how to achieve prop blur

[Dave O'Brien]

Thanks Tony,

does lighting make a difference at all? If I'm using shutter priority would I go lower on a cloudy day or does that not have any effect?

[Tonyz]

Well....remember that the lower you go with speed the wider open your apperature will be, and you begin to lose DOF.    Even worse is the camera shake etc of slower shutter speeds.  Look through the Civil Helos threads and take a look at the stuff Dan Megna, Neville Dawson and others have shot.  It is just tough to pull off a good rotor disk. 

It does help when you have a multi blade rotor as opposed to a 2 blade (Hughes 500 vs a Bell Jet Ranger....)  I think this OH-58 was shot at 1.60th...

[Dave O'Brien]

Wow, those are some great shots   

thanks for the help Tony, I'll keep messing around and see what happens. The beauty of digital, don't like it, toss it 

[Jorgo]

Well....remember that the lower you go with speed the wider open your apperature will be, and you begin to lose DOF.

Tony, with a slower shutter speed, won't the aperture become smaller, thereby gaining you more depth of field?

[Pierce]

Jorgo is right on this one 

[mustangsx2]

This 1st pic (sorry it was posted on another thread) was shot on take-off at 1/160 when the Sea Fury was at power.  I would love to get a full arc from this angle, but I have trouble with the fuselage staying  sharp from front to back at 1/60 or slower.  Maybe some of you can help me with my math.  If the Sea Fury is going 120 mph just after lift-off, it is moving about 176' /sec, or 2.933'  in  1/60 sec.  So the plane moves almost 3' during the exposure of 1/60. Maybe this is why I have trouble with head-on shots at slow speed?   Depth of field should handle the focus, but the image is getting larger during the exposure (marginal but larger).   There is a slight pan and I rule out camera shake when part of the plane is sharp.

 I can get the nose sharp, but not the canopy, or the reverse.   See the 2nd shot, at 1/40 on a low pass for overhead break.  This time the plane is moving I would guess about 230? +- mph.  At 230 mph  the plane is moving 337.33 ft/sec or 8.43 feet during the 1/40 exposure.   

I would like to get some of you FCer's  input.

Curtis

PS: of course the best way to solve this is to be moving with the aircraft. 

[Pierce]

I can get the nose sharp, but not the canopy, or the reverse.   See the 2nd shot, at 1/40 on a low pass for overhead break.  This time the plane is moving I would guess about 230? +- mph.  At 230 mph  the plane is moving 337.33 ft/sec or 8.43 feet during the 1/40 exposure.

I would like to get some of you FCer's  input.

Curis,
Your math is absolutely correct. Its amazing that all are shots aren't blurred when you look at the numbers. These numbers also demonstrate how hard it is to get an apposing pass with the jet demonstration teams.

[M.M.]

Something that nobody's mentioned on this topic is lens diffraction.  Hasn't anybody [else] found that their pictures became softer when stopping down to get prop blur?

When light passes through an opening, the rays that pass near the edge are bent.  If the opening is a camera aperture and the light is supposed to be focused to a point on a sensor or piece of film, the rays that were diffracted will make a fuzzy halo.  As the lens aperture gets smaller the effect becomes more noticeable because a larger portion of the light is affected.  On 35mm lenses, diffraction usually becomes noticeable around f/16 and the sharpness of an image will quickly fall off at smaller f-stops.

Now, using the sunny-16 rule and 100 ASA, if f/16 is my last sharp aperture my shutter speed has to be 1/100th -- enough for a full arc in flight but not for an idling piston engine.  If I go to much slower shutter speeds, I may get better prop arcs but my pictures will be much softer because of the smaller aperture.  Likewise if I keep the same shutterspeed but use a higher sensitivity.

How have people dealt with this?  I'm particularly interested in hearing what D70/D70s users have to say, as 200 is their maximum ISO setting....

-M.M.

[RichardVM]

Something that nobody's mentioned on this topic is lens diffraction.  Hasn't anybody [else] found that their pictures became softer when stopping down to get prop blur?

When light passes through an opening, the rays that pass near the edge are bent.  If the opening is a camera aperture and the light is supposed to be focused to a point on a sensor or piece of film, the rays that were diffracted will make a fuzzy halo.  As the lens aperture gets smaller the effect becomes more noticeable because a larger portion of the light is affected.  On 35mm lenses, diffraction usually becomes noticeable around f/16 and the sharpness of an image will quickly fall off at smaller f-stops.

Now, using the sunny-16 rule and 100 ASA, if f/16 is my last sharp aperture my shutter speed has to be 1/100th -- enough for a full arc in flight but not for an idling piston engine. 

With good quality lenses, Nikon and Canon (Yeah, I know I'll take some heat for not including other lens manufacturers, but I call it the way I see it) diffraction shouldn't become an issue too quickly with 35mm lenses unless you're shooting into the light source, in which case your pretty screwed anyway. I have not noted much if any degregadtion at f/22 or even f/32 with lenses stopping down that far. Thus far its been a non-issue, although getting ISO down to 100 in the D2X was certainly nice. It is a headache trying to get low enough shutter speeds in bright light conditions with the D70 (You got the D70s right?) or D2H.

Didn't do it myself, but I know of plenty of folks using ND filters, and have seen some pretty good reviews of the variable density Singh Ray filters, although most shooters noted a very slight color shift. But if you want to shoot really slow, there are not a lot of options. I'm talking really slow, like waterfuls and streams at a couple seconds... If you like a polarizer, the 1.5-2 stops should be just right for shooting planes, plus it gives you much better saturation.

Welcome to the digital age Mark. now what's with the Danish flag?

Richard

[PhotoDK]

I've really enjoyed the discussions on prop blur's and the photos, but I'm having a bit of a difficulty with some of the numbers that everyone is throwing out.  So I thought I'd create a little table giving the maximum allowable shutter speed for a given (typical) RPM and number of blades to obtain a full 360 degree prop arch.

   Number of blades         
Prop RRM      2      3       4       5
   1200   1/40   1/60   1/80   1/100
   1500   1/50   1/75   1/100   1/125
   1800   1/60   1/90   1/120   1/150
   2400   1/80   1/120   1/160   1/200
   2700   1/90   1/135   1/180   1/225
   3000   1/100   1/150   1/200   1/250

During normal cruise operation, I would expect most general aviation airplanes to operate at around 2400 RPM.  I believe most turbo props run around 1500 - 1800 RPM.  Maybe another FCer could fill us in on radial engines and other warbirds.  Helicopter, that's another story, I think the main rotor is between 300 and 400 RPM and of course the tail rotor is much much higher.

[mustangsx2]

...  Are the fighters flying slow enough to have the settings at 250 and still keep everything crisp? ...

We shoot warbirds at shutter speeds 1/250 (and slower) all the time (with a few through-aways  )  If we can get them sharp much of the time, then the same should be true for a jet moving at the same speed.

Your pan needs to be on target and your hand steady.  Slow shutter = better prop blur = small aperature = better depth of field = better chance of camera shake with longer lens and better chance of an imperfect pan. Yes it is a trade off, but there is not much choice of max shutter speed with warbirds.  For me, 1/250 for warbirds is only  when they are at full power (or I really need the shot), Heritage Flights 1/200, radial engines drop another notch of shutter speed.  Pan to a point on one of the aircraft and smoothly sqeeze away.

[Dave O'Brien]

 

thanks for that info, I'll try it at Nellis this year. Just read 2 Mustangs with the F-4 and the F-22 

[RichardVM]

The shutter speed for a single airplane is one think, but the problem with the Heritage Flight and any multi-plane formation is the relative motion of the aircraft viewed through the lens. As you're panning, the aircraft are moving at different speeds and in different directions in the viewfinder, and across the CCD. Add in the fact that the pilots are usually moving around in the formation to, and that is what makes it so tough to shoot the Legacy and Heritage flights and getting all the jet and prop aircraft sharp yet maintaining a nice prop blur..

Someone used a good term: trade off. Shoot a higher shutter speed (or get them to fly all jets, like the Oceana Heritage with 2 F-86's) and stop the prop, or shoot a slower shutter speed to get the prop blur and risk blurring some of the planes....personally, I'll risk the slower shutter speeds.

Richard

[ExitRow]

In regards to the Heritage Flights... I shot this a few years back:



And although there's not as much prop blur as I'd normally like, this time I think you can see why I was happy with what I got. I could lie and say "I totally meant to catch the blades in exactly that position." But I won't. It was luck. Well... luck mixed in with decent timing on the shutter, Canon IS on the 600mm and a very heavy, stable Gitzo tripod.

All those came together and created what you see above.

Besides the props, I like the barely visible heat distortion from the Eagle's jetwash as well. (The blurry part of the canopy and right vert stab.)

[swanny]

I was wondering the best camera/sutter settings to get the prop blur.  I use a canon MKIIn if that matters.  I am usually a feathered bird photographer...but it is pretty slow around here and I am getting bored.  The accessability of the MSP, and my uncles antiques at the AAA in Blakesburg,IA have me pursuing this more and more.  Thanks for your help.


Jon Swanson