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Gary Poole

Member Since 09 Dec 2006
Offline Last Active Yesterday, 06:17 PM
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Posts I've Made

In Topic: Interesting Article About Slow Shutter Speed In High Speed Flash Photography

14 February 2019 - 08:00 PM

This is an extension of the basic theory of flash photography.  When you use flash there are 2 exposures:

  1. The ambient light exposure.  This is controlled by the aperture, shutter speed, and ISO.  This is the image we would get without flash.
  2. The flash exposure.  This is controlled by aperture, ISO, the flash intensity and duration, and the square of the distance of the subject from flash.  The flash exposure is very fast, 1/1000 sec or less, depending on the flash settings.  The only shutter speed requirement is that it be slow enough so that the shutter is fully opened when the flash fires.  On most cameras this is 1/250 or 1/200 sec. and slower.

These 2 exposures are superimposed on a single image.

 

As the author of the article demonstrates, if we set up our camera for a very small ambient exposure, the ambient part of the image goes black and the only visible exposure is caused by the flash.  We do just the opposite of this for fill flash.  We set the camera for the ambient light and slightly underexpose the flash exposure.


In Topic: New - Adobe Enhance Details

13 February 2019 - 10:05 AM

Photography Life has a first impressions article at https://photographyl...enhance-details


In Topic: Selling the D300-mixed feelings

17 January 2019 - 09:49 AM

So you had yours lR converted too Gary.

I thought converting my D300 would breath new life into a good friend after it was replaced with the later generation.  Unfortunately I never got excited with about using IR.  Choosing the standard conversion is probably the least exciting of the IR options, so that probably has affected my opinion of IR,


In Topic: Selling the D300-mixed feelings

16 January 2019 - 11:14 AM

My D300 story is similar to yours.  I'd been dragging my feet on going digital ever since Digital Darrell took the portrait that I use as my avatar with his D2X.  I could see every hair in my beard!  That was the picture that convinced me that digital had overtaken film.  But the price of the D2X was beyond my budget and besides it was too big.  I got tempted by the D200.  It's size and price were acceptable  but it's AF was a step backwards from my F6.  When the D300 was announced it covered all my objections:  it was about the same size as my F6, its AF and Matrix metering were both a step up from the F6, and the price was half of a D2X.  I ordered my D300 within 24 hours of its announcement.

 

I immediately fell in love with the D300 and I don't think I've used the F6 since.  I wasn't tempted to upgrade it until the D4 and D800/D800e were announced.  Having just received a nice inheritance I ordered a D4, and a few weeks later a D800e.  Thanks mom for your very nice gift to me.  Now the D300 sat on the shelf.  About a year later I sent it to Life Pixel for IR conversion.  I opted for the standard conversion.  Unfortunately I've never really been bitten with the IR bug, so the D300 spends a lot of time on the shelf with only occasional use.

 

I don't think I'll ever consider selling my D300 though.  I have to many good memories of using it.


In Topic: Coca Cola Datsun 510

01 January 2019 - 11:57 AM

Yes it was fun, but also expensive, even for a navigator.  The driver has the expense of equipping and maintaining the car.  The navigator pays the entry fees, fuel, and room and board during an event.

 

It took a while for me to actually enjoy it.  During the timed sections, navigators spent all their time looking at the route instructions which were shown with 1/100 mi. (16 m.) resolution.  It was pre GPS times, so we used precise mechanical odometers with internal changeable gears selected to match our odometer calibration to the rally master's odometer.  The navigator would count down 1/100th of a mile increments while approaching a turn ("right in10, 9, 8 ...").  If the navigator started counting too soon, time would be lost because the driver started braking earlier than necessary.  If the navigator started counting too late, the driver could overshoot the turn.  Rallies were run at night to minimize other traffic on the route.  On the timed sections navigators spent most of their time reading the instructions and odometers with a small map light instead of looking out the window.   The car was bouncing and sliding on the dirt roads with relatively high G braking and direction changes.  I took a couple of events before I was able to avoid feeling nauseous.

 

Fortunately I was only involved in one accident in a rally.  We went off the side of a narrow road along the side of a hill near Chillicothe, Ohio,  We ended up upside down with the wheels about 10 feet (~3 m.) below the road we were on.  We were hanging upside down in the 5 point seat/shoulder harnesses with the roll bar keeping the roof from collapsing on us.  The worst problem was getting up the courage to push the release button to get out of the harness. We weren't hurt, but worried about falling head first onto the roll bar and the inside of the roof.  After our Datson 510 was turned right side up and pulled back up to the road we able to drive it away with just some bent sheet metal and a broken windshield.