Upgrade Planning

[Andrew76]

I'd seriously consider flash. I don't want to re-hash the numerous times that continuous lighting has been bashed, and totally trashed here on this forum, but if you plan on getting into some studio, or portraiture type work, the continuous lights you have won't be of any use - a flash, or even studio strobes would be my next bet.

Just to clarify, for still life's like you've got here, the continuous lights are fine, although it'll take you some pp work to fix the backdrop, etc. But for people, or anything that moves, you'll struggle with them.

[proseak]

Kyle, are you shooting Jpeg, or raw?

[William W]

DX versus FX format. What is the difference?

The differences for me are (nothing to do with noise) - but as a general answer:

1. Shallower DoF possible for any particular Framing - not used by me all the time but when it is used there is an astounding difference.

2. The Very Fast Wide Angle lenses which are available (not available 'equivalent' for APS-C) - this is really important for me. I do use the Wide Angle FoV often and I shoot a lot of Available Light Portraiture, so to have available a 24/1.4 (and 35/1.4 and 16 to 35/2.8) is important and these lenses are used often by me.

3. Ability to use the full range of T&S Lenses at the FoV/FL for which they were designed - Again not as much as an everyday importance as item #2, but it is important, especially considering that I do use the TS-E 90mm for Portraiture and one cannot get an "equivalent" lens for that, using and APS-C camera.

4. Ability to use the most superior lenses at the FoV/FL for which they were intended - this is more 'passion' than practical, but there is some practical value in this comment: for example (in Canon) the ability to use the:EF 200/1.8; EF135/2; the EF35/1.4; the EF70 to 200/2.8; the EF400/2.8 and the TS-E 90/ . . . in Nikon I immediately think of the 105mm . . . and etc.



WW

[ajohnw]

Looking at this review of the d3100 you should be able to use it up to at least 800 iso I would have thought fairly easily. Even higher,

http://www.dpreview.com/reviews/nikond3100/10

Noise isn't something that I haven't had to cope with but if evident and attempts are made to process it out I would suspect that's best done full sized before reduction. You will probably find the usual reductions to web sizes alone also reduces it by a fair amount.

As cheat and under unfavourable conditions I have been known to set full auto and providing the aperture is suitable let the camera do it's own thing for a jpg. It can be really surprising what a camera can do like this sometimes as the manufacturers spend a lot of time and effort in this area. Often it finishes up with something that needs a minimal amount of work for web sized shots or even small prints.

You might like to take some mixed colour shots at 200,400,800,1000 and 1600 iso always with the correct exposure. And compare shots with the review. Noise reduction on. Personally I feel it's best to know your own camera. Then reduce and process shots as you intend to do. This will give you some idea what the camera can achieve which always helps. Personally I reckon it takes a couple of hundred mixed shots before anyone can even be sure what the camera will do with them.

Interesting comment from Andrew - expense no object great because for set up the best bet is flash heads complete with modelling lights. Floods of one sort or another work out cheaper and can still produce double nose shadows and poorly lit backgrounds as can the flash heads. Learning is the difficult bit. And don't I know it - have had access to both.

John
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[Colin Southern]

I think ISO noise creates more confusion among photographers than just about any other part.

Just to cover some of the technicalities:

- Every sensor has a saturation point -- the point at which additional photons hitting the sensor don't increase the charge because "the buckets are all full".

- Every sensor has a noise floor - the point where desired signal is so low it's indistinguishable from the background noise

At base ISO (typically 100 for Canon and 200 for Nikon) the difference between these two points defines the dynamic range of the sensor, and with a modern DSLR camera is typically in the region of 12 stops (which - for a RAW capture is usually more than we need assuming a good exposure because prints can only reproduce around 4 stops, and monitors can only display around 6 stops -- so the camera is typically by far the STRONGEST link in the chain) (but I digress).

At ISO settings higher than base ISO the physical characteristics of the sensor don't change, so what happens is less and less of the sensors natural dynamic range capability is used and the signal obtained is amplified to the same level that we would have got had we used base ISO; the only difference is that the noise floor is also amplified. If base ISO is 100 and you shoot at ISO 200 then you're effectively only using the "bottom 1/2" of the sensor (and dynamic range is reduced by 1 stop). At ISO 400 you're only using 1/4 of the sensor and DR is reduced by 2 stops -- both are pretty much "who cares" at that stage because you're still capturing around 10 stops and most reflective scenes don't need more than 4 (ish).

But as the ISO level continues to climb, the available dynamic range continues to drop - and the photographer ends up operating closer and closer to the noise floor; at this point noise may or may not start to become visible. At base ISO there is a LOT of safety margin inherently built in, but as the ISO climbs, the photographer needs to be far more precise in their exposures, and for scenes with a high dynamic range, he may well have to start sacrificing highlights or the quality of shadow areas to get the shot (or use other techniques like bracketing).

What many photographers don't realize is that when the camera chooses the exposure, unless any EC (Exposure Compensation) is applied then it'll normally set the middle gray point (which all camera metering uses as the basis of the exposure) around 4 stops down from what it thinks is the sensor maximum for that ISO - and that means that a reflected highlight is around 2 stops down from this "maximum" - thus allowing around a 2 stop "safety margin" to cater for any degree of backlighting / incident light. At base ISO that's not a problem, but at higher ISO settings it's a safety margin that we often can't afford as a 2-stop safety margin means that everything is shifted 2 stops down towards the noise floor -- and when that signal is normalised in post-processing the noise floor is amplified also, giving us visible noise. (in that context the camera doesn't really create visible noise at any ISO -- it's really us photographers REVEALING the noise when we normalise a high-ISO shot to remove the safety margin).

So - to translate all of this into "real-world English"; If a photographer has a noise problem at high ISOs then it's due to one of 3 things:

1. The exposure has too much safety margin, and needs to be increased so that more signal is captured to get further away from the static noise floor (ETTR or "Expose to the Right" in this case).

2. The dynamic range of the scene is too great to be captured at that ISO (eg a scene with a 12 stop dynamic range isn't going to "fit on a sensor" with only 8 stops of effective dynamic range left due to the fact that it's operating at ISO 1600.

3. They're obsessing over the levels by looking at the image at 100% magnification (the image below is a good example; at 100% magnification the noise is quite significant -- but "who cares"; the image at normal sizes looks OK).



In real world terms - usually - the problem is due to either not pushing the exposure a stop or two at the time of capture, or a scene with a high dynamic range (eg a night scene like mine, or a poorly lit subject where the photographer is trying to dig detail out of the shadows rather than use a fill light).

Changed technique helps with both situations, along with quality lighting where possible. Camera selection for a given genre of camera usually makes very little difference (eg a new DSLR over an old DSLR), however moving from, say, a a camera phone or point & shoot to a DSLR is likely to make a big difference.

Hope this helps.

PS: All of the above applies to RAW captures; if you're shooting JPEG - at high ISO - and (essentially) under-exposing (as I suspect you might be, as you mentioned that you have in-camera NR turned on - and in-camera NR ONLY has an effect on JPEG shots) then the issues will be an order of magnitude higher because JPEGs throw away LOT of info - info that's needed to correct the shot if the exposure isn't very close to optimum at the time of capture (within a stop or so).

[proseak]

Colin, you write "as you mentioned that you have in-camera NR turned on - and in-camera NR ONLY has an effect on JPEG shots)" but maker's own raw conversion may well honour these settings, whereas ACR or DxO won't.

So, if part of the problem is Nikon's interpretation of the raw files, and Kyle has kept them, reworking in a real processor like ACR might help quite a lot.

HTH

Peter

[Colin Southern]

Colin, you write "as you mentioned that you have in-camera NR turned on - and in-camera NR ONLY has an effect on JPEG shots)" but maker's own raw conversion may well honour these settings, whereas ACR or DxO won't.

Yep, for sure - but 9 times out of 10 people don't realise that and either shoot JPEG or think that NR is applied to RAWs in-camera. Not many seem to use manufacturers software for RAW conversion.

So, if part of the problem is Nikon's interpretation of the raw files, and Kyle has kept them, reworking in a real processor like ACR might help quite a lot.

I agree, but somehow I think they're coming for us Peter ... I can hear the war drums in the distance ... and they're getting closer ...

[revi]

For me, the first image looks a tad over-exposed (not too surprising, given the amount of black in the image)
The three others all look (too) dark to me: the white sheet is gray...
Don't forget that 1/40 @ 400 ISO corresponds to 1/10 @ 100 ISO, and you used 1/30 @ 100, and 1/100 @ 400 (with a slightly smaller diaphragm at that). So it's normal that your images are a lot darker.

The shorter exposure does give you more visible detail in the sheet, and deeper colours on the bear. But if you ever need to brighten the image, you get (a lot of) noise in the shadows.

Another way to perhaps get a bit more out of your images is to start using RAW (although when you start with that, the results might be disappointing at first), or play with the in-camera jpeg settings (contrast, saturation, sharpening, ...). The latter only influence the in-camera jpeg (and the raw preview image).
That's not to say that RAW is always the best format to use: it does require more time to get an image to show, and not all situations require the extra leeway RAW can give you.

[AB26]

Hi Kyle,

When shooting in conditions with low dynamic range you will notice less noise. The more evenly a scene is lit the higher ISO settings you can use.

Get your framing closer to what you want the image to look like and avoid cropping as much as you can.
Off cause, the beter the light you are shooting in, the less the noise will be when keeping ISO settings as low as possible.

[Analog]

I'd seriously consider flash. I don't want to re-hash the numerous times that continuous lighting has been bashed, and totally trashed here on this forum, but if you plan on getting into some studio, or portraiture type work, the continuous lights you have won't be of any use - a flash, or even studio strobes would be my next bet.

In this particular case I choose the continuous lighting over flash as I felt it would be more consistent between shots. I'll do a few test shots with flash and post them to see what my results are.

Kyle, are you shooting Jpeg, or raw?

Both at the moment. Photos posted earlier were the Jpeg produce by the camera.

So, if part of the problem is Nikon's interpretation of the raw files, and Kyle has kept them, reworking in a real processor like ACR might help quite a lot.

I do still have both the raw files and jpg files produced by the camera.

Get your framing closer to what you want the image to look like and avoid cropping as much as you can. Off cause, the beter the light you are shooting in, the less the noise will be when keeping ISO settings as low as possible.

Will keep framing in mind more during the next round of shots.

[RustBeltRaw]

I'd echo Colin's assertion that noise is essentially irrelevant much of the time. I live above ISO1600 (low-light action) with a crop-sensor camera, and as long as the noise isn't destroying details in your subject, why worry?

Perception of noise is also a critical question. For instance, if you were shooting a high-key subject (mostly bright), you could get away with a high ISO, since the pixels (photosites) relevant to the subject will have a high signal-to-noise ratio (SNR). High ISOs multiply that SNR, so if you expose the subject to the right, they'll have a good SNR and much lower perceived noise. Note that no sensor characteristics have changed here - you're just giving the sensor the best chance to produce a clean image.

In a low-key scene, where you decide to make your subject deliberately dark, you may be in trouble. Then you need to stick with low ISOs to avoid having too much noise in your subject. Same reasons as above.

[Analog]

Did some more shooting with my test subject this time using a flash. This was shot with the 55-200mm kit lens at 66mm F5 1/100 ISO800.

Full size: http://backup.cambridgeincolour.com/...C/DSC_3098.JPG

[Manfred M]

In this particular case I choose the continuous lighting over flash as I felt it would be more consistent between shots. I'll do a few test shots with flash and post them to see what my results are.

Continuous light is okay if you are shooting a stationary subject, where you can choose an appropriate ISO and shutter speed and use a tripod, but it is generally not great for anything involving a subject that moves.

Flash, whether is is a small flash or studio light put out a short, high intensity bust of light that lasts a very short time (in the order of 1/1000th of a second). Speedlights (depending on the model) tend to have light outputs in the 50W-s to 75-W-s range, while studio lights are in the 400W-s range (and can go much higher).

Let's do a bit of math; assuming that 1/60th second, hand held shot is as slow as you want to go and you are lighting your subject with two 100W incandescent lights (200W total). 200W x 1/60 sec = 3W-s. That's not a lot of light, in fact it is an order of magnitude (10x) less than a small flash and two orders of magnitude (100x) less light than a studio light. So to compensate you have to crank up your ISO, shoot wide open, shoot at a slow shutter speed, etc.

Back in the old film days, when ISO 400 was really as fast as you wanted to go without getting too grainy a shot, the only alternative was to "add light". Today, we tend to try to crank up the ISO, but it has unintended consequences as well, when going to flash is probably a better solution.

By the way, one advantage studio lights have over small flash is that they have built-in modeling lights, so you can get a pretty good view of how the light is going to affect your subject without doing a test shot (shadows and lighting ratios).