RE: 77 specular bokeh talk (again!)
That's called spherical aberration or coma I think. Unless the aperture diaphragm is not circular at whatever F-stop you chose. Kent Gittings -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Ed Mathews Sent: Saturday, January 05, 2002 5:26 PM To: [EMAIL PROTECTED] Subject: 77 specular bokeh talk (again!) Just when you thought it was safe to go back in the water. A week or so ago there was some limited g discussion about the Nikon 105, it's bokeh, and the 77 bokeh. I mentioned that the 77 yields nice bokeh, with some football (American football) shaped highlights. Nobody commented about that, and probably nobody understood what I meant. So I thought I'd take a picture of my Christmas tree lights out of focus to show you. This is background bokeh, with the brightest lights about 7 feet away, and the lens focused to about 3 feet. In this shot, the lens is at F2.8. In other shots I took at smaller apertures, the highlights of course get smaller, and the football shapes start to get more round. It appears to me that the shape becomes more oblong closer to the edge, and that they kind of look like they circle around the center axis. Tell me what you think. http://lightandsilver.com/Temp/77.htm Thanks, Ed http://lightandsilver.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
RE: 77 specular bokeh talk (again!)
The faster the optical system (or F-stop) the more pronounced the coma can be. Kent Gittings -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Bruce Dayton Sent: Saturday, January 05, 2002 6:40 PM To: Ed Mathews Subject: Re: 77 specular bokeh talk (again!) Ed, It's certainly very visible. This is an area where the FA*85 beats the 77 in my opinion. It produces nice, round highlights. I have thought long and hard about getting the 77 and seeing this makes me want to just keep and use my FA*85 (already paid for). I would be curious to know if this is consistent from sample to sample or is there some variance. Any other 77 owners noticed the highlights to be like Ed's sample here? Bruce Dayton Saturday, January 05, 2002, 2:26:12 PM, you wrote: EM Just when you thought it was safe to go back in the water. A week EM or so ago there was some limited g discussion about the Nikon 105, EM it's bokeh, and the 77 bokeh. I mentioned that the 77 yields nice EM bokeh, with some football (American football) shaped highlights. Nobody EM commented about that, and probably nobody understood what I meant. So I EM thought I'd take a picture of my Christmas tree lights out of focus to EM show you. EM This is background bokeh, with the brightest lights about 7 feet away, EM and the lens focused to about 3 feet. In this shot, the lens is at EM F2.8. In other shots I took at smaller apertures, the highlights of EM course get smaller, and the football shapes start to get more round. EM It appears to me that the shape becomes more oblong closer to the edge, EM and that they kind of look like they circle around the center axis. EM Tell me what you think. EM http://lightandsilver.com/Temp/77.htm EM Thanks, EM Ed - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
RE: 77 specular bokeh talk (again!)
OK Yoshihiko, I'll accept this explanation from you and Dan (mostly because I don't know any better myself and trust others on this). But I do wonder why I have only noticed it with the 43 and the 77. At some point, I would also like to see some sort of illustration showing what spherical aberration looks like, if possible. I've become intrigued by it and way too interested in it for my own good. I'm still considering buying an MZ-S, mainly so I can keep this 77 because I like it so much. As I sell more stuff and actually get the money, that decision might become even more difficult. Thanks, Ed http://lightandsilver.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Yoshihiko Takinami Sent: Sunday, January 06, 2002 5:07 AM To: [EMAIL PROTECTED] Subject: Re: 77 specular bokeh talk (again!) Hi Ed and everyone, SNIP It's not bokeh but just vignetting as Dan wrote. BTW, I was really impressed at the very smooth outlines of the football shapes of out-of-focus background spotlights while you stopped down about one and a half stops. Hope this helps. - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
RE: 77 specular bokeh talk (again!)
On 6 Jan 2002 at 9:42, Ed Mathews wrote: OK Yoshihiko, I'll accept this explanation from you and Dan (mostly because I don't know any better myself and trust others on this). But I do wonder why I have only noticed it with the 43 and the 77. Ed, See http://pug.komkon.org/00marc/tracy.htm same thing but with my 50 f/1.2, a little bit more edgy though. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: 77 specular bokeh talk (again!)
Hi Ed, On 6 Jan 2002 at 06:42:50 -0800 , Ed Mathews wrote: OK Yoshihiko, I'll accept this explanation from you and Dan (mostly because I don't know any better myself and trust others on this). But I do wonder why I have only noticed it with the 43 and the 77. I suppose it would be because they have much vignetting than their counterparts for they were designed to be compact as possible. Think of their sizes !! :^) At some point, I would also like to see some sort of illustration showing what spherical aberration looks like, if possible. Spherical aberration brings some soft, or veiled, images like Pentax soft lenses. You can also see some sort of soft effect by spherical aberration with K50/1.2, or A50/1.2, wide open in the strong daylight. I'm still considering buying an MZ-S, mainly so I can keep this 77 because I like it so much. As I sell more stuff and actually get the money, that decision might become even more difficult. I also do think the 77 Limited is really excellent and I love mine. :^) Regards, -- Yoshihiko Takinami Osaka, Japan [EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: 77 specular bokeh talk (again!)
I've seen these football shaped highlights with my SMC-M 50mm f1.4. -Aaron - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
RE: 77 specular bokeh talk (again!)
Yup. And pretty edgy for sure. Seems you have a lot off bad bokeh luck. :) Thanks, Ed http://lightandsilver.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Rob Studdert Sent: Sunday, January 06, 2002 11:08 AM To: [EMAIL PROTECTED] Subject: RE: 77 specular bokeh talk (again!) snip Ed, See http://pug.komkon.org/00marc/tracy.htm same thing but with my 50 f/1.2, a little bit more edgy though. snip - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
RE: 77 specular bokeh talk (again!)
Hi Kristian, Yes, I saw it with the 43 also, and your photo shows it nicely. And it's a quality I've seen in photos taken with Leica lenses too. It's well discussed that great bokeh has been associated with a degree of spherical aberration, and in fact the 105 F2 DC Nikkor portrait lens actually allows the user to dial in some spherical aberration. Since what we're looking at happens differently off axis, and appears to revolve around the center axis of the lens, I wonder if this is indeed just a picture of spherical aberration? This is probably why the lens exhibits such nice background blur at larger apertures with smooth transitions when there are no real highlights but just more even tones. Is it literally distorting the background and blurring it into the next tone like an artist who would be smearing wet paint? We need a lens guru for this one. Thanks, Ed http://lightandsilver.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Kristian Walsh Sent: Saturday, January 05, 2002 6:13 PM To: [EMAIL PROTECTED] Subject: Re: 77 specular bokeh talk (again!) Hi Ed, I agree, and I've seen this with pictures taken with the 43 too. The only example I have isn't as clear-cut as yours, but if you compare the shape of the spots in the top right to those at the top of the frame in: http://homepage.mac.com/walshk/moira.jpeg ...you might see it. The distortion is very slight, and I only notice the squashing of the highlights with the lens wide open. Once stopped down, it's very difficult to see a difference. Nothing I'm losing sleep over, and far outweighed by the wonderful pictures this lens produces... -- Kristian On Saturday, January 5, 2002, at 10:26 pm, Ed Mathews wrote: Just when you thought it was safe to go back in the water. A week or so ago there was some limited g discussion about the Nikon 105, it's bokeh, and the 77 bokeh. I mentioned that the 77 yields nice bokeh, with some football (American football) shaped highlights. Nobody commented about that, and probably nobody understood what I meant. So I thought I'd take a picture of my Christmas tree lights out of focus to show you. This is background bokeh, with the brightest lights about 7 feet away, and the lens focused to about 3 feet. In this shot, the lens is at F2.8. In other shots I took at smaller apertures, the highlights of course get smaller, and the football shapes start to get more round. It appears to me that the shape becomes more oblong closer to the edge, and that they kind of look like they circle around the center axis. Tell me what you think. http://lightandsilver.com/Temp/77.htm Thanks, Ed http://lightandsilver.com - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: 77 specular bokeh talk (again!)
Yes. Dan Scott [EMAIL PROTECTED] Any other 77 owners noticed the highlights to be like Ed's sample here? Bruce Dayton - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
Re: 77 specular bokeh talk (again!)
Ed Mathews wrote: I mentioned that the 77 yields nice bokeh, with some football (American football) shaped highlights. Nobody commented about that, and probably nobody understood what I meant. So I thought I'd take a picture of my Christmas tree lights out of focus to show you. I think all lenses do it - at least all the ones I've looked at (its less pronounced with longer lenses). My theory is that its caused by an internal vignetting. Look into the lens and swing it around, you won't see a perfect circle through the elements from all angles :) It follows that if I'm right, the effect would diminish when using lenses with a larger image circle. The effect goes away when stopped down, as you've noticed. Cheers, - Dave David A. Mann, B.E. (Elec) Why is it that if an adult behaves like a child they lock him up, while children are allowed to run free on the streets? -- Garfield - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
