Question for our Hy6/sinarback owners

[Stuart Richardson]

I have been shooting with the 54LV for a little bit now, and one thing is very clear: AE mode gives me consistently underexposed photos. I generally convert the files to DNG in eXposure, and then edit them in lightroom 2.0. In almost every photo, I have to bring the exposure up 1 to 1.5 stops. The files handle this extremely well, but it does give some color and luminance noise in the deep shadows. And if this is the "natural" state of these files, it would mean the real ISO of the back is 25 (or even ISO 18.75, which is 1.5 stops slower).

I am wondering if this is an aspect of the back, the camera, some sort of miscommunication between the back and the camera, or what have you. The camera seems to expose properly for film, though I have only shot negative film so far, so the latitude might be covering any errors.

If other users do experience this, is there a way to deal with it other than simply using exposure compensation?

 

[EH21]

Stuart,
I don't have a 54LV but have noticed and also read some posts about Lightroom setting the exposure values down and this is certainly true with my Phase p20 files. It reads as one stop lower than in C1.
Eric

 

[Guy Mancuso]

Same here with my P25 plus files at least a stop under in LR. Best advice for LR is make a preset than when you import the images you can tag the preset on import so at least the exposure is coming in normal. Also i have noticed the color temp is in another light year coming in around 2800 for daylight. For me this is a real pain because many times i will WB to a certain color temp that I know is correct or what value i like in certain lighting conditions. Since owning the Phase back i went back to C1 which for Phase files is dead on the money plus has corrections for my glass.

Your exposures are correct Stuart it is the software profiles for Phase and apparently Sinar that are off in LR. So it is NOT you or the camera but the program

 

[Stuart Richardson]

Great, thank you both. I will explore a preset and also try to see if Capture one is any better. For what it's worth though, they seem to be underexposed in eXposure and on the back as well (or at least the histogram seems to be weighted heavily to the left).

 

[Graham Mitchell]

The histogram on the back should clear up any exposure ambiguity.

edit: you beat me to it

 

[woodyspedden]

Great, thank you both. I will explore a preset and also try to see if Capture one is any better. For what it's worth though, they seem to be underexposed in eXposure and on the back as well (or at least the histogram seems to be weighted heavily to the left).

Stuart

I have been doing product shots for my daughter's web based business and I noticed the same thing in Lightroom. (Nikon D300) From the camera histogram I know I am almost spot on.(Exposed a bit to the right). The minute I go to ACR in Lightroom 2 it resets the exposure to -1.5 stops? So it is not just a Phase profile issue........it is an issue with NEF as well. Lightroom cannot open the Hassy 3frr files so I don't know what would happen there.

Woody

 

[Stuart Richardson]

Ok, I better provide some examples. Here are a few photos, along with what the histograms look like on the back. I am including both the straight, unedited photos from Lightroom, as well as the reworked photos. These are not really tricky lighting situations, so the metering should be spot on. It is on multi-segment metering on the Hy6.
Graham, if you in particular could address this, I would appreciate it as I know that you have the same back.
The first one is more or less correct on the back, perhaps a bit to the left, but comes in to lightroom a stop dark.

Uned:

Quickly brought up to what looks right to me (+1 stop exposure in lightroom):

The next one is more underexposed -- this was a pretty flat lighting situation with neutral tones, AE should get this fine:

That definitely looks pushed to the left to me.
Here is the unedited copy in lightroom:

And brought up to normal (+1.50 stops exposure in lightroom):

 

[Stuart Richardson]

To be clear, most of the photos have histograms bearing more resemblence to the second photo than to the first. I have to assume this is a metering or back issue I guess. Do those histograms look standard to you Graham (or David, or Thierry?)

 

[Stuart Richardson]

No great claims on the photos either...I was just walking around taking snapshots to get more familiar with the back...

 

[Guy Mancuso]

Stuart as I said your on the money even with the one that looks under in Histo . Dark all around subject anyway. It is certainly LR to me. First one is dead nuts on the money.

Stuart and everyone else at some point you have to say screw all the technology and just go by what is right in your head. None of this stuff can think, it is only data points that we as the artist can go by but toss away if it is not what your vision is or what you think it should be. ONLY you can think logically.

 

[Graham Mitchell]

I'll have to do a test tomorrow with LR. It's pitch black outside now. Also I don't have a P&S to take a photo of the histogram but I'll see what I can do.

 

[EH21]

Stuart that's interesting - certainly the portrait of the man is underexposed (even though it came up nicely). How do you have the metering set on your Hy6? I don't have your set up but on my 6008/p20 the back and camera are not communicating ISO values so if the back is at ISO 50 I have to set a +1ev to the camera, ISO 200 on back means -1ev on the camera, etc. I see you have your back set to ISO 50...could this be what's happening for some reason?
Eric

 

[Stuart Richardson]

Thanks for helping out guys. I think in the mean time, I am just going to have the back do a +.7 EV correction. That should give me a bit better shadow detail without clipping too many highlights. That and trust less in the AE...

Eric -- that is a very good suggestion, but I was pretty sure that the back automatically communicated the ISO to the Hy6 -- I checked it out, and the back's set ISO instantly is transferred to the Hy6 -- no photographer "interference" needed...or possible actually. Adjustments have to be made in EV, rather than ISO settings.

 

[Stuart Richardson]

By the way, I opened up the images in Capture One and they look better than in lightroom, but about the same as in eXposure. They are all still a bit underexposed. They look a bit better than eXposure, but that is because Capture One automatically applies a curve, sharpening and so on...eXposure leaves everything alone (which I prefer). For whatever reason, lightroom is about a stop under. Very odd. Some are still a bit underexposed, but they seem much more accurately exposed.

 

[EH21]

Not that this is helping much, but I have found that I tend to prefer the look of images shot under that are pushed up in the RAW converter than images that are shot ETTR and pushed down. This is not necessarily true with my Canons but is true with my leica DMR and the phase back possibly because of the extra dynamic range. I started a very long thread close to a year ago on LL forums about it and to make a long story short quite a few MFDB users agreed. If you are using ETTR then you need to use a linear curve and do your exposure adjustments then make a custom curve because the RAW software is designed to work with exposures at nominal values not ETTR. This was confirmed by one of the software engineers on a companion thread on the Open Photography forum. So it might just be that the camera is designed to shoot where it does. Certainly your images posted here look fine after adjustment.

Try it for your self. Shoot manual exposure for ETTR then push down exposure to correct values and set shadow points. Do the opposite and expose properly for the shot or even under and adjust for exposure and shadow points in RAW. Which one do you like better? Okay now take the ETTR shot, set the RAW curve to linear and try to make your own curve to get the image to look better than the properly exposed or even under exposed image. While it may be you'll get better data, I think it takes a lot of work and that custom curve isn't going to work for every image you shoot - or at least that's what I found. So its hard to make a preset to handle the files. All this plus the digital fact that blown highlights are lost and gone forever is probably why the camera makers are setting exposure metering a bit low.

 

[woodyspedden]

Thanks for helping out guys. I think in the mean time, I am just going to have the back do a +.7 EV correction. That should give me a bit better shadow detail without clipping too many highlights. That and trust less in the AE...

Eric -- that is a very good suggestion, but I was pretty sure that the back automatically communicated the ISO to the Hy6 -- I checked it out, and the back's set ISO instantly is transferred to the Hy6 -- no photographer "interference" needed...or possible actually. Adjustments have to be made in EV, rather than ISO settings.

Stuart

To avoid confusion you may want to shoot for the proper exposure using the camera's histogram and then build a preset for Lightroom adjusting the exposure to your liking.

Woody

 

[thsinar]

hi Stuart,

First, LR does effectively open the images darker: I can confirm this

But then, if your histogram is to the left (in AE mode), it necessarily indicates an under-exposure, wherever this comes from: the light-meter setting, the light condition (rather not, since you have it with different situations), etc ...

You said that you have set AE to "multi-segment metering": did you try another mode and have the same?

Then, concerning eXposure and ISO in general: the ISO definition has no standard in digital. It HIGHLY depends (but not only) on the curve used AND on the Gamma value of the "working space".

- in sRGB, a medium (18%) grey should give 119/119/119 RGB, with ECI set it should give 101/101/101. Thus, a medium 18% grey is not necessarily 128/128/128 and not necessarily centered in the histogram.

What you can try:

- shoot a white piece of paper evenly lit, with AE: it should come medium grey (18%): respectively, if you measure then the grey, it should be indicating RGB values close to the above numbers, depending on the working space used. Use for this "Standard Curve 3" in eXposure.

I hope this can give a first clue if something is wrong.

Best regards,
Thierry

 

[Stuart Richardson]

Thanks Thierry, I will give that a try. I have only been using multi-segment. I may switch to center weighted or spot, as it is more certain just what is being used to meter. As I said, I am still learning this system, so I don't want to lay blame on anything other than my experience yet.

Also, I know what you mean about the profiling issue. When I brought the images into capture one, there was an option to choose "Adobe DNG Neutral" as a profile, and when I did so, the images brightened up noticeably.

 

[Samuel Axelsson]

Stuart,
I don't have a 54LV but have noticed and also read some posts about Lightroom setting the exposure values down and this is certainly true with my Phase p20 files. It reads as one stop lower than in C1.
Eric

Same experience here.

 

[BradleyGibson]

Stuart,

FYI, for me, the same .IA+.BR+.WR files, a run through Brumbaer Tools gives me a dng which is about a stop brighter than the dng the same source files yield via eXposure (as developed in Lightroom). Between Brumbaer and eXposure, I'm not sure who's right, but it would be interesting to see if Brumbaer Tools gives you the exposure you were expecting.

Even after a rough attempt to calibrate the colors from Brumbaer, I find that Sinar eXposure gives superior color (particularly in the yellows and greens), so until I get my hands on a Minolta color meter and can really calibrate Brumbaer with precision, I'll keep using the darker .DNGs from eXposure.

Of course, your mileage may vary...

Take care,
Brad