chrono question

[laserdoc]

If I have the sun shining into my sensors would it give me a lower fps reading?
I know,I know it is best on a overcast sky. I did have the sunshades on but the sun was coming in at an angle and not overhead. It was about 2PM.
This was my setup the other day when I had the lower fps on the berry hbrn with the n320.
Just trying to cover my bases for when I try again. Been waiting for a overcast day. Maybe later this week or next.

With colder weather coming in will I see a change with the N320 ? Is this powder sensitive to cold??
Also is HP38 sensitive to the chill,,,or since Im in the southeast does it not get cold enough to have to worry about these temp changes

[DDeslaur]

I don't know about the chrono but on the subject of the HP38 I live in Quebec and snowshoe during the winter.
I carry a handgun and use it to shoot targets with ammo loaded with HP38 and have found it just as accurate at -20 F. than at +25.
I wouldn't worry about temperature varations with the HP 38.

[IDescribe]

The effect I am 100% confident in is reflected in extreme spreads and standard deviation.  The device is simply not as precise with the sun high in the sky on a cloudless day.  I've had a few occasions where putting up a blind to cast a shadow on the sensors has cut extreme spreads significantly.  And on one day I had nothing with which I could set up a blind, and I ended up with consistently high extreme spreads that made the data look pretty much worthless to me.  One of the days where I created a blind and brought down extreme spreads, the data after the blind went up caused the data before the blind went up to appear higher on average than it should have been.  I did not duplicate those loads and check again, however, so I don't know for sure.  And I have not noticed a distinct trend up or down on other days when it's happened.   

I also know that my shiny pretty Berry's and XTreme Plated bullets seem to be affected by the non-diffused light more than my black moly-coated bullets.  I have read where you can reduce that by darkening the tips of the bullets with a black Sharpie.  I have not tried that yet.  The fact that it's worse with shiny plated bullets, however, raises the question of whether the problem is non-diffused light hitting the sensors or hitting the bullets.  I tend to think it's how the light hits the bullets, not the sensor, because the sensors on my ProChrono are actually recessed deep enough in the body of the chrono that I think I'd have to be near the Earth's equator between noon and 1:00pm for the sun to hit the sensors directly.  I just started thinking about this today at the range.  I've been "fixing" the problem by setting up a blind for the sensors, but in doing so, I've also been casting a shadow over the bullets as they pass above the sensors.  So my "fixes" would actually work in either case.

Sorry to broaden the question rather than answer it.      And how far into the southeast are you? 

[laserdoc]

Atlanta

[1SOW]

I use the CE Pro-Chro Digital and it's much less sensitive to light changes than the previous low-end Chrony I was borrowing from a friend.  Mine still 'sometimes' gives some weird readings with steeply angled sun-light     In the shade seems to work very consistently.
After that,  the big boys use a 'dog-house' with artificial light to get precise readings. 

Some I've read of, place a translucent/milky-looking piece of plastic ( like you might use to protect flooring from paint splatter)  over the whole thing and SAY it works well.  I don't know.

[IDescribe]

Atlanta

I lived in Chattanooga for a couple of years.  It gets cold enough up there to have some effect.  How much effect with what powders I couldn't tell you.  If you run some tests on it, I'd be curious to hear the results.

After that,  the big boys use a 'dog-house' with artificial light to get precise readings.

Some I've read of, place a translucent/milky-looking piece of plastic ( like you might use to protect flooring from paint splatter)  over the whole thing and SAY it works well.  I don't know.

Yeah, meant to go by Walmart on the way to the range this morning to get some colored Saran Wrap and see if that would work.  But I forgot.  I did, however, have a large cardboard box in the car, cut the lid flaps off, and stapled them to the forward diffuser on my chrono.  They looked like crap, but they worked great -- kept the top side of the whole chrono in shadow from 10:00-12:00:





As far as a dog house goes, I've never heard of that, but it's clear exactly what you're talking about.  Makes perfect sense.

[harkamus]

Atlanta

Well I'll be bleeped. We should meet up some day, if only so I can pick your brain on getting started with competition shooting.

I'll let you try out my Accu-shadow. I'm in Stone Mountain, but am in Atlanta during the week for grad school.

I've been meaning to find a place to chrono my reloads. Where do you set up your chrono? I have one of those fancy ones. Forget the name, but it's one of the better models. Could bring it with and compare data with your chrono.

Shoot me a PM some time if you're interested.

[laserdoc]

In jefferson,
 About 5 miles of 85. One exit up from chateau Elan. 30 min from the mall of GA

[laserdoc]

Atlanta

I lived in Chattanooga for a couple of years.  It gets cold enough up there to have some effect.  How much effect with what powders I couldn't tell you.  If you run some tests on it, I'd be curious to hear the results.

After that,  the big boys use a 'dog-house' with artificial light to get precise readings.

Some I've read of, place a translucent/milky-looking piece of plastic ( like you might use to protect flooring from paint splatter)  over the whole thing and SAY it works well.  I don't know.

Yeah, meant to go by Walmart on the way to the range this morning to get some colored Saran Wrap and see if that would work.  But I forgot.  I did, however, have a large cardboard box in the car, cut the lid flaps off, and stapled them to the forward diffuser on my chrono.  They looked like crap, but they worked great -- kept the top side of the whole chrono in shadow from 10:00-12:00:





As far as a dog house goes, I've never heard of that, but it's clear exactly what you're talking about.  Makes perfect sense.

I have some of that plastic tarp downstairs. I like the shade you put on. But I thought the sensors had to have a clear few of the sky,,,not the cardboard.. Thought about taping a small piece of that plastic over each sensor.   Or just wait for a cloudy day
I have the same chrono. Over on the Brain Enos forum a guy suggested turning the chrono on its side because you can tilt the head with that camera tripod.  But then it would not see the sky 

[IDescribe]

Sorry for the trick of perspective.      Here's a front view:



As you can see, I don't have cardboard directly over the sensor. 

I just read the instruction manual again, and it said outright that glare coming off the bullet plays tricks on the sensors when it comes to shiny bullets and bright light.  As far as the general impact of direct, non-diffused sunlight, it was less clear.  It seems, from reading about how it works, that a steep angle for the sun and non-diffused light might get enough "intense" light into the censor recesses to mask the light changes created by the bullets passing overhead, but that is my guess, not something the manufacturer said explicitly.

As far as the "clear view of the sky" goes, that's stated in the recommendations for bright days when the chrono is placed in shadow.  The purpose of the "clear view of the sky" seems to be to make sure that's there's adequate light for sensor function.  I don't believe that an obscured view of the sky in and of itself would be a problem as long as their was sufficient light otherwise. 

I've been thinking about a doghouse since 1SOW mentioned it last night.  I'm confident that's the way to go for consistent readings from one day to the next.  If I build one, and the Magic 8-Ball says "signs point to yes," I'll post pics of it.     I'll try to make it prettier than the above cardboard blind.

[laserdoc]

Ahhh I see said the blind man 
 I have seen pics of the chrono dog house online before. But thats just another thing and a big thing to load up and carry to the range.
 Build one up and lets see. Im in the middle of building a table for my Big Green Egg so I will leave the dog houe to you 

[1SOW]

to get some colored Saran Wrap and see if that would work.

Won't 'diffuse the light--too clear.  Shine a flashlight on it and see.

Wax paper would likely do a better job diffusing the light---as a guess.

I suspect a couple of feet square of the milky looking plastic tarp would likely help eliminate glare and concentrated areas of light.

[Wobbly]

Funny Story...
Out using my chrono Sunday afternoon trying to record some data in my notebook. The wind whipped my notebook open just as I fired and the shot ripped a page out. So I'm sitting there wondering what the white thing is floating all over the range in my periphery. 

[IDescribe]

I've lost data, but I haven't lost it that way yet.   

Actually, my favorite method is shooting the first ten rounds over the chrono before turning it on.  Makes me feel like a genius.

[1SOW]

THAT'S FUNNY!