Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!
Here are examples of how the Quattro loses highlight detail in comparison with the Merrill
These image were taken with a DP2 Merrill and a DP2 Quattro repectively, both at 1/200 sec at F/8, ISO 100, which was 1 stop over the indicated exposure using the Merrill, but on 0.3 of a stop indicated with the Quattro. These are crops from a centre portion of the image.
The first example is from a DP2Merrill:
And here is a 200% enlargement, with some of the white wall roughtly burned in slightly to bring out detail.
Next are the equivalent image crops from the Quattro
You will see there is detail that can be recovered from the Merrill image, but much less from the white wall in the Quattro image (because the forum reduces the size of the 200% enlargements, you may need to open them in a new window to get the full effect).
Another factor I have noticed is that SPP 6.2.1 does not warn of the loss of highlight detail with the Quattro as accurately as with the Merrill.
I am prepared to accept that the colour balance and also the "naturalnesses" of the image, as well as detail, with the Quattro is marginally better than the Merrill when not being challenged by blown highlights. But this test was conducted at identical shutter, ISO and apertures so they should be broadly comparable.
Not in my opinion.Hi Quentin
Given that digital cameras are like positive rather than negative film when it comes to judging exposure and that the Q appears to have reduced dynamic range (similar to other AFE Sigmas like the SD15?), does this not call for better management of the highlights by the photographer ie underexpose a bit more?
I accept that this will mean reduced exposure and a little more noise in midtones and highlights compared to cameras with more dynamic range but the DR of the sensor is what it is. It'll also need other DR management techniques such as grads, HDR techniques, fill flash, reflectors etc, just like the good old days of slide film.
Or is there something else going on a bit more weird with this highlight blow out problem that is more complex than restricted DR?
A fine image Quentin, I can assure you today in Mevagissey was rather dull and grey but the past week has been shorts if not tee shirts and a taste of summer, very welcoming.When I use a Quattro, I can see the potential. There is more real resolution, and the colours are better, but the clipping issue then make the camera unusable in many situations. The Merrill is a better bet.
Not much cooking today, I'd be better off in Mevagissey! But at least the sun is out (DP2M)..
Edit: of course, Sigma's excellent implementation of auto bracketing will help the Quattros in tripod-based situations
Not in my opinion.
The problem is the inelegant way the Quattros' clip. Its sudden and to some extent, unpredictable, and very non-film like.
Certainly filters will help, as will the very neat way Sigma have applied automatic bracketing. But the problem is noise. Underexpose a Quattro and you are in for a rough time.
If you use a Quattro, then you simply must be very careful about anything approaching a possible highlight blow out.
I'm going to give you an example of a shot I took on Morocco in late 2012 with the DP2M that would have been ruined and useless had I take the same shot with a Quattro today.
The woman's face was overxposed, as was the background, but the latitude of the Merrill sensor enabled me to recover it (it was a very high contrast midday sun image).
It's with situations like this that filters are useless. Yes, I could have reduced the exposure, but I might have missed the moment or had too much noise in the underexposed shadow areas.
Im angry, David. I'm bloody angry! the Quattro has potential but it needs development.