UV or not UV

Someone from Viewfinders posted a video discussing the use of UV filters on the front of digital cameras and whether this was a valuable thing to do.  Their conclusion was that, contrary to film, sensors from digital cameras are not sensitive to UV so there is no advantage to  filtering out UV.  They did feel strongly that UV filters provide a valuable safety measure to protect the front lens element from dust, scratches and other physical  ailments.  I have always used UV filters for that purpose, but it got me to thinking about such filters and whether they really reduce the UV or whether they could be a simple glass plate with no UV attenuation.

To investigate this, I performed a simple homey experiment.  I have a black-light lamp that was made for inspection using fluorescent penetrants.  The hand-held lamp has a filter that blocks any visible light and only UV is emitted.  It is well known that certain fabrics, such as white cotton will fluoresce under UV.  If you put a white handkerchief under the black-light, the fabric will glow with a very bright white.  I know that you cannot see the UV, so the filter would be useless if trying to see attenuation of the UV.  However, if the filter blocks UV, then it should block the fluorescence of the white cotton.   I held several UV filters made by different manufacturers between the UV source and the handkerchief.  In no case was the fluorescence reduced.  My conclusion is that the filter only works for some remote wavelength, different from my lamp, or else they are essentially just plain glass. 

I can think of another test I could do in the summer.  I could tape some filters to my skin and sit in the sun for awhile.  If the UV from the sun is responsible for sun tanning, then there may be some lighter circles in the area of sunburn.  Maybe later.

Selfie

Ted Grant's assignment last week was a self portrait with imagination.  He specifically did not want forty shots of people looking into mirrors.  I tried a little variation on that approach.  I call it "Portrait of me photographing a camera on a tripod".  I wanted the image to suggest I was looking at myself in a small mirror.  But, if you think about it, you realize that couldn't be the case.  The camera I'm holding has to be pointed at the camera taking the picture and that one is not shown.  Anyway, a fun exercise.  Comments welcome.

Handy

The previous post was about the "Twilight Zone" assignment.  This week the assignment was "Dramatic Human Hands".  Since I already used the photo from the last post, I had to look for another subject.  I thought a shot of two pairs of hands in a nail salon would be a good subject.  I approached the manager of the nail salon in our local Walmart.  Turns out she didn't do English.  But there was a young woman sitting up front who took pity on me and offered to pose.  Here is the result I submitted.

 

Twilight Zone

So I have been a subscriber for a number of years to a mail list for the "Leica Users Group".  The LUG has members from around the world with a common interest in Leica cameras and lenses.  I have never owned a Leica nor do I really want to, but I have admired their performance and design philosophies for many years.  The LUG has recently started a weekly "assignment", run by a veteran Leica photographer, Ted Grant, from Canada.  Ted is in his 80's and retired from many years of photojournalism and other photography.  He is highly honored in his home country and has many fans in the LUG.  Ted names a topic each week and lets members post entries on-line to the mail site.   Then on the Sunday after the assignment he posts critiques of each entry.  No winners, no prizes, just an opportunity to get feedback from an expert.

Last week's topic was "Twilight Zone" with each entrant to interpret the topic as he chose.  Turns out hardly anyone interpreted it as Ted imagined.  My interpretation was "twilight" in terms of the twilight of your lifetime, i.e., old age.  That interpretation was suggested by my spousal unit and her arthritic hands are the subject, though she is very embarrassed to have anyone see their condition.  I don't share that concern. They are what they are and they represent over seventy years of hard work and dedication as a wife and mother.  Certainly nothing to be ashamed of.

Here is the photo.  Comments are welcome.

Four off the Floor

So I went to the Tejas Rodeo last night specifically to take some photos of barrel racers.  I had taken one shot on a previous visit, but did not have the ability to get above ISO 3200 and it was pretty noisy.  This time I was prepared to shoot up to ISO 12,800 which I thought would be helpful in the relatively low light in the arena.  It is surprising how much dimmer the light is for photographs than with the eye.  I needed to get shutter speed faster than 1/100 for a good action shot.  I had an 85mm f1.4 lens and a 45mm f2.8 in case I was too close for the longer lens.  Turns out I was in fact too close to the barrel I picked out, so I used the 45mm.  I shot burst mode giving me three or four shots as the rider circled the barrel.   Those came out OK so I will  probably enter one in the Viewfinders challenge this month.  In barrel racing the riders circle three barrels and then ride fast as possible to the other end of the arena.  Total time is the measure of their performance.  Most times were in the range of 15 to 17 seconds.  If you dislodge a barrel, you are penalized time.

We had one contestant who had won the national championship in barrel racing.  I think she is from Bandera.   The photo shown here is of her sprint back down the arena.  Her total time was 15.166 seconds which was the fastest time ever recorded for the Tejas Rodeo.  I do not know  horses, but hers was magnificent.  I think she is a very good rider, but the horse deserves a lot of the credit.  This photo I include to show all four hooves off the ground during the gallop.  I believe that was one of the first dramatic findings when the movie camera was being developed.  They found a single frame that showed all four hooves of a running horse off the ground.  That had been debated prior to that time. 

Long Exposure

The May challenge for the Viewfinders camera club is a B&W shot using an exposure time of greater than 1 second.  One of my ideas is shown below.  I remember from the olden days of film cameras that you could take multiple exposures of a scene with moving objects and when you finished the multiple shots, the moving objects would not show in the picture because of their short appearance time compared to the whole shot. I thought I'd try something similar by using a long exposure.  My target was the I-10 interchange at Loop 410.  It is probably the busiest intersection in the city, with traffic on all connectors at most all times of day.

There is a hotel, the Marriott Northwest, near the interchange.   My hope was that there would be a publically-accessible window on an upper floor where I could take a shot of the highways.  The hotel has 11 floors.  I took my tripod and camera up the elevator to the 10th floor and there was a suitable window right at the elevator.  I had three 8x neutral density filters to give a nine-stop attenuation.  It was about 3 PM on a Friday so there was a lot of light and also a lot of traffic.  The photo here was a 60-second exposure at ISO 100.  The only complaint I have is the reflections from the inside of the window.  They are a little distracting, but I think I proved the point of removing the moving cars from the scene.  They occupy probably less than 1% of the time at any one point on the road, so they do not show in the overall shot.

Murder Trial

I’ve been thinking about the Jodi Arias murder trial.  It has been on TV a lot.  The “’talking heads” on TRU TV, Nancy Grace and other shows are having a field day commenting about the trial along with their on-air “experts” who are mostly law enforcement types or attorneys.  Much has been said about Ms. Arias’ response to cross examination by Mr. Martinez, the prosecuting attorney.  She rarely answers a question with a simple “yes or no” answer, often qualifying her answer or commenting on how the question was framed.  I have heard a lot of opinion expressed that she should be forced by the judge (or someone) to answer the questions properly and that she should not be allowed to lie as much as it seems she is doing.

I keep thinking that this is a death penalty case.  What does that mean?  It means that Mr. Martinez is trying his best to convict this person and send her to the death chamber.  If his arguments prevail with the jury, it will result in Ms. Arias losing her life.   So we have on the one side, Ms. Arias and her attorney trying to get her off, or at least to save her life.  And on the other side, the state, through Mr. Martinez, trying to take her life.  Now never mind whether she is guilty or innocent or something in between.  She and her counsel are the only ones trying to save her life.  She is facing questioning from someone who, if successful, will kill her.  So how much truth and cooperation does she owe to a man who wants her killed?   If it was just a matter of avoiding a fine, or even some jail time, yes, maybe she should “fess-up”.   But it is her life we are talking about.  The end of her existence.   It seems to me she is justified to lie, scream, or clam-up if it is necessary to save her life.   Some seem to suggest that she should cooperate with the prosecutor in the name of justice, even to the point of sacrificing her life.  I don’t think so.    If you are in a life or death situation, you do what you can to save your life.  Now I am not talking about those cases where you put your survival ahead of someone else’s or where you might sacrifice yourself to save others.  That is not the case here.  Travis Alexander is already dead.  None of the lawyers or jury members is in danger whether Ms. Arias lives or dies.  She is on trial with her own life and no one else’s at stake.   I say she should use whatever intelligence and cunning she can muster to save her life.  If she pays a price of perjury or jail time or whatever, so be it.   Without a life, none of those things have any significance.  

 

As always, I reserve the right to change my mind later.  8=)