JakTrax
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Certain Airline Schemes That Can Fool Auto-focus

Sat Jun 23, 2012 5:40 pm

I'm sure many of you will be thinking, "Yeah, I know one that does that....."

One that does it frequently to me is the Skyteam livery, but only on the smaller types such as the 737 and A320. Every time I photograph the KLM 739 or Air France 320 I'm left with several blurry/OOF images and just one or two sharp shots. Odd because other, predominantly silver liveries such as AA and Germanwings are fine.

I wonder what goes on with the camera/lens to make this happen?

Another, similar issue is with Lufthansa Cityline's ERJ-195s; but rather than being blurry/OOF they always come out looking particularly soft. Not sure if it's the way the livery is applied to that particular aircraft but it sure is weird!

Anyone else have similar issues with any airline liveries?

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sat Jun 23, 2012 8:45 pm

I always used to have trouble with AA's MD80's and 738's.

-Matt
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darreno1
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sun Jun 24, 2012 2:37 am

There are a couple that seem to be more problematic but it also depends on the distance and/or the angle they were taken at, at least in my case. US Air's blue and white livery is one that comes to mind. I really despise that livery.
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sun Jun 24, 2012 3:03 am

Air Tahiti Nui's A340s. 95% of my shots of them are very soft and/or blurry. I even put that in one of my photo remarks, cause it took me many tries before I got a good one.

LH A340s also seems to come out softer than other airlines, though not unusably so.
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spencer
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sun Jun 24, 2012 5:56 am

The only reason I could see anything "fooling" the AF would be the focus point not looking onto detail.
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jun 25, 2012 12:09 pm

Quoting spencer (Reply 4):
The only reason I could see anything "fooling" the AF would be the focus point not looking onto detail

Precisely. This thread wasn't intended to ask why but to highlight which airline schemes have a habit of throwing off the AF.

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jun 25, 2012 1:12 pm

Quoting spencer (Reply 4):
The only reason I could see anything "fooling" the AF would be the focus point not looking onto detail.

Yes this puzzles me. The scheme should make no difference at all. However, I can think of 2 possible (though unlikely) explanations

1 - AF works by edges or contrasts. An aircraft has a combination of mechanical edges (doors, engines etc.) and painted edges (logos and liveries). I suppose it is not impossible that certain schemes do not in themselves provide good edges, and furthermore camoflage the 'mechanical' edges.

2 - Infrared. DSLRs filter infrared light, but not completely (apparently effectiveness various with make and agel of camera).
Some of you older folk may recall a time when lenses had a mark on the focus ring to indicate infinity when using infrared light, which is a bit different to normal light. Is it possible that certain schemes are highly reflective of infrared, enough to throw off the AF?

Cheers,

Colin
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jun 25, 2012 1:59 pm

Quoting ckw (Reply 6):
Is it possible that certain schemes are highly reflective of infrared, enough to throw off the AF

Very likely I'd say. Another guess of mine would be that highly-reflective schemes (e.g. predominantly silver) reflect so much sunlight if caught at certain angles that the AF effectively has nothing to focus on - the theory here being that AF can't lock on to what is really nothing more than a shape-shifting 'orb' (or a collection of 'orbs') on the fuselage that has no real depth or solidity.

Such theories however don't explain why one predominantly white livery turns out okay when another does not. LH for example can be so temperamental, with many people reporting softness with the livery; but AF seems to photograph nicely. The schemes aren't too different, unless it's to do with opposing contrasts (i.e. the pure white of LH with bold, dark text).

Then again, it may just be down to the fact that AF aircraft are rarely pure white........  

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jun 25, 2012 4:00 pm

Quoting JakTrax (Reply 7):
Such theories however don't explain why one predominantly white livery turns out okay when another does not

Actually that's what made me consider the infrared theory - while to the naked eye white paint looks like white paint, a wide variety of non-visible finishes may also be involved - either as part of the paint, or an additional coating - to avoid dirt, reduce yellowing etc. These different coatings may respond to IR light differently. I guess a test would be to photograph various white schemes with infrared film (or an IR enabled DSLR) and see how the schemes look in infrared.

Cheers,

Colin
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RE: Certain Airline Schemes That Can Fool Auto-focus

Tue Jun 26, 2012 7:33 am

The one that sticks out for me is the One World AA 757 !

Very tough to focus on .... have to rattle of a few just in case !
Cant think of any others to be honest , maybe also that the only times ive had the opportunity to shoot it the weather/light hasn't been perfect

regards

[Edited 2012-06-26 00:37:09]
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Tue Jun 26, 2012 2:04 pm

Quoting vir380 (Reply 9):
The one that sticks out for me is the One World AA 757 !

Now oddly I don't have trouble with that one; but then again I've only ever shot it in the sun. I can imagine it being a bugger in not-so-good light!

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Wed Jun 27, 2012 7:18 am

For me I will have to say LOT 767, it's pain in the butt and when you get it right, the whites colours looks very harsh.

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RE: Certain Airline Schemes That Can Fool Auto-focus

Wed Jun 27, 2012 11:27 am

I always had trouble with Sterlings bright red livery, always came out so soft they could not be fixed in Ps. But that problem kind of went away when Sterling went bust  
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Wed Jun 27, 2012 12:58 pm

Funny you should say that John as I shot that once at EMA and every single one was really soft, despite having captured them at 1/640th shutter!

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Wed Jun 27, 2012 9:58 pm

I used to have problems with the AA liveries, but a polarizing filter is your best friend! Took that moment of when the camera was unsure of what to do and blew it completly out of the water. Then, you not only get the benefits of the filter, but you can see right into the cockpits!
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sun Jul 01, 2012 7:19 am

The only time i have photos come out OOF or not as sharp as i'd like is down to user error and not the camera, most of the current crop of cameras shouldn't and really don't lose focus easily. If they do then it's probably something the operator isn't doing quite right!

Chris
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Sun Jul 01, 2012 10:29 pm

Quoting chris78cpr (Reply 15):
The only time i have photos come out OOF or not as sharp as i'd like is down to user error and not the camera, most of the current crop of cameras shouldn't and really don't lose focus easily. If they do then it's
probably something the operator isn't doing quite right!

I don't agree. It's highly unlikely for example that I happen to lose the plot every time the KLM Skyteam comes at me. User error would be much more random and not feature the exact same aircraft time after time. As Colin points out above, there are tricks of light that could quite easily knock a camera's AF out slightly, or otherwise cause it to lock on to something that's not really there.

Additionally, poor quality lenses with sluggish AF can have a habit of 'hunting' excessively. With such lenses it doesn't matter how good the camera its mounted on is!

I maintain that certain schemes inherantly don't come out as sharp of in-focus as they should.

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 8:37 am

Quoting JakTrax (Reply 16):
As Colin points out above, there are tricks of light that could quite easily knock a camera's AF out slightly

Hmm - I don't think that's quite what I said - I suggested 2 theoretically possible, though unlikely, scenarios.

Bottom line is that 9 times out of 10, for any focusing or exposure issue, the answer is 'user error'.

However, the 'difficult scheme' issue has come up again and again from a variety of people which suggests there may be something to it.

Yet there seems to be no pattern to the schemes which are difficult unless the factor is a hidden one (type of paint or top coat used) - indeed perhaps even the cleanliness of the aircraft could be a factor.

For now I don't think a definitive answer is possible - a more systematic approach is required. Perhaps if 2 or 3 photogs were to spend the day together shooting a variety of schemes in identical conditions it might be possible to determine statistically which schemes (if any) caused AF problems - from that it may be possible to think of causes.

But consider this - if there were a scheme or coating which disrupted AF wouldn't this would have been identified and applied to military aircraft? I haven't seen any military schemes mentioned as problematic. So perhaps local (ie. atmospheric) conditions are also an important factor. Eg. a certain colour scheme combined with high humidity or high temperature.

As for myself - in various kinds of shooting I don't think I have identified any subject/surface/color which by itself tends to cause poor focus - I think I have always been able to attribute it to something else (light, contrast, my mistake, or - of course - equipement!). But I have had issues with image quality based on certain colours - red/orange always seem to lack detail compared to other colors ... something I've always attributed to the bayer filter used by most DSLRS (though it may be an issue in RAW processing).

Cheers,

Colin
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 3:51 pm

It just seems odd to me that every time I photograph the KL Skyteam 739 most of the shots come out soft or even blurry. Also, every time I photograph an LH ERJ the results tend to look soft. I can't believe that user error would consistently happen ONLY when photographing these two; it would be far more random. I'm not 100% sure what it is but with the KL Skyteam I really do think it's a trick of light somehow throwing the AF off.

I'd also agree that predominantly red/orange/yellow liveries also make detail look softer. Would this be attributed to user error too? I can assure you that, after photographing aircraft with an SLR for 23 years, it's not user error! Cameras and lenses are only machines and like all machines CAN get it wrong.

Karl
 
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 4:27 pm

I do believe that the nature of the Bayer filter (which essentially 'mixes' light of different colors) will have an effect on what information the sensor records - there are twice as many green sensitive photosites as there are blue or red.

Hence I think with some colors it is possible that less detail is being recorded than with others. I experimented with this by photographing a traffic light shining green, then red. No question in my mind that the lit green light contained more detail than the lit red. Of course this may be due to the RAW conversion software.

So, is it possible that what people are describing as soft focus is actually lack of detail?

Cheers,

Colin
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 5:08 pm

Quoting ckw (Reply 19):
So, is it possible that what people are describing as soft focus is actually lack of detail?

I think you've hit the nail on the head there Colin. Certainly in the case of the LH ERJs I reckon it's more a lack of detail than actual softness, but being an all-white aircraft I've no idea why. Perhaps it's the bold, blue font responsible rather than the fuselage colour?

It could be something to do with tones and contrast. I always find with DHL that the red registrations over the yellow finish always look soft (not blurry). The contrast between red and yellow isn't as great as that between tonal colours (black and white). This is also the case for a lot of other liveries.

While I agree that many OOF/soft images are down to technique or optimistic camera settings there are definitely some schemes that just don't photograph well. Interestingly I never had such 'nemesis' schemes when I shot film/slide, so that pretty much rules out user error. Having said that we could never scrutinise 35mm format images to the extent we do with digital so perhaps that point is null.

Whatever it is, it's there. Unless of course anyone is seriously suggesting that I just happen to get my settings wrong only when the KL Skyteam 739 passes my lens?

Karl

[Edited 2012-07-02 10:12:01]
 
chris78cpr
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 8:28 pm

Quoting JakTrax (Reply 20):
I think you've hit the nail on the head there Colin. Certainly in the case of the LH ERJs I reckon it's more a lack of detail than actual softness, but being an all-white aircraft I've no idea why. Perhaps it's the bold, blue font responsible rather than the fuselage colour?

It could be something to do with tones and contrast. I always find with DHL that the red registrations over the yellow finish always look soft (not blurry). The contrast between red and yellow isn't as great as that between tonal colours (black and white). This is also the case for a lot of other liveries.

While I agree that many OOF/soft images are down to technique or optimistic camera settings there are definitely some schemes that just don't photograph well. Interestingly I never had such 'nemesis' schemes when I shot film/slide, so that pretty much rules out user error. Having said that we could never scrutinise 35mm format images to the extent we do with digital so perhaps that point is null.

Whatever it is, it's there. Unless of course anyone is seriously suggesting that I just happen to get my settings wrong only when the KL Skyteam 739 passes my lens?

Without meaning to sound rude, could it be your overly high expectations that are causing you think that certain photos are soft?

I mean we have all had it when you get back from a session, look at a shot that you were excited about and it's not quite perfect and it's down to user error. I have then gone to shoot it again when the starts align and will have high expectations of the shot that will result. Maybe it's that, that is causing you to be hyper critical of these photos?

Are the resulting photos of KLM skyteam 739's or LH ERJ's not good enough to get in the database?

Chris
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 8:30 pm


View Large View Medium
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Photo © Karl Nixon
View Large View Medium
Click here for bigger photo!

Photo © Karl Nixon



These both look just as sharp as your other uploads?

Chris
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JakTrax
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RE: Certain Airline Schemes That Can Fool Auto-focus

Mon Jul 02, 2012 9:31 pm

Quoting chris78cpr (Reply 21):
I mean we have all had it when you get back from a session, look at a shot that you were excited about and it's not quite perfect and it's down to user error. I have then gone to shoot it again when the starts align and will have high expectations of the shot that will result. Maybe it's that, that is causing you to be hyper critical of these photos

Like everyone else I get back from a session occasionally and find that an image that looked perfect on the review screen isn't actually as sharp as I thought it was - but as you say, that's usually due to an error on my part; an error which I usually recognise in hindsight. Luckily it doesn't happen often but a misjudgement I sometimes make comes as a result of trying to maintain ISO200 and at least f/6.3 in low light when really I shouldn't be afraid to bump it up to ISO250 or even open the aperture to f/5.6.

In the sequence of shots including the KL image you've linked above there were 8 images. That was the only one that came close to sharp and although it wasn't far out it took more sharpening than every other image that day. All shot at f/9, at between 1/640th and 1/800th, at my typical settings for such light. The LH ERJs are a slightly different story because they actually look sharp except for the titles, which always look really soft. It's just a case of applying extra sharpening to any text on the fuselage.

I like to scrutinise my images and I often have high expectations - but 99% of the time I get them home and they are equally as impressive as they looked on the camera screen.

So to conclude, I recognise user error as a factor if it's responsible for an image not being up-to-par. But with KL Skyteam I can never find anything wrong with the settings or the technique used to capture the image. I guess we'll probably never know why certain liveries can prove awkward but until you've experienced it yourself it's perhaps hard to grasp. I'm literally out every sunny day at an airport so I most likely notice it a lot more than those who are only casual.

Cheers,

Karl

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