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Old Mar 12, 2009, 5:52 AM   #1
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Hi guys..

took the new toy out playing today got bored with the 18-50 as there wasnt much to see so started playing with the 70-300 on macro... im very impressed!

i ws just toying with the settings and different modes.. to get a feel for how everything interacts. Im amazed just how much light is required to get the shutter speed up!

all pictures are hand held and at 200+mm.. will add details with each photo..

here we go....

Model:PENTAX K20D
ISO:200
Exposure:1/180 sec
Aperture:5.6
Focal Length:300mm - macro on



Model:PENTAX K20D
ISO:560
Exposure:1/250 sec
Aperture:5.6
Focal Length:240mm



Model:PENTAX K20D
ISO:100
Exposure:1/350 sec
Aperture:6.7
Focal Length:300mm - Macro on



Model:PENTAX K20D
ISO:100
Exposure:1/350 sec
Aperture:5.6
Focal Length:210mm - macro on



Model:PENTAX K20D
ISO:200
Exposure:1/125 sec
Aperture:5.6
Focal Length:300mm - macro on



and finally a crop of the above...




enjoy!

Steve
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Old Mar 12, 2009, 7:06 AM   #2
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Really good for a first go at it Steve. What ISO do you have the camera set on? A higher ISO will allow for a faster shutter speed ,a higher f/stop number and a resulting Wider DOF. This will aid in getting less vibration thus sharper images and a deeper focus field thus more of the image will be in focus. That lens should do well at f/8-f/9.5. Just a suggestion and I do mean these are pretty darn good as is. You'll get lots of advice...try them all then settle in on what you want or like.

Dawg
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Old Mar 12, 2009, 12:41 PM   #3
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Looks like you're having a ton of fun Steve!
GW:bye:
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Old Mar 12, 2009, 6:43 PM   #4
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bigdawg wrote:
Quote:
Really good for a first go at it Steve. What ISO do you have the camera set on? A higher ISO will allow for a faster shutter speed ,a higher f/stop number and a resulting Wider DOF. This will aid in getting less vibration thus sharper images and a deeper focus field thus more of the image will be in focus. That lens should do well at f/8-f/9.5. Just a suggestion and I do mean these are pretty darn good as is. You'll get lots of advice...try them all then settle in on what you want or like.

Dawg
Thanks Dawg.. appreciate the hints :G the Iso is shown just above each picture... and i think i had fixed it or was adjusting it to minimise the noise, probably a throwback from my old camera that had noise at iso200! again... its a learning curve:?. What realistically is the highest iso i should be looking for without having to do too much noise reduction?

one of the reasons i was setting the aperture to a low number (is that open or closed? i cant remember!) is that i love very shallow DOF and the way the picture looks with it.. i think i may be a bit strange in this regard.. i think i have some others that had a higher f/stop and therefore more focused.

one thing i have noticed which took be by surprise (probably me being dumb) is that the larger the aperture the slower the shutter speed.. i had it in my head that it ws the other way round ... again a throw back from having a camera doing most things for you i guess.. Is there any good reading you guys can suggest on the manual use of cameras (or just a good DSLR guide?)

Ultimately tho... im very impressed with the sigmas pictures as it really is a cheap lens.. im not so happy with the 18-50 at the moment tho.. as i dont think its focussing right. i had a play with the focus21.pdf focus chart and the focus adjust last night and the lens seems to require some adjustment... just haven't had long enough to play yet... :roll:

Quote:
Looks like you're having a ton of fun Steve! GW:bye:
Thanks GW.. I am! its a bit daunting tho wondering what to do with all these buttons! :lol:

Thanks guys.. andy more hints will be greatly appreciated!

Steve

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Old Mar 12, 2009, 8:24 PM   #5
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Looks like you're having a blast, Steve. I know what you mean about learning all the buttons. I'm still trying to learn them all.

Patty
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Old Mar 12, 2009, 8:26 PM   #6
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Hi Steve. Sorry for missing the ISO but I was at work last night and half asleep when I wrote that. I use the computer and the forums to stay awake during the long night shifts. I use ISO 400 with nearly zero noise and ISO 800 and 1100 but in post processing I use the noise reduction program Neat Image to remove the noise. Not that at ISO 800 is that bad at all but when you crop a photo to enlarge the image you also enlarge the pixels thus the noise is more apparent. You can get a free Demo copy of neat image at...
http://www.neatimage.com/download.html

You could call the relationship of shutter speed to f/stop as an inverse proportion...The higher the f/stop number the slower the shutter speed. The lower the f/stop number the faster the shutter speed. At least that is how I tend to remember it. You already know this I'm sure but anyway ...A higher f/stop number means the aperture closes to a smaller opening and for each number you go higher you get 1/2 of the light the lower number was giving you. Thus the shutter must stay open a proportional amount longer to allow enough light for a proper exposure. In auto the camera does all this for you and a large part of the time it does an excellent job. I shoot in Av mode most of the time or in manual when I want to get a lower or higher exposure than the camera's auto setting will allow or in those times the auto exposure routine just can't get it right.

You can go here for a better explanation than mine.

http://lifehacker.com/software/featu...ore-328488.php

For a basic on macros go here...or google one up as there are tons of tutorials out there.

http://www.bmpt1.com/
Hope some of this helps...Gotta run.

Dawg
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Old Mar 13, 2009, 3:05 PM   #7
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Hey Steve,
the best $20 I've spent on photo gear was for a copy of the Magic lantern series guidebooks on the K10, very nice indeed!

GW:bye:
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Old Mar 13, 2009, 7:32 PM   #8
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If you want a good book that's about general photography information, check out Bryan Peterson's Understanding Exposure. He also has a book Understanding Shutter Speed but I'd start with the exposure book first. It does an excellent job of explaining the basics and also gives some ideas of ways to use the principles. The one on shutter speed gives some hints on what shutter speeds to use in specific situations.

P.S. As far as noise - the big thing I find is that I need to "expose" to the right of the histogram (my tendency is to slightly underexpose). Doing that I'll use ISO 1600 and downside without using much (if any) noise reduction. If I have to "push" the picture much, it will increase noise. I've used ISO 2000 with a bit of noise reduction without too much trouble. ISO 3200 is OK if you resize down, but certain colors (pre-dawn blue being one of them) have trouble at this ISO. Forget ISO 6400 unless it's that or you aren't going to get the shot.

For the most part, my camera is set to ISO Auto with 100-1600 as the range.
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Old Mar 13, 2009, 7:37 PM   #9
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5teve wrote:
Quote:
i think i had fixed it or was adjusting it to minimise the noise, probably a throwback from my old camera that had noise at iso200! again... its a learning curve¬*:?.¬* What realistically is the highest iso i should be looking for without having to do too much noise reduction?

one of the reasons i was setting the aperture to a low number (is that open or closed? i cant remember!) is that i love very shallow DOF and the way the picture looks with it.. i think i may be a bit strange in this regard.. i think i have some others that had a higher f/stop and therefore more focused.
Hi Steve,

Each person has their own idea of what's acceptable for noise. With the K20, I find that I can generally use ISO up to 1250 without having to resort to NR programs or processing specifically for noise -- for web posts and prints to about 8x10. For larger prints, I'd probably set my upper limit at about ISO 800, but I PP differently from most. . . I downsize in steps and sharpen in small increments between downsizes. For me, this is the best way to retain detail for posting.

I've found that for web posting where you need to downsize to about 800 pixels on the long side, and you expose properly -- the downsizing pretty much makes the K20's Luminance noise at 1250 irrelevant if you do some of the downsizing before doing any sharpening.

Here's an example of a K20 shot at 1250 resized to @ 800x577 for posting -- sharpened, but no NR used:


Scott
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Old Mar 15, 2009, 10:01 PM   #10
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bigdawg wrote:
Quote:
Hi Steve. Sorry for missing the ISO but I was at work last night and half asleep when I wrote that. I use the computer and the forums to stay awake during the long night shifts. I use ISO 400 with nearly zero noise and ISO 800 and 1100 but in post processing I use the noise reduction program Neat Image to remove the noise. Not that at ISO 800 is that bad at all but when you crop a photo to enlarge the image you also enlarge the pixels thus the noise is more apparent. You can get a free Demo copy of neat image at...
http://www.neatimage.com/download.html

You could call the relationship of shutter speed to f/stop as an inverse proportion...The higher the f/stop number the slower the shutter speed. The lower the f/stop number the faster the shutter speed. At least that is how I tend to remember it. You already know this I'm sure but anyway ...A higher f/stop number means the aperture closes to a smaller opening and for each number you go higher you get 1/2 of the light the lower number was giving you. Thus the shutter must stay open a proportional amount longer to allow enough light for a proper exposure. In auto the camera does all this for you and a large part of the time it does an excellent job. I shoot in Av mode most of the time or in manual when I want to get a lower or higher exposure than the camera's auto setting will allow or in those times the auto exposure routine just can't get it right.

You can go here for a better explanation than mine.

http://lifehacker.com/software/featu...ore-328488.php

For a basic on macros go here...or google one up as there are tons of tutorials out there.

http://www.bmpt1.com/
Hope some of this helps...Gotta run.

Dawg
No prob there Dawg... thought i would point it out tho :? to help your tired eyes! i have used and understand neatimage so i have no issues there with some noise reduction.

i appreciate the info and the links... once i get a second i will look at them and digest them.. as i have with your info.. im a bit busy looking for a new job now which isnt easy in the current market!

Quote:
Hey Steve, the best $20 I've spent on photo gear was for a copy of the Magic lantern series guidebooks on the K10, very nice indeed! GW:bye:
Thanks GW.. i'll have a look around see if its available here.. and put it on the wanted list.. :lol:

Quote:
If you want a good book that's about general photography information, check out Bryan Peterson's Understanding Exposure. He also has a book Understanding Shutter Speed but I'd start with the exposure book first. It does an excellent job of explaining the basics and also gives some ideas of ways to use the principles. The one on shutter speed gives some hints on what shutter speeds to use in specific situations. P.S. As far as noise - the big thing I find is that I need to "expose" to the right of the histogram (my tendency is to slightly underexpose). Doing that I'll use ISO 1600 and downside without using much (if any) noise reduction. If I have to "push" the picture much, it will increase noise. I've used ISO 2000 with a bit of noise reduction without too much trouble. ISO 3200 is OK if you resize down, but certain colors (pre-dawn blue being one of them) have trouble at this ISO. Forget ISO 6400 unless it's that or you aren't going to get the shot. For the most part, my camera is set to ISO Auto with 100-1600 as the range.
Also thankyou to you Mtngal another book that sounds worth adding to the wanted list .. its growing! :-)

i have been using the histogram a little on picture review.. and if its central it seems about right for my tastes.. i did have the iso on auto but i think for the above i set it to reduce noise.. i think it is set at the 100-1600 range too.

Quote:
Hi Steve, Each person has their own idea of what's acceptable for noise. With the K20, I find that I can generally use ISO up to 1250 without having to resort to NR programs or processing specifically for noise -- for web posts and prints to about 8x10. For larger prints, I'd probably set my upper limit at about ISO 800, but I PP differently from most. . . I downsize in steps and sharpen in small increments between downsizes. For me, this is the best way to retain detail for posting. I've found that for web posting where you need to downsize to about 800 pixels on the long side, and you expose properly -- the downsizing pretty much makes the K20's Luminance noise at 1250 irrelevant if you do some of the downsizing before doing any sharpening. Here's an example of a K20 shot at 1250 resized to @ 800x577 for posting -- sharpened, but no NR used: Scott
Thank you Scott for your hints there, and for your steps of downsizing... for webpost i just let picasa upload / reduce to my web albums and then picasa also then downsizes for linked pictures to 800 wide.. sharpness is something i have never played with (i have never felt like i needed to as i can generally see what i think is a grainyness introduced.. bjut we have already established im strange :lol


Again guys many thanks for your info and knowledge.. i have lots to digest and learn.. and hopefully with your continued patience i will progress some more

Thanks

Steve
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