Tag Archives: ISO

Experimenting with PureRAW3

This blog includes a very infrequent series of posts reviewing the processing powers of PureRAW.  The third version of this raw image processor has just been released and I downloaded the trial to see how it performs.  I was impressed by what the previous version did to clean up some high ISO shots but the need was limited and the price was high enough that I didn’t see the point in signing up for it.  I was curious as to whether the third version would change my mind.

When I download one of these trials, I always try to avoid installing it until I have time to play with it.  The trial last 30 days so I want to make sure I make good use of the time.  Once I got around to installing it, I put it to work.  I was disappointed to find the trial was limited to 20 images at a time which is a little restrictive but, for the purposes of evaluating it, I could work around this.  I had two things I wanted to do.  First, I wanted to convert some shots that I had previously tried for PureRAW2 to see how different they were.  Second, I had some recent night shots which I also wanted to try.

So, how did it perform?  Results were mixed.  I found the conversion process was quick sometimes and would slow down or stop on others.  This was annoying but I suspect is something that they will fix before too long so I wasn’t that worried.  What I was surprised about was that, when starting the process in Lightroom, the new DNGs will be reimported into Lightroom.  However, this was unbelievably slow.  I would set it off, the conversion would finish and then, a long time later, they would suddenly get added.  Again, something that is probably going to get fixed but bloody annoying in the mean time.

As for the output, I was quite amazed by the results.  I will show here some of the Lightroom edits along with PureRAW2 and PureRAW3 versions of the files.  As you can see, the latest version really does clean up images a lot.  However, I don’t think it is all good.  Some of the shots feel like they have been over sharpened and look too crunchy.  Also, the algorithm seems to get imaginative when it comes to lettering on airframes.  Some of the results have created shapes that just are not there in the original shot.  For some shots, this might not be an issue but, when something is supposed to be recognizable, the odd artifacts show up conspicuously.  If the shot had been soft and noisy, you wouldn’t have worried but, because it is supposed to be clear and sharp, the weird results stand out.

Is it worth it?  Not for me.  I used it on some more normal exposures and couldn’t really see much benefit.  Certainly not enough to make the effort worth it.  For high noise, it does provide some nice results and some odd side effects but, I don’t shoot enough of them to make that really worthwhile.  For now, it shall sit in the interesting but not interesting enough category.  Maybe we shall have the fourth installment of this series when PureRAW4 comes out!

High ISO Shooting and Processing Technique

I watched a video on YouTube about a way to process shots taken in low light with high ISOs to improve the noise performance.  I wasn’t particularly interested in the approach until I was down on the shore as the sun was going down and I was using a long lens.  I figured this might be a good time to try it out.  The approach is to shoot a lot of shots.  You can’t have anything moving in the shots for this to work but, if it is a static scene, the approach can be used.

Shoot as many shots as you can.  Then import them in to Photoshop as layers.  Use the align function to make sure that they are all perfectly aligned and then use the statistics function to do a mean calculation of the image.  You can do this a couple of ways in Photoshop.  You can make a smart object and then process it or you can process through Statistics.  The averaging function takes a lot of the noise out of the shot.  If you have lots of images, you can make it effectively disappear.  I wasn’t prepared to make that many shots but I tried it with a reasonable number of images.  The whole image isn’t really of interest.  Instead, I include one of the images cropped in and the processed image similarly cropped to allow you to compare.

Making Use of the Camera’s Features

One of the things that I was glad to get when I last changed camera bodies was the ability to have exposure compensation while shooting in manual mode.  You might wonder why this is a useful thing to have but I was shooting a couple of time recently when it was useful.  Sadly, the first time I didn’t think to use it.  The second I did though.  This is the result of shooting in dark conditions when the light levels are changing quite a bit.

The problem in the first case was that I was shooting in aperture priority mode.  The light was low, so I went to auto ISO to allow it to adjust.  The camera looks to get a shutter speed that is related to the focal length of the lens you are using.  I was shooting a landing aircraft and, when I was out at the full length of the zoom, it kept shutter reasonably high.  However, as the plane got closer and I zoomed out, the camera dropped the shutter speed down which meant the panning resulted in a lower keeper rate.  I should have foreseen this and I was annoyed with myself.

The next time, I thought through the issue a bit better.  A gray sky meant that I needed to have some positive exposure compensation.  I went to manual mode, set the shutter speed and aperture that I wanted but included the exposure compensation.  Then I set auto ISO.  Now I had the ISO adjusting to get the combination I wanted while including exposure comp.  On my old bodies, this was not possible.  The result was the exposure I wanted with ISO adjusting throughout the sequence.  When conditions are not great and changing quickly, this is an approach I can highly recommend.

Blue Angels at Oceana (And High ISO)

I have only been to the Oceana show once.  I headed down there with my friends Ben and Simon.  We weren’t terribly lucky with the weather.  There was flying during the show but things were overcast and deteriorated as the show went on.  The finale of the show was, naturally for a big Navy base, the Blue Angels.  I was shooting with a 1D Mk IIN in those days and that was a camera that was not happy at high ISO settings.

The problem was, the light was not good and the ISO needed to be cranked up a bit.  Amusingly, if you were shooting today, the ISO levels would not be anything that caused concern.  Current cameras can shoot at ISO levels without any noise levels that would have been unthinkable back then.  However, I did learn something very important with this shoot.  The shot above is one that I got as one of the solo jets got airborne.  I used it as a test for processing.

I processed two versions of the image, one with a lot of noise reduction dialed in and one with everything zeroed out.  I think combined them in one Photoshop image and used a layer mask to show one version in one half of the image and the other for the second half.  When I viewed the final image on the screen, the noise in one half was awfully apparent.  It was a clear problem.  However, I then printed the image.  When I did so, things were very different.  If you looked closely, you could see a little difference.  However, when you looked from normal viewing distances, there was no obvious difference between the two.

My takeaway from this is that viewing images on screens has really affected our approach to images.  We get very fixated on the finest detail while the image as a whole is something we forget.  We print less and less these days and the screen is a harsh tool for viewing.

How Low Can You Go?

The high ISO capabilities of modern cameras are a constant source of discussion whenever a new camera comes out.  It was quite funny to see everyone get so excited about the multi-million ISO range on the Nikon D5 when it was announced, only to see that the high ranges were nothing more than moose with a bit of an image overlaid on them.  Not a big surprise but still funny to see how much everyone was going nuts about it before the reality set in.

Consequently, I was interested to see what the new bodies I bought were really capable of.  I have already posted a little about some of the shots I took as the light faded at SFO.  I was shooting with a tripod and a gimbal mount to make things easier but I was also working within the ISO range of the camera.  I went with auto ISO and exposure compensation while shooting in aperture priory and wide open to get what I could.  However, I really wanted to see what was possible so I changed to manual mode, exposure compensation and auto ISO to see what could be done.  Auto ISO is not going to use the extended ranges of ISO.

AE7I2701.jpgAE7I2701jpeg.jpgI don’t know about the Nikon cameras but the Canon cameras tend to have three extended range ISO settings at the high end.  There is the highest ISO setting that it recognizes and then there are H1, H2 and H3.  They don’t name them with the actual ISO settings but you know what they are based on what you see on the camera.  The manufacturer does not label them as normal ISO settings because they do not stand behind them as a capability.  There is a good reason for that.  They are just like the highest Nikon settings.  Useful if you have no option but not very good otherwise.

The same was true with my older bodies.  They had a very high ISO range that was not great but it would do in a pinch.  At the Albuquerque Balloon Fiesta I shot an Aero Commander in the pitch black that flew over and I saw stuff in the shot I couldn’t see with the naked eye.  This is with a camera that is ancient by modern standards.  I expected a bit more with the latest generation.  Certainly, there is more to be achieved with what we have now. However, post processing becomes a part of the story.

My first experience with these shots was in Lightroom.  The shots did not look good at all.  However, there was a clue in all of this.  The first view in Lightroom is based on the JPEG that is baked into the raw file.  It looked okay until it was rendering by Adobe at which point it looked a lot worse.  This piqued my interest.  Sure enough, at the extended ISO ranges, the shots looked pretty awful.  Lots of purple backgrounds.  These were not going to be any good.  However, the initial preview had looked good., is this a case of Lightroom not being able to render the shots well?  I figured I should try going to the source.

AE7I2747.jpgAE7I2747jpeg.jpgAt various ISAP symposiums, the Canon guys have talked about how their software is the one that you should use since only Canon know how to decode their shots properly.  They have the recipe for the secret sauce.  Since Digital Photo Professional (DPP), Canon’s own software for decoding raw files, is so terrible to use, I never bother with it.  The raw processing in Lightroom (and ACR since they are the same) is so much easier to use normally and works really well. DPP is just awful in comparison.  However, we are now dealing with the extremes of capabilities of the camera.  The embedded previews seemed better so maybe it is possible that DPP will be able to do a better job.

You can now be the judge.  Here are some pairs of shots.  They are the same shot in each case.  The first is processed in Adobe Lightroom and the second is processed in DPP.  I think it is clear that DPP is better able to work with the raw files when it comes to extreme ISO settings.  The shots certainly have a more normal look to them.  The Lightroom shots look really messed up by comparison.  It doesn’t mean I will be using the extended ISO ranges on a regular basis.  Jumping to DPP for processing is not helpful on a regular basis.  However, if the need arises, I know that I can push the camera a lot further and use DPP to get something that is okay if not great.  This could be handy at some point.

High ISO Raw File Size

On my previous camera bodies I had occasionally shot at very high ISO settings as a result of the lack of light.  I had not paid a huge amount of attention to any secondary effects of doing so.  My current cameras had a work out in some very low light when I decided to test them in some rather unfriendly conditions.  When I was at home, I was running some disc backups and I found I could not get the normal number of files onto a single disc.  A quick bit of investigation and I could see why.  The high ISO shots had a significant increase in file size.  As I understand it, RAW files, while containing all of the data from the sensor, do have an amount of compression applied.  I imagine that the noise inherent in high ISO shots means that the compression is less effective as there is so much variation across pixels.  As an example, a shot at ISO 320 will average at about 22Mb.  The shots at ISO 51,200 are coming in at over 30Mb.  At ISO 204,000, the files can hit 40Mb. That is quite an increase!  Something to keep in mind when planning to shoot in very low light conditions.

Auto ISO

There is a function built in to my cameras that, until recently, I had never bothered to use.  It hadn’t been something that immediately grabbed my interest and so I had forgotten about it to some extent.  Therefore, when it could have been useful to me, I had not thought about how to make good use of it.  This is Automatic ISO.  This is an interesting idea when you start to think about it in more detail and one that might cause some to react in strange ways.

Many photographers will react poorly to the camera doing anything automatically.  They will say how they like to have control.  Then they will totally contradict themselves by telling you that they always shoot in aperture priority mode, totally ignoring the fact that the camera set the shutter speed for them in this mode “automatically”!  Therefore, for anyone reading (is anyone reading?) who jumps to the “I am against automatic anything” approach, why don’t you go and analyze exactly how your camera works and you use it.  If you are totally manual in everything you set, congratulations.  You obviously don’t need to read this anyway.

For anyone else who is a little more open-minded and who hasn’t played with this capability, let me explain why I tried it.  Plenty of times I have the camera in aperture priority in a situation where it is quite dark.  I know this is not clever of me but I often notice that the shutter speed is low because I can hear that it is!  In situations like this I might then tweak the ISO setting to try and bring things back into a range I am comfortable with.  My technique for this is rolling the dial a bit and seeing what I get.  Not clever analysis by any stretch.

Recently I was shooting a job in natural light (or lack thereof) that started long before the sun came up.  I knew I was going to be using some pretty high ISO settings to get useable shots and this is when the auto ISO function came to mind.  I went to manual mode, set the aperture and shutter speed I wanted and switched ISO to A.  Now, it worked out what was needed to get the exposure right.  As the light conditions improved, the ISO got dialed down but I didn’t have to do anything other than find what I wanted to shoot, compose and get on with it.  The only limitation I had was that I don’t know how (or even if) you can add exposure compensation in this situation.  Something for me to research – maybe even take the dreaded step of reading the manual!

The results were very satisfactory.  I got the images I wanted and didn’t have to constantly wonder about whether my ISO setting was right.  Obviously, this is not a solution for every situation but it does provide a good approach in some conditions.  Maybe you will have a time when it is worth a go to.

When Does Noise Matter?

I will freely admit I am as much of a gearhead as the next photographer.  New toys always catch my attention and then it is a matter of time before the battle is won between my sensible side or my not very sensible side as to whether I am going to get something.  The price of said item may well have an influence on which side wins that battle.

One thing that is a popular discussion for the pixel peepers is noise.  Having started off with a Canon EOS10D when I first went digital and worked through a number of bodies since – none of which have left my ownership I must confess – I have seen some steady improvement in noise reduction capabilities although not always with as much benefit to the final image as I might have liked but I digress.

A while back I was shooting at the Oceana air show with two of my buddies, Ben and Simon.  We had trekked down from DC for the show and were greeted by less than ideal weather.  The cloud base was solid and low and a bunch of displays didn’t take place.  Some did though and we still had a good day.  Given the heavy cloud, though, we were struggling for light.  I was shooting mainly with the MkIIN and was up at ISO 800 for a lot of the time.

The MkIIN is well into the noisy range at 800 and I knew that was the case but there was little option.  A while after this show, Lightroom 3 came out and it had a lot of noise reduction built in that wasn’t in the previous version.  I took a look at some of the Oceana shots to see how much better they might look.  There was a noticeable improvement and I was happy.

Why am I discussing this now, over a year later?  I was mulling over this topic for some reason, probably related to another acquisition decision, and I wondered how the printed version was affected by this noise.  There are plenty of things that I fret over in an image when looking at it on screen, usually zoomed in far too close, that really don’t become apparent at all when printing.  Is noise one of those things that looks better on paper?

I picked one of the shots from that day to experiment with.  The shot in question is this one of one of the Blue Angels taking off.  Since there was the treeline behind, the gray sky was not an issue and the burner plumes show up nicely given how dark it is so I like the shot.  Now to check it out on a print.

One of the nice features of Lightroom is the ability to mess with the print layouts.  I made a couple of virtual copies of the image and one one of them did my best to optimize the noise reduction and on the other switched it off for the most part.  On screen, it did not look great.  I then set up a page in the print module with two cells right next to each other and put the left side of one image in the left cell and the right side of the other in the right cell.  It looks like a full aircraft if I get the positioning just right.

First I printed it on an 8.5×11 sheet.  If I look closely, I can see the divide.  It actually shows more in the background than on the aircraft.  It is visible but it isn’t as noticeable as you might expect.  This had got my interest!  What about the size of the print.  I repeated the layout on some Super B (13×19) paper of the same type and printed it again.

As you might expect, this time is is a little more noticeable – hey, it’s twice the size!  However, even now, while it isn’t great, it really isn’t that bad.  We are talking about turning the NR almost off.

So, what do I conclude from this?  Well, technology is going to always get better, both in camera and on the computer processing it and I am still going to be a sucker for a new piece of kit.  However, while there is a noticeable noise difference on screen, the print is really a lot more forgiving.  Maybe I should relax about it a lot more and just enjoy the shooting, even when the light is limited.