Bulb mode and Lightning Photography

**interested_observer** · 10-05-2010, 06:13 AM

Back on your original question. A couple of nights ago I too was out photographing lightening. I was in several of the modes at ISO 100 and then turned to B, took a image, fortunately checking it and saw the graininess in a very semi daylight image. The ISO was at 3200. I had forgot that the K20 has iso associated with different modes.

I don't have an *ist, but I would check the iso speed associated with the Bulb mode and set it to where you want it.

**Lowell Goudge** · 10-05-2010, 06:35 AM

Originally posted by interested_observer

Back on your original question. A couple of nights ago I too was out photographing lightening. I was in several of the modes at ISO 100 and then turned to B, took a image, fortunately checking it and saw the graininess in a very semi daylight image. The ISO was at 3200. I had forgot that the K20 has iso associated with different modes.

I don't have an *ist, but I would check the iso speed associated with the Bulb mode and set it to where you want it.

*istD does not have ISO modes, ISO is set once for all modes.

I know what you mean with later cameras, K10D can have at least 3 different ISO settings as a function of mode used. Manual is one, User is a second, and you can have the auto modes set to Auto ISO. I have not looked to see if Bulb has an independant setting of its own on the K10D.

**interested_observer** · 10-05-2010, 09:53 PM

I had actually forgotten about this, as I essentially had everything set to 100. The K20 was repaired (new electronics and sensor), so as I use it, I am finding that things need to be setup again.

kari · 10-06-2010, 01:23 AM

As an electronic engineer I find this thread very interesting. I would couple the photodiode to a IR bulb and use that to take the picture (though you'll probably need a PLC too), rather than take the shutter button apart if your camera doesn't have a wired shutter release. I also wonder if you won't maybe get a stronger current from small solar panel than a single photodiode.

**Lowell Goudge** · 10-06-2010, 02:22 AM

Originally posted by kari

As an electronic engineer I find this thread very interesting. I would couple the photodiode to a IR bulb and use that to take the picture (though you'll probably need a PLC too), rather than take the shutter button apart if your camera doesn't have a wired shutter release. I also wonder if you won't maybe get a stronger current from small solar panel than a single photodiode.

There is no need to "take anything apart" all pentax DSLRs have a wired release using a 2mm 3 connection headphone plug. The reason for using a photo diode is because there is no need to supply current, the camera's shutter release circuit does this by way of a resistor in series with the release contact. It is looking for a short to the common to trip the shutter. As for functionality the scheme works and using a commercial plash slave (schematic shown above) it os possible to trip the shutter with a camera flash. To create a lightning trigger simply requires changing the base emitter resistor to reduce the current necessary to turn on the transistor i.e. To increase the sensitivity. Too many people are looking for a complex solution when using these three simple components is all that is needed

akanarya · 10-06-2010, 03:56 AM

Originally posted by Lowell Goudge

all pentax DSLRs have a wired release using a 2mm 3 connection headphone plug

please forgive my ignorancy.
does k-x has??

kari · 10-06-2010, 04:40 AM

Originally posted by akanarya

please forgive my ignorancy.
does k-x has??

No, mine doesn't. I don't think the K-m or the K-r has it either.

bdery · 10-06-2010, 05:03 AM

Digitalis, that picture should be in PPG if it isn't!

Regarding the original question, my technique has been to expose for 30 seconds, allow the K20D to substract noise (weak filter). I used the FA 50 macro, with a polarizer and an ND filter stacked so I could use a decently wide aperture and avoid seeing the window behind which I was standing. Got through in the PPG with that one:

akanarya · 10-06-2010, 11:22 PM

Originally posted by bdery

Digitalis, that picture should be in PPG if it isn't!

Regarding the original question, my technique has been to expose for 30 seconds, allow the K20D to substract noise (weak filter). I used the FA 50 macro, with a polarizer and an ND filter stacked so I could use a decently wide aperture and avoid seeing the window behind which I was standing. Got through in the PPG with that one:

was it a daylight shot?

Stringmike · 10-07-2010, 12:20 PM - **1 Like**

Another technique to photograph lightning in the daytime is to use a filter. Years ago, I used an automated 35mm film camera with a 180-degree fish-eye and an infrared filter as part of a lightning investigation on power lines. Lightning has very strong light emissions in the infrared spectrum (especially hydrogen-alpha). I currently use an inexpensive infra-red filter that enables 15 to 30-second daylight shots.

Triggers that use the electric field change from lightning are preferable to optical triggers if you want to capture the early part of a flash (all those pretty branches!). The optical triggers work fine, but you'll generally only capture subsequent strokes in a multi-stroke flash. Good for engineers, but not so good for artists!

Mike

(who plays with lightning for a living)

**Digitalis** · 10-07-2010, 04:09 PM

that image was not taken during daylight hours.

**Ex Finn.** · 10-07-2010, 04:56 PM

Originally posted by Stringmike

Triggers that use the electric field change from lightning are preferable to optical triggers if you want to capture the early part of a flash (all those pretty branches!). The optical triggers work fine, but you'll generally only capture subsequent strokes in a multi-stroke flash. Good for engineers, but not so good for artists!

Can you elaborate on the E-field triggers?.
I mean, can you educate us on the E-field triggers?.

**Lowell Goudge** · 10-07-2010, 05:21 PM

If you want to trigger from the electric field the easy way is to look for static pulses on the AM radio band and feed the speaker or earphone to the transistor in the flash trigger circuit. The problem I see is being too sensitive. You will trigger on static fromiles away. You are better triggering on what you can see not what the radio can pick up. But I agree you may be able to trigger during the stepped leader process before the complete formation of the ionized channel and the main stroke. I will need to think about this

**Ex Finn.** · 10-07-2010, 05:40 PM

I agree on static messing things up.
Was not really thinking about an AM radio as a trigger device. Your next electric pole with a leaky insulator will set that off, hardly useful as a lightning trigger.

**Ex Finn.** · 10-07-2010, 05:51 PM

Getting back to real E-field detectors, as those that count lightning strikes as sen on The Weather Channel. Again , how much delay?.

10-07-2010, 12:20 PM - 1 Like	#40
Stringmike Senior Member Join Date: Jul 2008 Location: Arizona Posts: 283	Daylight Filter Another technique to photograph lightning in the daytime is to use a filter. Years ago, I used an automated 35mm film camera with a 180-degree fish-eye and an infrared filter as part of a lightning investigation on power lines. Lightning has very strong light emissions in the infrared spectrum (especially hydrogen-alpha). I currently use an inexpensive infra-red filter that enables 15 to 30-second daylight shots. Triggers that use the electric field change from lightning are preferable to optical triggers if you want to capture the early part of a flash (all those pretty branches!). The optical triggers work fine, but you'll generally only capture subsequent strokes in a multi-stroke flash. Good for engineers, but not so good for artists! Mike (who plays with lightning for a living)

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10-05-2010, 06:13 AM	#31
interested_observer Loyal Site Supporter Join Date: Jun 2009 Location: Tumbleweed, Arizona Photos: Gallery \| Albums Posts: 5,707	Back on your original question. A couple of nights ago I too was out photographing lightening. I was in several of the modes at ISO 100 and then turned to B, took a image, fortunately checking it and saw the graininess in a very semi daylight image. The ISO was at 3200. I had forgot that the K20 has iso associated with different modes. I don't have an *ist, but I would check the iso speed associated with the Bulb mode and set it to where you want it.

10-05-2010, 06:35 AM	#32
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,891	Originally posted by interested_observer Back on your original question. A couple of nights ago I too was out photographing lightening. I was in several of the modes at ISO 100 and then turned to B, took a image, fortunately checking it and saw the graininess in a very semi daylight image. The ISO was at 3200. I had forgot that the K20 has iso associated with different modes. I don't have an ist, but I would check the iso speed associated with the Bulb mode and set it to where you want it. istD does not have ISO modes, ISO is set once for all modes. I know what you mean with later cameras, K10D can have at least 3 different ISO settings as a function of mode used. Manual is one, User is a second, and you can have the auto modes set to Auto ISO. I have not looked to see if Bulb has an independant setting of its own on the K10D.

10-05-2010, 09:53 PM	#33
interested_observer Loyal Site Supporter Join Date: Jun 2009 Location: Tumbleweed, Arizona Photos: Gallery \| Albums Posts: 5,707	I had actually forgotten about this, as I essentially had everything set to 100. The K20 was repaired (new electronics and sensor), so as I use it, I am finding that things need to be setup again.

10-06-2010, 01:23 AM	#34
kari Senior Member Join Date: Feb 2010 Photos: Albums Posts: 142	As an electronic engineer I find this thread very interesting. I would couple the photodiode to a IR bulb and use that to take the picture (though you'll probably need a PLC too), rather than take the shutter button apart if your camera doesn't have a wired shutter release. I also wonder if you won't maybe get a stronger current from small solar panel than a single photodiode.

10-06-2010, 02:22 AM	#35
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,891	Originally posted by kari As an electronic engineer I find this thread very interesting. I would couple the photodiode to a IR bulb and use that to take the picture (though you'll probably need a PLC too), rather than take the shutter button apart if your camera doesn't have a wired shutter release. I also wonder if you won't maybe get a stronger current from small solar panel than a single photodiode. There is no need to "take anything apart" all pentax DSLRs have a wired release using a 2mm 3 connection headphone plug. The reason for using a photo diode is because there is no need to supply current, the camera's shutter release circuit does this by way of a resistor in series with the release contact. It is looking for a short to the common to trip the shutter. As for functionality the scheme works and using a commercial plash slave (schematic shown above) it os possible to trip the shutter with a camera flash. To create a lightning trigger simply requires changing the base emitter resistor to reduce the current necessary to turn on the transistor i.e. To increase the sensitivity. Too many people are looking for a complex solution when using these three simple components is all that is needed

10-06-2010, 03:56 AM	#36
akanarya Senior Member Join Date: Aug 2010 Location: Çankırı, Turkey Posts: 210	Originally posted by Lowell Goudge all pentax DSLRs have a wired release using a 2mm 3 connection headphone plug please forgive my ignorancy. does k-x has??

10-06-2010, 04:40 AM	#37
kari Senior Member Join Date: Feb 2010 Photos: Albums Posts: 142	Originally posted by akanarya please forgive my ignorancy. does k-x has?? No, mine doesn't. I don't think the K-m or the K-r has it either.

10-06-2010, 05:03 AM	#38
bdery Pentaxian Join Date: Mar 2008 Location: Quebec city, Canada Photos: Gallery Posts: 9,362	Digitalis, that picture should be in PPG if it isn't! Regarding the original question, my technique has been to expose for 30 seconds, allow the K20D to substract noise (weak filter). I used the FA 50 macro, with a polarizer and an ND filter stacked so I could use a decently wide aperture and avoid seeing the window behind which I was standing. Got through in the PPG with that one:

10-06-2010, 11:22 PM	#39
akanarya Senior Member Join Date: Aug 2010 Location: Çankırı, Turkey Posts: 210	Originally posted by bdery Digitalis, that picture should be in PPG if it isn't! Regarding the original question, my technique has been to expose for 30 seconds, allow the K20D to substract noise (weak filter). I used the FA 50 macro, with a polarizer and an ND filter stacked so I could use a decently wide aperture and avoid seeing the window behind which I was standing. Got through in the PPG with that one: was it a daylight shot?

10-07-2010, 04:09 PM	#41
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	that image was not taken during daylight hours.

10-07-2010, 04:56 PM	#42
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Originally posted by Stringmike Triggers that use the electric field change from lightning are preferable to optical triggers if you want to capture the early part of a flash (all those pretty branches!). The optical triggers work fine, but you'll generally only capture subsequent strokes in a multi-stroke flash. Good for engineers, but not so good for artists! Can you elaborate on the E-field triggers?. I mean, can you educate us on the E-field triggers?.

10-07-2010, 05:21 PM	#43
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,891	If you want to trigger from the electric field the easy way is to look for static pulses on the AM radio band and feed the speaker or earphone to the transistor in the flash trigger circuit. The problem I see is being too sensitive. You will trigger on static fromiles away. You are better triggering on what you can see not what the radio can pick up. But I agree you may be able to trigger during the stepped leader process before the complete formation of the ionized channel and the main stroke. I will need to think about this

10-07-2010, 05:40 PM	#44
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	I agree on static messing things up. Was not really thinking about an AM radio as a trigger device. Your next electric pole with a leaky insulator will set that off, hardly useful as a lightning trigger.

10-07-2010, 05:51 PM	#45
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	Getting back to real E-field detectors, as those that count lightning strikes as sen on The Weather Channel. Again , how much delay?.