Home Forums Reloading Big Game Rifles Chronographs accurate in overcast-sky conditions?

Sorry for such a rookie question, but I plan to go to the range in the morn and the forecast is for overcast cloud ceilings in the 2000 foot range and 5-10 miles of visibility. I have never used my chrony in any condition but bright sunshine. Seems I read they tend to have problems in low light conditions. Any input would be greatly appreciated.

I used mine today without any problems. It was solid overcast. My Chrony Beta Master worked with and without the diffusers.

Ernie

Cloudy days are actually brighter to the sensor then a blue bird afternoon.
The clouds act as the defusers do and give a nice white even back ground to show the bullet against. Blue skys are dark and the bullet can blend in if the sun is at the wrong angle. I prefer clouds to sun anytime I`m clocking loads

Me too!

I agree with Joe. Cloudy, overcast days are better for chrono work.

If I had to wait for sunshine, I'd only get to use my crony a couple of times a year.

There's a reason copying machine backgrounds are white....it's easier to pick up images. Same for chrono's.

Thanks guys!

Dissenting vote here.

On the Chrony, if you leave the diffusers in place you absolutely will get low readings under cloudy conditions.

I can't say what the situation is without the diffusers.

However, there is cloud cover and there is cloud cover. Thin clouds are one thing, cumulus another, and heavy overcast yet another. So without the diffusers lighting conditions are not uniform. The sun, on the other hand, is pretty constant.

I do all my chronographing from about 10:00 to 3:00 (later in summertime) on days when the Chrony and tripod cast a distinct shadow.

And my Chrony was just the opposite. If the sun was directly hitting the sensors, it was very unreliable. I do not think I ever found the conditions perfect so that the diffusers actually shaded the sensors.

But if I hung a sheet of 4 foot by 4 foot cardboard on the south side of the Chrony and shaded the sensors from the direct sun, it worked very well. And it always worked well on lightly over cast days. You know the type of day where you can not see the sun, but if you are not careful, you will get a really bad sunburn.

I used to get readings that were different depending on the weather(sunny or cloudy). Tried bigger diffusers and shading apparatus with mixed results, then read an article by J.B. on chrony's and he suggested putting a piece of cellophane tape over each sensor. I did that, threw away the diffusers and have had consistant readings ever since no matter what the weather, I just use the rods for line of sight. The article was 3-5 yrs ago I think, mabye some one here will have a link to it.

Yep. I find my chrony reads artificially high in the bright sun

mod7rem, I remember that article and did the same with the tape. Kept the diffusers tho, but JB's tape idea works.

I tried the tape thing and it seemed to work for a while. Then it seemed like the chrono didn't work well with them at all. Not sure if my tape got old or what.
Right now my "diffusers" are made from the plastic from a cat litter container. (approx 2 gal. jug) They are kind of a greyish white. I cut strips and attach them from rod to rod with some small spring loaded "v" clamps. It looks like a hillbilly rig but reads consistant all the time.

Is there an easy way to calibrate or even find out if your chrony is accurate? I don't know if my Beta master Chrony is reading high or low. Seems some get higher reading with their meters.

I've yet to find a weather/lighting condition to cause my Oehler 35P to not read a velocity.

Alan

Oehler M35 and CED M2's don't care too much what the sky is like as long as it is, well, light enough to see the bull. After that, others become more sporty.......

Of course, my old Custom Chronograph would read the shot in a pitch black room.

Compare it to a M35 or M2.......

My present Chrony (my 3rd) only reads accurately on cloudy days, and is consistent with any kind of cloudy light.
I know this because I've compared it to the readings from my Oehler, which as alpinecrick suggests, really don't care about light much. (Though even Ken Oehler has suggested that bright sun is the enemy of any light-screen chronograph).

My first chronograph was a Custom Chronograph, and it was dead-on reliable.

By the way, the tape trick didn't work very well on this Chrony, though it has on others.

I have a Pact Model 1 and the only way I can get any readings is to set it up in bright sunlight so the shadow of the diffusers falls directly on the sensor. This sometimes forces me to hammer bullets into the sand in front of the firing line because the range faces south. Good thing it's private and has high berms for safety or I couldn't even use the chrono.