it is FAR more accurate and consistent than that of the 2 30D's I own(ed). It always baffles me why people are constantly discussing IQ with every new camera that comes out, as if it is the only reason one should upgrade.

tzalman wrote in post #4194403
Sorry, but this is not true. The RAW file (which has been exposed at 1/2 the set ISO) carries a metadata tag that triggers the use by DPP of an alternate tone curve that pushes the mid to darker tones by one stop but preserves the highlights. Open it in a third party converter and all you get is an underexposed image. However, if you have a converter that enables you to design your own tone curve, you can do the same thing and maybe better since you have more control than by using DPP's preset.

Well, I don't know the technicalities, but in practice, I found that HTP works very well on raw files in Lightroom when using the recovery slider. It recovered more highlights in LR than was possible in DPP - for the same photo. YMMV.

BogongBreeze wrote in post #4194474
Well, I don't know the technicalities, but in practice, I found that HTP works very well on raw files in Lightroom when using the recovery slider. It recovered more highlights in LR than was possible in DPP - for the same photo. YMMV.

Well sure, LR has excellent highlight reconstruction and DPP doesn't have any at all. And if you had highlight loss in DPP even with HTP on, you were so overexposed that even HTP's 1 stop reduction couldn't save you, but LR did.

OTOH, if one wants to use DPP (and there are good things that can be said about it) enabling HTP and exposing to the right in order to utilize that extra headroom can produce very nice highlight tonal transitions.

tzalman wrote in post #4194403
Sorry, but this is not true. The RAW file (which has been exposed at 1/2 the set ISO) carries a metadata tag that triggers the use by DPP of an alternate tone curve that pushes the mid to darker tones by one stop but preserves the highlights. Open it in a third party converter and all you get is an underexposed image. However, if you have a converter that enables you to design your own tone curve, you can do the same thing and maybe better since you have more control than by using DPP's preset.

Have you attempted to shoot two shots, one with HTP on and one off (both RAW, same ISO setting) and then open them both in Adobe to see the results? You can adjust the exposure the same amount in both and see if there is any difference in the highlight detail.

If you get an opportunity to do so, please post results!

*Bill wrote in post #4194427
I'm not a pixel peeper, and my images from my 30D and 40D are identical in print. I sold one of my 30D's to help fund the upgrade to a 40D. My desire to do so was based on the AF system of the 40D. IMO, it is FAR more accurate and consistent than that of the 2 30D's I own(ed). It always baffles me why people are constantly discussing IQ with every new camera that comes out, as if it is the only reason one should upgrade.

I understand your AF interest --- anyone who has owned a Rebel/Rebel XT and moved to a 20D/1D/5D should understand. The reviews show the one big improvement in the 40D AF is its functionality with lower contrast objects. That should be a huge plus to anyone relying on the AF! Very good point.

So...Phil say "ok"

That's a load off my mind. wait...I already got one.

*Bill wrote in post #4194427
I'm not a pixel peeper, and my images from my 30D and 40D are identical in print. I sold one of my 30D's to help fund the upgrade to a 40D. My desire to do so was based on the AF system of the 40D. IMO, it is FAR more accurate and consistent than that of the 2 30D's I own(ed). It always baffles me why people are constantly discussing IQ with every new camera that comes out, as if it is the only reason one should upgrade.

HERE HERE !!!!!!! The 40D is so much more fun for me than the 20D was.

Any guess as to when the 40D might break below the $1,000 mark?

As soon as 50D is released..

The 40D looks like a great camera, thanks for posting the review

Now for all those who bash and sing the praises of whatever camera it is. Fact is this, today you can buy just about any DSLR and get a great camera. The 20D is great, the MIII is great, the 5D is great, I even loved my 10D. Stop pixel peeping, get out there and enjoy these magnificent cameras. There is always something better if you are looking for it.

Hey,

I don't have the 40D yet -- I have a 30D and a 5D and too many lenses to count, so I'm not in a rush to buy anything just yet...

But what is HTP? It sounds like an in-camera setting that tells DPP to do some kind of post-processing. Is that what it is?

I shoot RAW and PP in Lightroom so it might mean nothing to me, but still enquiring minds want to know...

Tony

AngryCorgi wrote in post #4196441
Have you attempted to shoot two shots, one with HTP on and one off (both RAW, same ISO setting) and then open them both in Adobe to see the results? You can adjust the exposure the same amount in both and see if there is any difference in the highlight detail.

If you get an opportunity to do so, please post results!

Yes, I did both HTP and without HTP and examined in DPP and LR. That's how I saw that HTP makes a difference in Lightroom They were not fully controlled studio shots as they were taken a few seconds apart in late afternoon light (still clouds). Enough to satisfy me but I doubt they'd be enough to satisfy everyone - lol.

In the next couple of weeks I might get time to do some more controlled tests and will be happy to post the results. I'll be interested in following this up myself as I've only seen a couple of posted tests so far - one in DP review and one on the Bob Atkins site. It will be good to confirm one way or another.

AngryCorgi wrote in post #4196441
Have you attempted to shoot two shots, one with HTP on and one off (both RAW, same ISO setting) and then open them both in Adobe to see the results? You can adjust the exposure the same amount in both and see if there is any difference in the highlight detail.

If you get an opportunity to do so, please post results!

O.k., here is the requested demonstration:

Three photos of a step wedge shot at f/4 and 1/4, one at 200 ISO without HTP, the second at 200 with HTP and the third at 100 ISO without HTP, were opened in UFRaw. This Open Source free converter has the nice feature of showing a histogram of the RAW data - the only converter that I know of that does this since DPP's purported RAW histogram is in fact derived from processed data after picture style and white balance (and apparently HTP) have been applied. The first screen shot is of UFRaw. The upper histogram is input (RAW) and the lower one is RGB output. The first shot is fully exposed to the right. The second and third shots are identically one stop underexposed. Miriam, post 75, could have gotten the same results from LR merely by exposing one stop less.

Now lets see what DPP does. The RAW tab histogram is on the left, the output histogram is on the right. For the first shot the output is clipped (and so it appeared on the camera's LCD) although, as we have seen, it really isn't. Notice that for the second shot (the one with HTP) not only is the shape of the RAW tab histogram different, the margins have changed also. In terms of output the highlights of photo no. 2 fall between those of the other two while the shadows are like no. 1.

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Sounds good.