View Full Version : High ISO / Noise question

18th March 2011, 10:53 AM
Hello all

I've a question that's grown from a comment made by Zuiko on one of my photos

The comment was "When you get the E-5, you should be able to shoot at ISO 1000 or even 1600. Even with the 620 I think you would find less noise in a brighter exposure at a higher ISO than 320. In a similar situation try ISO 800 but without the -1 stop compensation."

My question is, "I've always been wary of higher ISOs because of a lack of understanding regarding noise control and detail retention...

With my E-5's imminent arrival, would you say that the best results would be found in RAW files post processed for noise/sharpness (in which case, what would be the best software to use to control noise whilst retaining detail), or in camera JPEGs with the camera processor doing the work?"

Thanks guys

Bikie John
18th March 2011, 11:37 AM
I'm still getting used to the E-5 but as far as I can see the in-camera JPEG processor does a pretty spiffing job with noise. However, there may be times you need raw (*) for some other reason (funny lighting, very high dynamic range). Oly Master, which I don't find easy to use, seems to process noise quite well by default. Adobe Camera Raw (for which you need a pretty up-to-date version for the E-5) does not do anything with noice unless you tell it to - but when you do its noise reduction also works very well.

I think it was in Ian's early tests that he said that E-5 high ISO noise is there, but it is very amenable to processing without too much loss of detail.

Ciao ... John

<Hobbyhorse alert> It's not RAW, it's raw. It's a word, not an acronym, and unlike so many technical words it means almost exactly what it says </hobbyhorse>

18th March 2011, 12:53 PM
Yes, there is noise and there is noise. If you are shooting in JPEG and switch the noise filter off or set it to low instead of standard, you will see a graininess in your images even at minimum ISO. This can be filtered out very easily. I do recommende RAW. Here is a shot taken on an E-PL2 that I took this morning at ISO 800 (1/6th second but I forgot to turn the IS on):

http://dpnow.com/galleries/data/547/P3185220.JPG (http://dpnow.com/galleries/showphoto.php/photo/23607)

This is from a RAW file. You can't see any noise because it's been filtered out in Lightroom 3.4 RC. But it's not always a good idea to eliminate all noise, even at low ISO as the noise can form part of the desirable 'structure' of your image detail. Indeed, it's a technique that professional photographers sometimes use to add noise to an image if it's a bit flat.


PS That's my daughter ready for school dressed to look like a 'nerd' for Red Nose Day!

18th March 2011, 02:15 PM
Love that photo !!!

So raw is probably the best approach...with a useable range up to 3200 (1600 preferred) ?

18th March 2011, 02:55 PM
Love that photo !!!

So raw is probably the best approach...with a useable range up to 3200 (1600 preferred) ?

Best experiment yourself - what RAW conversions software do you use?

I have certainly had acceptable results at ISO 3200 with the Pens and the E-5. ISO 6400 sees a steep drop in quality, but can be OK for some types of picture.


18th March 2011, 06:17 PM
Best experiment yourself - what RAW conversions software do you use?

I have certainly had acceptable results at ISO 3200 with the Pens and the E-5. ISO 6400 sees a steep drop in quality, but can be OK for some types of picture.


I agree with Ian, the picture that you are taking will determine the ISO setting that is usable.
When I first got my E5 I experimented with different lenses/settings etc. The images in my gallery here (http://www.imageinuk.com/Test-Images/E5-at-ISO-6400-Molly-at-121/15252823_HBW9z#1141148488_Za9EG) were taken at ISO 6400.
As a rule though, I try and keep to ISO 200 for wildlife shots and only increase the ISO to keep the shutter speed up. I will go up to ISO 1600 for wildlife, anything higher will just be a record shot.
As far as noise is concerned, this is easily dealt with but at the expense of detail loss which you would expect. This seems not to be as big an issue as it was with my E3/E500 though.

Regarding RAW, I again agree with Ian that this is the best method of recording images. At least you have all the image data to use in PP and not just the reduced amount resulting from recording jpg files. Having said that, the jpg output from the E5 is very good.

18th March 2011, 09:27 PM
The basis of my comment is that it is better to use a higher ISO to perfectly expose the shutter speed/aperture combination you need rather than underexpose in order to use a lower ISO. In my experience when pushing the limits trying to lift an underexposed image in pp will induce more noise than if you shot a stop higher ISO, exposing to the right of the histogram for a better exposure.

However, at higher ISO values there will always be a trade-off between noise reduction and detail. Even with crop sensor Nikons and Canons this is still an issue, maybe not quite so much as with Olympus but the gap is not as great as we're often led to believe.

The type of noise is another factor. We definitely do not want chroma noise or banding, but a little luminance noise can actually help create a very film like effect. Good 3rd party programs such as Dfine, Noise Ninja and Neat Image do a remarkable job of cleaning noise from an image whilst preserving most of the detail.

The ultimate effect of noise very much depends on how big you print. It might be unnacceptible at 16x12 but hardly noticable at 10x8 or A4. Sometimes on Internet forums I think we can get a little too theoretical, searching for signs of noise at 100% etc.

I'm sure if we'd had forums in film days we'd have been debating exactly the same type of thing. I can just imagine: "Velvia 50 may have a granularity of RMS 9, the same as Kodachrome 25, but Kodachrome grain is more evenly patterned and less inclined to clump." "Ah, yes, but don't forget Velvia is a stop faster." "That's questionable, many people consider Velvia is more of a true ISO 40 or even 32." And so it would go.

In practice, of course, the grain of slow films like that was barely noticable, let alone distinguishable. And yes, if you looked close you could see a little more grain in an RMS 10 film like Kodachrome 64 but very few people worried about it. Much more relevant was whether you prefered the colour palate of Fuji or Kodachrome. Strangely, today we tend to pay little attention to the colour characteristics of different digital cameras. I've always particularly liked Olympus colours, but I digress.

In those days some photographers purposely sought out grainy films, particularly B&W, for the mood and atmosphere it created. "Pushing" the film (the equivalent of raising digital ISO values above the native sensitivity of the sensor) was a popular way of increasing the grain even if the extra speed wasn't really needed. And some of the older one's here will remeber GAF 500, a film prized for it's "grain like golf balls."

In short, I think that with an E-5 (provided you expose properly) for practical purposes noise won't be an issue. :)

21st March 2011, 11:13 AM
Thanks john. I'm HOPING I'll be out with the E5 this weekend - I'll make a point of pushing the ISO, just to compare with previous results.

by the way - I love your work.