digital noise and image size with *ist D
Posted 15/07/2004 - 15:34
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First, how much noise is too much? I've taken pics at 800 ASA which are not very noisy. I'm using Photoshop CS for the conversion (the plugin is marvelous and you can do colour noise reduction as well as luminance smoothing). I couldn't say that I would see any (excessive) noise after the conversion from RAW files.
As for the size. Yes, 3008 x 2008 is the highest resolution (since it is the native resolution of the detector chip of the *istD). I've ordered A2 prints and found them to be brilliant. I ordered at photobox in the UK. They print at 254 dpi, so I increased the resolution in Photoshop (stepwise at 5 - 10%) to the print resolution (5939 x 4200 for A2). This does not increase the noise. Certainly on one of the pictures that I took at 400 ASA and enlarged to A2 there is some noise discernible if you get really close, but I find it quite acceptable.
If you go to http://www.photoboxgallery.com/Prieni look at the Hawaii collection. I've printed 'Devastation trail' and 'Hawaii volcanoe' in A2. The volcanoe picture was taken at 400 ASA. Both of the pictures were taken in JPEG mode, using RAW mode you have even better possibilities to adjust the pictures when importing to Photoshop.
I haven't tried much with slow shutter speeds and higher ASA. If I need long exposures I have to use a tripod anyway and thus can afford even slower shutter speeds at 200 ASA. Oh, just remembered, I'm lying here: Inadvertently I used 800 ASA at a series of night shots. One of them is
http://home.fotocommunity.de/prieni/index.php?id=419896&d=1465635
which was taken at 1/4s, A 8.0. It didn't seem noisy to me, though. Only problem was that I had a bit of a halo around the 'John Lewis' sign, so I had to patch it up in Photoshop (you can see a black rectangle behind the sign, that's where I did the patch up). If you like I can prepare some 100% cuttings and send them via email.
Hope this helps,
Prieni
As for the size. Yes, 3008 x 2008 is the highest resolution (since it is the native resolution of the detector chip of the *istD). I've ordered A2 prints and found them to be brilliant. I ordered at photobox in the UK. They print at 254 dpi, so I increased the resolution in Photoshop (stepwise at 5 - 10%) to the print resolution (5939 x 4200 for A2). This does not increase the noise. Certainly on one of the pictures that I took at 400 ASA and enlarged to A2 there is some noise discernible if you get really close, but I find it quite acceptable.
If you go to http://www.photoboxgallery.com/Prieni look at the Hawaii collection. I've printed 'Devastation trail' and 'Hawaii volcanoe' in A2. The volcanoe picture was taken at 400 ASA. Both of the pictures were taken in JPEG mode, using RAW mode you have even better possibilities to adjust the pictures when importing to Photoshop.
I haven't tried much with slow shutter speeds and higher ASA. If I need long exposures I have to use a tripod anyway and thus can afford even slower shutter speeds at 200 ASA. Oh, just remembered, I'm lying here: Inadvertently I used 800 ASA at a series of night shots. One of them is
http://home.fotocommunity.de/prieni/index.php?id=419896&d=1465635
which was taken at 1/4s, A 8.0. It didn't seem noisy to me, though. Only problem was that I had a bit of a halo around the 'John Lewis' sign, so I had to patch it up in Photoshop (you can see a black rectangle behind the sign, that's where I did the patch up). If you like I can prepare some 100% cuttings and send them via email.
Hope this helps,
Prieni
Posted 16/07/2004 - 10:20
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Thanks Prieni, I was not aware of photoshop download. Guess this is available from adobe site?
With grain and slow shutter speed, I have been using tripod and still noticeable. Like u I have used 800asa and like this for images and the grain or noise isn't noticeable on the images I used it on.
Regarding the noticeable grain at 400 dpi, it seems to be very visible on seascape 1/20th sec at f22 which was set and slowed on purpose to create slow waves appearance, etc. This could not be enlarged beyond 8x12 as it began to break up too much. Perhaps there was something I did not have right with the settings? I am pretty new with the use of this camera.
Realised that I did not have the setting right for the white balance. Not sure what it was on, but think perhaps sun, which may have been a factor? Am still figuring out its use.
With grain and slow shutter speed, I have been using tripod and still noticeable. Like u I have used 800asa and like this for images and the grain or noise isn't noticeable on the images I used it on.
Regarding the noticeable grain at 400 dpi, it seems to be very visible on seascape 1/20th sec at f22 which was set and slowed on purpose to create slow waves appearance, etc. This could not be enlarged beyond 8x12 as it began to break up too much. Perhaps there was something I did not have right with the settings? I am pretty new with the use of this camera.
Realised that I did not have the setting right for the white balance. Not sure what it was on, but think perhaps sun, which may have been a factor? Am still figuring out its use.
Posted 16/07/2004 - 10:50
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Yes, the plugin for Photoshop CS (unfortunately not suitable for earlier versions of Photoshop) can be downloaded from Adobe.
I can't imagine that the white balance setting should be responsible for getting noise. (If you use the Photoshop plugin and shoot in RAW mode you can change the WB; but that can be done with the Pentax software as well if I remember correctly; haven't touched it since I got the PS plugin).
For the shots that you have taken already it might be worth trying NeatImage on them. MattMatic has done some noise profiles of the *istD and different ISO settings. You can download them from neatimage.com
Might be worthwile to do a comparison with slow shutter speeds and different ISO settings.
Cheers,
Prieni
I can't imagine that the white balance setting should be responsible for getting noise. (If you use the Photoshop plugin and shoot in RAW mode you can change the WB; but that can be done with the Pentax software as well if I remember correctly; haven't touched it since I got the PS plugin).
For the shots that you have taken already it might be worth trying NeatImage on them. MattMatic has done some noise profiles of the *istD and different ISO settings. You can download them from neatimage.com
Might be worthwile to do a comparison with slow shutter speeds and different ISO settings.
Cheers,
Prieni
Posted 16/07/2004 - 12:00
Link
thanks again Prieni,
I have managed to find neat image. Not heard of it before and have purchased a licence, guess will hear shortly. Have also downloaded profiles, there were a few different versions. Not sure what is meant by profiles & which version I would need, so downloaded all of them. Assume they are used in conjunction with neatimage so will wait until I get the download instructions etc to acquire the neat image program.
Sure is a different learning curve but it is fun as well.
One question, shooting in raw or tiff, with the 3008x2008 pixels, is the dpi still 72 in the original camera image or is it larger? Will have to take some on these settings just to look I guess. Bit dark here now and raining so maybe tomorrow. Have been a bit worried about the raw factor cause I thought it might be too complicated for me. Also can't fit as many on the card. 256mg.
Have CS ps and like u haven't looked at pentax software since arrived.
Guess these are silly questions, but appreciate the assistance.
Cheers - Anne
I have managed to find neat image. Not heard of it before and have purchased a licence, guess will hear shortly. Have also downloaded profiles, there were a few different versions. Not sure what is meant by profiles & which version I would need, so downloaded all of them. Assume they are used in conjunction with neatimage so will wait until I get the download instructions etc to acquire the neat image program.
Sure is a different learning curve but it is fun as well.
One question, shooting in raw or tiff, with the 3008x2008 pixels, is the dpi still 72 in the original camera image or is it larger? Will have to take some on these settings just to look I guess. Bit dark here now and raining so maybe tomorrow. Have been a bit worried about the raw factor cause I thought it might be too complicated for me. Also can't fit as many on the card. 256mg.
Have CS ps and like u haven't looked at pentax software since arrived.
Guess these are silly questions, but appreciate the assistance.
Cheers - Anne
Posted 16/07/2004 - 12:15
Link
Hi anneoc,
you can download from NeatImage directly (just did a download of the NeatImage Demo setup for the 4 version, which I didn't try so far). I didn't buy it although I think you can produce files other than JPG with a licenced version. The Pentax profiles are for JPG*** and TIF settings (NeatImage doesn't read RAW directly). The profiles are for different ISO settings and you can do your own profiles. Yes, it's a bit of a learning curve and you can produce very good results as well as rubbish easily with this program.
Concerning the dpi setting, it's not really important. You always can change that in Photoshop (without altering the resolution of the picture; if you change from 72 dpi to 300 dpi it puts about 4 times the resolution in the dialogue boxes; just set them back to 3008 x 2008 again). I think you also can set the dpi in the RAW import plugin of Photoshop.
You're right with the space on the card, PEF (i.e. raw) images have about 13-14 megs so on my 1 GB drive I get about 72 pictures. On holiday trips I have used JPG so far but I think in the long run I will get an image tank to download the pics and free up the flash drive again. Once you get used to using PEF you don't want to go back, it gives you a lot of freedom and it's amazing what you can get out of pictures that are not correct exposed.
Shooting in TIF is a bit pointless, I think. The resulting files are even bigger than PEF files and you can't change exposure and WB any more.
Best of luck with Neat,
Prieni
you can download from NeatImage directly (just did a download of the NeatImage Demo setup for the 4 version, which I didn't try so far). I didn't buy it although I think you can produce files other than JPG with a licenced version. The Pentax profiles are for JPG*** and TIF settings (NeatImage doesn't read RAW directly). The profiles are for different ISO settings and you can do your own profiles. Yes, it's a bit of a learning curve and you can produce very good results as well as rubbish easily with this program.
Concerning the dpi setting, it's not really important. You always can change that in Photoshop (without altering the resolution of the picture; if you change from 72 dpi to 300 dpi it puts about 4 times the resolution in the dialogue boxes; just set them back to 3008 x 2008 again). I think you also can set the dpi in the RAW import plugin of Photoshop.
You're right with the space on the card, PEF (i.e. raw) images have about 13-14 megs so on my 1 GB drive I get about 72 pictures. On holiday trips I have used JPG so far but I think in the long run I will get an image tank to download the pics and free up the flash drive again. Once you get used to using PEF you don't want to go back, it gives you a lot of freedom and it's amazing what you can get out of pictures that are not correct exposed.
Shooting in TIF is a bit pointless, I think. The resulting files are even bigger than PEF files and you can't change exposure and WB any more.
Best of luck with Neat,
Prieni
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6 posts
22 years
Tasmania
Also finding image size 3008x2008 pixels converted to 300dpi from 72 dpi does not enlarge to above A4 without loss of clarity and added noise with all shutter speeds. The 3008 and 2008 pixels seem to be the largest available and, if using print size of 300 dpi, it only enlarges to less than A4. How do u get A3 images with no problems. I have only been using jpg full size so far and haven't tried raw but pixel size seems to be the same.