I have a Chrony F-1 . It had the shade screens. When were those supposed to be used ? It was a Blue November sky today at range and I think the chrony was reading a 100 FPS high? I accidentally shot one of the shade screens a while back. So I just use the steel rods as a guide. I've used it like this many times with no false readings I don't think. What could be the cause ?
Questionable Chronograph readings?
- Thread starter Worker
- Start date
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Larry Willis
Guest
Worker,
Chronographs are extremely sensitive devices, and they can be problematic under the best conditions. However, I've done lots of testing with my Pact chronograph, and I've found how to make it almost 100% reliable (and more accurate) if you give it a few simple modifications. It helps any chronograph to put flat black paint on any reflective parts of your skyscreens and tripod that face upwards. Any shiney reflective surface near the skyscreens, and below the bullet, can reflect upwards to the bottom of the passing bullets. That light reflection makes your bullets harder to detect. Also, be aware that chronographs will use up their batteries VERY quickly.
I have a Tech Tip article on my website about improving the reliability of chronographs. Visit http://www.larrywillis.com
- Innovative
Chronographs are extremely sensitive devices, and they can be problematic under the best conditions. However, I've done lots of testing with my Pact chronograph, and I've found how to make it almost 100% reliable (and more accurate) if you give it a few simple modifications. It helps any chronograph to put flat black paint on any reflective parts of your skyscreens and tripod that face upwards. Any shiney reflective surface near the skyscreens, and below the bullet, can reflect upwards to the bottom of the passing bullets. That light reflection makes your bullets harder to detect. Also, be aware that chronographs will use up their batteries VERY quickly.
I have a Tech Tip article on my website about improving the reliability of chronographs. Visit http://www.larrywillis.com
- Innovative
F
f d shuster
Guest
Chrony F1
Worker: I have, and use the Chrony F1 also, on a sometimes basis. When the sky is overcast, results are excellent and trouble-free. I've also had excellent results when keeping the chronograph in the shade while using it, as in the early morning hours. Returned it for repair(?) several years ago, and it came back with the assurance there was nothing wrong with it. Anytime the sky is blue with the sun overhead ( using the sunshades, of course) there are problems. I'll try the black paint on the shades, as suggested above. Even with the "problems", still worth their minimal cost.
Worker: I have, and use the Chrony F1 also, on a sometimes basis. When the sky is overcast, results are excellent and trouble-free. I've also had excellent results when keeping the chronograph in the shade while using it, as in the early morning hours. Returned it for repair(?) several years ago, and it came back with the assurance there was nothing wrong with it. Anytime the sky is blue with the sun overhead ( using the sunshades, of course) there are problems. I'll try the black paint on the shades, as suggested above. Even with the "problems", still worth their minimal cost.
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Dennis Sorensen
Guest
If you are shooting through only one chronograph you never know if the reading is actually accurate... bullet glint, light conditions can cause an error not determined by only one set of screens...
That's why I love my old 35P... each shot is measured twice and compared... the computer marks discrepancies as unreliable and rejects that shot...
That's why I love my old 35P... each shot is measured twice and compared... the computer marks discrepancies as unreliable and rejects that shot...
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Dog's Elvis
Guest
If it is not fully extended (opened), readings will be high because the distance between sensors is decreased.
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Larry Willis
Guest
fd shuster,
Don't paint the shades! Paint the shiney parts of your tripod, mounting brackets and anything else that will reflect sunlight upward. The article on my website also explains how to avoid problems with weakened batteries ...... that's a major headache with chronographs
Innovative
Don't paint the shades! Paint the shiney parts of your tripod, mounting brackets and anything else that will reflect sunlight upward. The article on my website also explains how to avoid problems with weakened batteries ...... that's a major headache with chronographs
Innovative
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f d shuster
Guest
sunshades
Larry Willis: Thank you for the "heads up". Read your post & thought about all the "up" facing surfaces that can cause reflections, and somehow got thinking about the underside of the sunshades. Noticed that Casselberry is not very far North of Melbourne. Can't help wonder if you are a member of the Port Malabar R&P Club? My son is a member there & regularly shoots the F-Class matches. Great club, we spent some time there last November.
Larry Willis: Thank you for the "heads up". Read your post & thought about all the "up" facing surfaces that can cause reflections, and somehow got thinking about the underside of the sunshades. Noticed that Casselberry is not very far North of Melbourne. Can't help wonder if you are a member of the Port Malabar R&P Club? My son is a member there & regularly shoots the F-Class matches. Great club, we spent some time there last November.
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Larry Willis
Guest
fd shuster,
I've been a member at the Malabar Range for about 8 years. I really like their 600 yard range, but I haven't been there in quite a while. The rule mongers down there are always making it too time consuming to "re-qualify", and it's only possible to get it done on one particular day of each month.
Most of my shooting is done at the range in Geneva or on private land.
- Innovative
I've been a member at the Malabar Range for about 8 years. I really like their 600 yard range, but I haven't been there in quite a while. The rule mongers down there are always making it too time consuming to "re-qualify", and it's only possible to get it done on one particular day of each month.
Most of my shooting is done at the range in Geneva or on private land.
- Innovative
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USSR
Guest
With a Chrony, it is extremely important to protect the sensors from any direct sunlight. Failure to do this will result in false velocity readings of 100-150fps higher than actual. The diffusers alone will not do this. What I do is tape a large target or other piece of translucent material between the two diffusers.
Don
Don
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Larry Willis
Guest
The skyscreens act as "start/stop" switches. A blue sky doesn't affect the accuracy of chronograph readings.
A higher contrast view of your bullet shadow will increase the reliability of a chronograph to detect bullets. A bright sky might not be able to detect your bullet. If it is detected at all, the chronograph accuracy will only be affected by something related to "extra" reflections, shadows, shock waves, vibrations or something that affects the clock in the unit.
- Innovative
A higher contrast view of your bullet shadow will increase the reliability of a chronograph to detect bullets. A bright sky might not be able to detect your bullet. If it is detected at all, the chronograph accuracy will only be affected by something related to "extra" reflections, shadows, shock waves, vibrations or something that affects the clock in the unit.
- Innovative
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Donald
Guest
I have found that when the sun is coming in at a rather low angle, especially in winter, I keep getting error readings. Since my chrony is mounted on a camera tripod, I just tip the chron over until it looks like the sun is coming in directly overhead. Problem solved.