Search results for 'uv filter' - page 165
Black and White on istd
The Pentax *istDS has a function that enables files to be saved as monochrome (black and white) or sepia. The original colour file remains. Hopefully an *istD user will tell us if the same is possible. It is probably better to convert the file to monochrome in Photoshop, and my preference for thi...
Posted by johnriley on 15/04/2005 - 14:27
Ist DS and polarising filters
I took some shots with a circular polarising filter attached to my Ist DS at the weekend, and was surprised to find that the results appear to be several stops under exposed. I was using auto landscape metering, and from EXIF was getting approx 1/200 at f11, so light OK. I've never had such a p...
Posted by Ken Barley on 01/06/2005 - 21:09
Digital Infra-Red
I have always enjoyed IR images, and use either Kodak High Speed Infra-Red film or digitally use Channel Mixer as a starting point for pseudo-IR. I would like to explore IR photography using the R72 IR filter, but I wonder if anyone knows exactly how sensitive the *istDS is to IR light? Some manu...
Posted by johnriley on 20/06/2005 - 18:10
Digital Infra-Red
Thanks, Terry, good idea. I've tried it and the *istDS looks promising. Now to get the filter!
Posted by johnriley on 21/06/2005 - 23:01
Digital Infra-Red
John, Here's one from Pete Bargh, taken with the *ist-D and an R72 filter: http://www.ephotozine.com/gallery/showlargepic.cfm?photoid=108185 ;) Matt
Posted by MattMatic on 22/06/2005 - 00:25
Digital Infra-Red
I've now tried the *istDS with the Hoya R72 Infra-red filter, and the results are very good. The ISO needs raising - I used 3200 because grain/noise is not an issue if you want to mimic the effects of film. The only problem is that with the filter fitted, the viewfinder is virtually black! In the...
Posted by johnriley on 10/07/2005 - 12:22
Digital Infra-Red
I have done it using a tripod to frame and focus then add the filter and used exposure bracketing.
Posted by joelw135 on 01/10/2005 - 15:31
Digital Infra-Red
I did likewise, but found it easiest to use a Cokin P007 IR filter which slides in with less chance of accidentally altering the focus. Anyone know of an esay way go get an IR flash? I have tried covering my flash gun with an IR filter sheet from http://www.alanaecology.com/acatalog/Infrared_Fil...
Posted by Ammonyte on 09/11/2005 - 23:43
Digital Infra-Red
I tested my *st D in a dark room with a TV remote. It will see IR light. But to get real IR photos, you need a filter that blocks the visible part of the spctrum.
Posted by Arthur Dent on 14/11/2005 - 14:48
Digital Infra-Red
Most sources on Digital IR photography recomend digicams that let you use the LCD screen as a viewfinder. I have just seen in the Speedgraphic catalogue the Zigview digital anglefinder. Is this sufficiently senstive to IR so that it could be used when an IR filter is in place over the lens? At £...
Posted by Ammonyte on 14/11/2005 - 21:18
Digital Infra-Red
Very interesting thread. A couple of questions: 1) What sort of exposures were required with the R72 filter? 2) Anyone tried a milder filter? I've got a wratten 29 gel which I used to use with IR film so I was thinking about giving that a try.
Posted by niblue on 19/12/2005 - 22:30
Digital Infra-Red
1) It depends on the amount of IR light and how sensitive the CCD is to it. With my Fuji S7000 the exposures run into many seconds and are not that good. With my Pentax *istDS hand holding is possible if the ISO is upped to 1600 or 3200. The results with the *istDS are excellent. 2) You can use a...
Posted by johnriley on 19/12/2005 - 22:38
Digital Infra-Red
niblue, I have posted a couple of samples here http://uk.pg.photos.yahoo.com/ph/ammonyte579. I kept the ISO to 400 as higher values made it granier than I like, which puts exposures into the 1/2 to 5 seconds range. I haven't had much chance to experiment yet, I can't wait for the spring and a lot o...
Posted by Ammonyte on 20/12/2005 - 13:03
Digital Infra-Red
Well I got an R72 filter and initial experimentation looks promising however I've a question about post-processing of the images. At the moment I'm just converting to B&W in photoshop elements but I'd be interesting in what other folks are doing to process the image from the camera.
Posted by niblue on 01/01/2006 - 13:52
Digital Infra-Red
I don't have any experience in shooting through an IR filter, although I've recently acquired one (Hoya R72) to try out later in the Spring. I found some useful info on the following website, which also refers to the processing in Photoshop. http://www.jr-worldwi.de/photo/
Posted by Rowdy on 21/02/2006 - 23:17
Digital Infra-Red
Good question. As most (if not all) modern cameras have auto-focus, can they 'see' infrared? If they can, and one puts an IR filter between subject and lens, thus limiting the light that the AF system 'sees' to being in the IR range of the spectrum, does it focus correctly? I have no idea, do you...
Posted by Mannesty on 20/04/2006 - 21:34
Digital Infra-Red
Truth is, if you can see it, it ain't infrared. The human eye, which is what most of us are equipped with, can't 'see' wavelengths that fall into the infrared part of the light spectrum as it is outside our range of visual sensitivity at wavelengths longer than about 800nm. The red light that y...
Posted by Mannesty on 21/04/2006 - 00:54
Why Raw?
...Pentax's own RAW convertor, like, totally sucks. I wasn't going to put it quite as strongly as that, but now that you mention it!! :D :P The reason is quite simple and is to do with what RAW actually is. RAW isn't "complete", as it were. In the resulting TIFF image, there are three values per ...
Posted by MattMatic on 18/07/2005 - 15:38
UV filters on Digital *istDs
I am new to the forum, so hope I have found the right way to use it. :!: I recently purchased a *istDs body so that I could use the Sigma lenses that I had for my Pentax Mz5N. To protect the lenses I use a UV filter permanently on the front. For film use I did not find this a problem. Howeve...
Posted by Anonymous on 30/08/2005 - 15:30
UV filters on Digital *istDs
The filter shouldn't degrade the image on a digital sensor any more than it does on film. Personally, I try to avoid the use of filters unless I actually need them. I know they help to protect the lens, but they inevitably interfere with the light path, and I would prefer to take care and risk d...
Posted by George Lazarette on 30/08/2005 - 16:06
