Re: [pinhole-discussion] increased sharpness?
thanks G! paper film average wavelengths for sensitivity seem to fall in the range of 475 to 500 nm, which is blue-green... it doesn't look like any appreciable difference would show up if they were to be inserted in the optimal diameter formulas because it's so close to green (the wavelength of green light is 525 nm) jim k ---BeginMessage--- - Original Message - From: Jim Kosinski mer...@paintcancamera.com it makes any difference... does anyone know the range of wavelengths that bw paper is sensitive to? Both Ilford and Kodak have spectral sensitivity curves for their papers in their respective sites. Guillermo ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ---End Message---
Re: [pinhole-discussion] increased sharpness?
- Original Message - From: Jim Kosinski mer...@paintcancamera.com it makes any difference... does anyone know the range of wavelengths that bw paper is sensitive to? Both Ilford and Kodak have spectral sensitivity curves for their papers in their respective sites. Guillermo
Re: [pinhole-discussion] increased sharpness?
Yes they have both the Hoyas and the Shott listed under commercial quality bandpass filters in their industrial catalog. They are unmounted which is not a problem for pinhole or zoneplate. Howard Wells Andy Schmitt wrote: I've been looking for one for a while. The optical UV filters are real expensive (+100$). Does Edmunds have the optical grade UV filters at a decent price? thanks andy -Original Message- From: pinhole-discussion-admin@p at ??? [mailto:pinhole-discussion-admin@p at ???]On Behalf Of Howard Wells Sent: Saturday, June 01, 2002 10:46 AM To: pinhole-discussion@p at ??? Subject: Re: [pinhole-discussion] increased sharpness? http://www.naturfotograf.com/index2_PC.html See the link above for a suggestion that exposing pinhole with nothing but UV makes a sharper photo. I've been thinking about buying one of the appropriate filters from Edmund Scientific and trying UV pinhole this summer. Has anyone done it? Howard Wells G.Penate wrote: - Original Message - From: Jim Kosinski mer...@paintcancamera.com in the formulas used to determine the optimal pinhole diameter for a given focal distance the wavelength of green light seems to be used because it's in the center of the visible spectrum... would it be possible to get more sharpness with the same pinhole diameter by changing the color of the light? for example, what if you used a blue bulb to illuminate the subject or put a color filter over the pinhole? (assuming black white film/paper) Yes to all the ??? above. Would you really see a markedly difference in the results? Not quite sure. Guillermo ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
Re: [pinhole-discussion] increased sharpness?
just checked out the link, but that uv pinhole photo is not unusually sharp... i think he just had a decent pinhole to start with the next thought on sharpness is to recalculate the optimum aperture size formula by substituting the average wavelength that paper is actually sensitive to in order to find out if it makes any difference... does anyone know the range of wavelengths that bw paper is sensitive to? jim k ---BeginMessage--- http://www.naturfotograf.com/index2_PC.html See the link above for a suggestion that exposing pinhole with nothing but UV makes a sharper photo. I've been thinking about buying one of the appropriate filters from Edmund Scientific and trying UV pinhole this summer. Has anyone done it? Howard Wells G.Penate wrote: - Original Message - From: Jim Kosinski mer...@paintcancamera.com in the formulas used to determine the optimal pinhole diameter for a given focal distance the wavelength of green light seems to be used because it's in the center of the visible spectrum... would it be possible to get more sharpness with the same pinhole diameter by changing the color of the light? for example, what if you used a blue bulb to illuminate the subject or put a color filter over the pinhole? (assuming black white film/paper) Yes to all the ??? above. Would you really see a markedly difference in the results? Not quite sure. Guillermo ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ---End Message---
RE: [pinhole-discussion] increased sharpness?
I've been looking for one for a while. The optical UV filters are real expensive (+100$). Does Edmunds have the optical grade UV filters at a decent price? thanks andy -Original Message- From: pinhole-discussion-admin@p at ??? [mailto:pinhole-discussion-admin@p at ???]On Behalf Of Howard Wells Sent: Saturday, June 01, 2002 10:46 AM To: pinhole-discussion@p at ??? Subject: Re: [pinhole-discussion] increased sharpness? http://www.naturfotograf.com/index2_PC.html See the link above for a suggestion that exposing pinhole with nothing but UV makes a sharper photo. I've been thinking about buying one of the appropriate filters from Edmund Scientific and trying UV pinhole this summer. Has anyone done it? Howard Wells G.Penate wrote: - Original Message - From: Jim Kosinski mer...@paintcancamera.com in the formulas used to determine the optimal pinhole diameter for a given focal distance the wavelength of green light seems to be used because it's in the center of the visible spectrum... would it be possible to get more sharpness with the same pinhole diameter by changing the color of the light? for example, what if you used a blue bulb to illuminate the subject or put a color filter over the pinhole? (assuming black white film/paper) Yes to all the ??? above. Would you really see a markedly difference in the results? Not quite sure. Guillermo ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
Re: [pinhole-discussion] increased sharpness?
http://www.naturfotograf.com/index2_PC.html See the link above for a suggestion that exposing pinhole with nothing but UV makes a sharper photo. I've been thinking about buying one of the appropriate filters from Edmund Scientific and trying UV pinhole this summer. Has anyone done it? Howard Wells G.Penate wrote: - Original Message - From: Jim Kosinski mer...@paintcancamera.com in the formulas used to determine the optimal pinhole diameter for a given focal distance the wavelength of green light seems to be used because it's in the center of the visible spectrum... would it be possible to get more sharpness with the same pinhole diameter by changing the color of the light? for example, what if you used a blue bulb to illuminate the subject or put a color filter over the pinhole? (assuming black white film/paper) Yes to all the ??? above. Would you really see a markedly difference in the results? Not quite sure. Guillermo ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
