CED M2 Chrony: Problems with bright or angled sunlight?

[ClemBert]

I just ordered a CED M2 chrony. It hasn't arrived yet but I had a question for those of you who has used one in bright sunlight.

Assuming you have the sky screens in place...have you had any problems with using it in bright sunlight?

My shooting mound is on the eastern edge of my property. Therefore I shoot from west to east. There are trees behind the mound. This means in the morning I'll be in the shade or at least filtered sunlight. However, as we move past mid-afternoon (say 4 or 5pm) the sun will be to my back. Does this open up the potential for problems with this chrony. I am not able to reposition myself to fire in a direction other than west-to-east. Hopefully, this won't be a problem for this particular chrony model.

 

[ClemBert]

Hmmm, no one has a CED M2 chrony 'round these here parts?

 

[RidgwayCO]

I don't have the M2, but have had good luck with the M1. All chronographs to a certain extent have problems with sunlight at "bad" angles. The reason I purchased the M1 was because of the infrared screens and battery pack. I use the infrared screens at the indoor range with an extension cord, and at the outdoor range with the battery pack. Totally eliminates the need for natural or incandescent light, and gives me very accurate readings. Hope this helps.

 

[cfullgraf]

I recently bought an M2 but have only used it once with no issues. With the Chrony that I still have, I made screens to go on the uprights when the sun is lower in the sky and the sensors are not shielded from sun.

I expect that I may have to do that with the M2 but the shields have a bit more width than the rods used on the Chrony. Time will tell. The shields are made from card stock and masking tape. Definitely 'rocket science".

I frequently shoot late in the day when the sun is not overhead.

Also, particularly with .17 to .224 caliber bullets, I sometimes find it helpful to mark a black band around the bullet to add to the contrast of the bullet as it passes over the sensors. A Sharpie(r) is part of my chronograph kit.

 

[mayfie]

Shielding chronograph from direct sunlight

I don't remember what my chrony make/model is, but I would like to offer a low-tech solution to your bright sunlight problem.

I use spring type clothes pins and cardboard from opened up cereal boxes or 24 can packs. I use a photographer's tripod. I can raise/lower the legs of the tripod, or tilt the head, which tilts the screens, and clamp the cardboard to the translucent screens
Adjust the set-up to shade the chronograph's eyes from direct sun. When you set it up, leave an adequate "tunnel" to shoot through. You may need to reposition things as the sun moves east to west.
Low-tech, but it solved my problem. Hope this helps.

 

[ClemBert]

The chrony still hasn't arrived yet. Should be here tomorrow. So, as I understand it, the sky shields provide "shaded or diffused" light to the sensors. Direct light into the sensors will screw up the readings? And, even light coming at a angle "under" the sky shelds will screw up the readings?

What about operating the chrony under a 10x10 pop up canopy tent? Will that work? Or, what about draping some cheese cloth over the sky shields? Or another idea would be to use rig up something to hold a 2x4 sheet of florescent light diffuser material?

Would any of these things work?

 

[MCMXI]

My shooting mound is on the eastern edge of my property. Therefore I shoot from west to east. There are trees behind the mound. This means in the morning I'll be in the shade or at least filtered sunlight. However, as we move past mid-afternoon (say 4 or 5pm) the sun will be to my back. Does this open up the potential for problems with this chrony. I am not able to reposition myself to fire in a direction other than west-to-east. Hopefully, this won't be a problem for this particular chrony model.

I've been using a CED M2 for a while now and for the most part it has been very good. Sometimes the light will be focused in such a way as to cause ERR messages but that only happens at a specific time of the day and time of year (~ 30 min. window in winter months). Our local range is configured NE/SW and we shoot in the NE direction. I figured that the sun was reflecting off a roof or building at the range. Basically, no amount of guesswork from us will change your reality. Local geometry is unique to every shooter. Every chronograph that I've used or seen works via contrast between the bullet and whatever is behind the bullet (as seen by the lens). Anything that affects contrast can/will affect the chronograph and the start/stop function. You'll just have to try it and see, but I'm going to guess that shooting east/west or west/east is just about the worst possible orientation for a chronograph, particularly if you shoot early or late in the day. The filtered sunlight may also be a problem if it's not consistent.

 

[cfullgraf]

The chrony still hasn't arrived yet. Should be here tomorrow. So, as I understand it, the sky shields provide "shaded or diffused" light to the sensors. Direct light into the sensors will screw up the readings? And, even light coming at a angle "under" the sky shelds will screw up the readings?

What about operating the chrony under a 10x10 pop up canopy tent? Will that work? Or, what about draping some cheese cloth over the sky shields? Or another idea would be to use rig up something to hold a 2x4 sheet of florescent light diffuser material?

Would any of these things work?

I think a pop up canopy may take out too much light. But try it, it may work fine. It would depend on how much light the canopy filters out.

You may be reading too much into this. There are conditions that the chronograph does not see the bullet, but in my experience, they are not frequent and can be easily corrected with a little pre-planning.

On a bright sunny day, I put the diffusers on. If it is overcast, I don't. Most of the time, that is all I have to do. I make sure the sensors are not shaded by trees or shelter roofs directly over head. They must "see" the sky.

If the sun is low in the sky and the sun is not shaded by the diffusers, I add some shields to shade the sensors. These are on the side and do not affect what the sensor "sees" in the diffusers. If things look right, but the sensors aren't seeing the bullet, a black mark band around the battery helps.

The IR lights improve the reliability at a cost. I don't have them yet. i may get them, I may not.

My Chrony manual had some good suggestions on improving reliability. I forget what was in the M2 manual