Hi Rich, My IQ is diminished because of noise and a lack of definition caused by too high ISO. Next show I'll be halfing my ISO and hopefully having greater latitude while editing my RAW'S. I have no control of lighting while shooting runway, perhaps shutter speed and aperture adjustments within reason will get me where I need to be. Thanks
That doesn't sound like it has that much to do with DR, to be honest.
A critical thing to recognize is that the added noise isn't coming from increasing the ISO, per se. The noise is likely to primarily stem from the light you're capturing (specifically how little of it you're capturing).
The biggest improvements will come from either opening up your aperture or increasing your shutter speed, as these get more light onto the sensor. (It's the greater exposure, not the lower ISO value that's the cause of low ISO images to look cleaner).
The DR chart helps point out that the lower ISO setting has wider DR. You could exploit this by:
Using your current exposure settings and reduce your ISO. This will give an underexposed JPEG but would also give you Raw files with roughly comparable levels of noise to your current shots, and with up to a stop of recoverable highlights.
But you're likely to get a much bigger improvement by pushing to see whether you have any scope for increasing your exposure (and using a lower ISO). This will improve the image noise across all of your image, not just the deep shadows that DR numbers describe.
Richard - DPreview.com
??? I'm shooting at 8000 9000 ISO at times it had everything to do with it. My fault!!! What a mess!!! My shots at 400 ISO had no noise, better contrast, color and a lot more latitude to edit my RAW's with my highlights, blacks and shadows. There was more latitude editing at the lower ISO. While not base, it was much better all around
While, generally speaking, there is a correlation between ISO and noise visibility in photos, the primary source of noise in that's visible in a photo is usually shot noise; noise that's determined by the total light used to make the photo. Whether we're working in a low light setting or using exposure settings (f-stop and shutter speed) that limit the amount of available light reaching the sensor, shot noise visibility increases as total light decreases.
Unfortunately, there's a long history of the mythical "exposure triangle" being used to teach photographers how f-stop, shutter speed and ISO combine to determine exposure. This fundamentally flawed model of image-making contends that increasing ISO increases some sort of electronic amplification of the image, adding noise to the image in the process. Nothing could be further from accurate.
Electronic noise generated by in-camera processing of is photo has historically gotten lower as ISO has increased. For this reason, it was a best practice when doing low light photography to get ISO as close to perfect as possible. If a high ISO was needed, use the highest ISO that would deliver an acceptably light image. In-camera processing at lower ISOs introduced more noise. Increasing the lightness of that image in post would reveal the electronic read noise already present in the photo.
Here's a chart from photonstophotos.net showing the "Shadown Improvement profiles of the Canon 1DX, 1DXII and 1DXIII:
courtesy: photonstophotos.net
Notice the slope of the lines. The 1DX slope is a gentle curve up to about ISO 3200 where it generally flattens. the 1DXII slope arcs up until flattening at about ISO 1600. The 1DXIII slope flattens at about ISO 800.
Where the slopes flatten and remain more-or-less constant are known as invariant ISO ranges. In other words, the amount of read noise introduced at those ISOs is the same. There's no reduction of electronic read noise to be gained by going to ISOs higher than about 800 in the 1DXIII.
Of course, there are other factors that influence a photographer's choice of ISO. Read noise is just one. For example, a photographer may prefer to use a higher ISO because it makes review and evaluation of the photo in the field much easier. Obviously, you know how to use your kit to make excellent photos. I'm not questioning that or the ISOs you choose to use.
The point of this post is to expand on Richard's earlier comments about the differences between shot noise and read noise as sources of noise in a photo. Yes, your photos made at ISO 8000+ are noisier than your photos made at ISO 400. But that's not because the higher ISO adds more noise. In fact, just the opposite is happening, especially with the Canon 1DX and 1DXII. It's the lower total amount of light used to make those high ISO photos that is the source of the more obvious noise in the photos. It's the shot noise that's the culprit.
Here's another chart from photonstophotos. This one plots the "Input-referred Read Noise" for the same three cameras:
courtesy: photonstophotos.net
Again, we can see the differences in the slopes of the three lines. The 1DX is more gradual until about ISO 3200; ISO 10000, if you want to be really strict about requiring flatness for an invariance range. The 1DXII starts to flatten by ISO 1600 and is fully invariant by ISO 5000. The 1DXIII is flattening by ISO 800 and becomes fully invariant at ISO 6400.
My question here was really, about noticeable IQ differences based on ISO and I can now see that I need to get down to at least half of what I'm shooting.
Certainly, there are benefits of increasing exposure and, by extension, the total light used to make a photo. Less visible (shot) noise and greater dynamic range are among them. That said, all three Canon 1DX bodies in your equipment list have 6-stops of dynamic range when an exposure that pairs well with ISO 6400 is delivered to the sensor. There are 5-stops of dynamic range at ISO 12800.
courtesy: photonstophotos.net
While the combination of ambient light, shutter speed to freeze movement and f-stop to deliver a satisfactory depth of field may call for a high ISO to produce a photo having a pleasing lightness, if the subject is evenly lit, 5 or 6 stops of dynamic range should be enough to capture detail in both the shadows and highlights. It is, after all, a relatively flat dynamic range scene.
Hard to experiment until you see how a room is hung but I'll be shooting at 2.8 or 3.5 vs. 4.5 and I'll be going to 1/500 or 1/250 vs. 1/800 based on the garments and cadence of the models.
4.5 at 1/800 was just overkill for DOF and shutter speed. First time using the Z9 for runway and it took one shoot to see where it shines vs. my 1DXMKII's and III's.
Still got the front cover and the back cover of the magazine... But there is much room for improvement. I thought the Z9 was a magic camera.... But like every other one... It does what you tell it! ROFL
Clearly, the editors choosing artwork for their publications are not put off by the images you're producing. However, photographers being their own harshest critics and whatnot, I understand your interest in pursuing improved image quality when shooting in low-light situations. The best pathway to that is, as Richard suggested, using shutter speeds a bit slower and lens apertures a bit wider...provided, of course, those choices don't introduce unwanted motion blur or result in lost details in the garments due to the shallower depth of field.
Best of success to you.
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Bill Ferris Photography
Flagstaff, AZ
http://www.billferris.photoshelter.com
