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View Full Version : How do you guys trades off Sharp-ness vs Noise


ckckevin
21st of November 2009 (Sat), 16:58
For awhile i've been thinking about this question. how do i trade off sweet spot vs noise for the best picture quality. Especially in a picture that DOF doesn't really matter. As most of the lens the "sweet spot" is about 1 stop from the wide open( i don't want to hear how such and such lens is super sharp at wide open neither.), sometimes, with the given shutter speed, should i step down and crank the iso up, for best picture quality. My general take is that as long as ISO is 800 or less, i'm will to trade for the sharpness and crank up the ISO, any personal opinion, or you guys experience on that?


I just want to hear how you guys would do in that situation, given that extra light is not available. I do day/night landscape/portrait indoor/outdoor.

FlyingPhotog
21st of November 2009 (Sat), 17:00
If sharpness is absolutely key, I'll stay at the f/stop I want and bump the ISO if needed.

Modern cameras are rediculessly clean to very high ISOs so IMO, it's really a no brainer.

If the subject matter allows though, I'll grab a tripod and cable release as the first choice though.

cdifoto
21st of November 2009 (Sat), 17:22
You'll eventually learn to ignore the "sweet spot" and use the aperture, shutter speed, and ISO needed.

JeffreyG
21st of November 2009 (Sat), 17:52
I never think about a lens 'sweet spot' when selecting aperture. DOF is my primary concern, and in low light I also start to worry about adequate shutter speed.

I have chosen lenses that work well wide open, and I don't worry about the difference between 'good enough' and 'really good' that I might get stopping down.

One other thing to keep in mind is that a lot of the time that you are riding the ragged edge between maximum aperture, high ISO and too slow of a shutter speed, lens aberrations are probably going to be the least of the effects softening your photos.

You are unlikely to notice the difference between wide open and stopped down on most lenses unless you are on a sturdy tripod or shooting at a shutter speed 2X to 3X the handholding rule of thumb.

shomat
21st of November 2009 (Sat), 17:56
You'll eventually learn to ignore the "sweet spot" and use the aperture, shutter speed, and ISO needed.

Agreed. I've got my fast primes for a reason and I'm going to make use of them.

Karl Johnston
21st of November 2009 (Sat), 18:13
Get a 5D mark II :D and then never worry about ISO again !

birdfromboat
21st of November 2009 (Sat), 19:00
I am and probably will be continually amazed at the 5d classic ability to shoot higher ISO than I would think 'safe'. I use aperture to get what I want, ISO to make it possible to get a shutter speed I can hand hold or to get a fast enough speed for active subjects.
1-aperture
2-lowest ISO that gives me a shutterspeed I can hand hold
3-or higher yet to get me a fast enough shutter for a moving subject (1/125 or faster)

I have to wonder, how slow a lens is now fast enough to shoot basketball handheld with a 5dmkII set at ISO xxxxxxx? I mean, gee whiz, with a high enough ISO, who needs fast lenses? What happens if you just drill a pinhole in the body cap?

yogestee
21st of November 2009 (Sat), 19:42
I never think about a lens 'sweet spot' when selecting aperture. DOF is my primary concern, and in low light I also start to worry about adequate shutter speed.


The same goes for me.. The current crop of DSLRs are incedibly clean when it comes to noise as opposed to film..

RDKirk
21st of November 2009 (Sat), 22:04
I have to wonder, how slow a lens is now fast enough to shoot basketball handheld with a 5dmkII set at ISO xxxxxxx?

I used to shoot basketball with a Mamiya press camera: f4.5 (the maximum aperture), 1/250, Tri-X at 320 ASA. The hard part was follow-focusing with a double-image rangefinder. I compensated for the shutter speed by learning to shoot for the peak action...which is the most exciting action anyway.

With AI Servo focusing, f4.5 at 1/250 would be nearly cake. But at ISO 1600, gee, at 1/1000 and with AI Servo it would just be too easy.

DStanic
22nd of November 2009 (Sun), 17:05
You'll eventually learn to ignore the "sweet spot" and use the aperture, shutter speed, and ISO needed.

x2

If a lens is really that soft wide open then you should probably have it serviced or sell it and buy something better.

Depending what you are shooting is more important for choosing DOF and ISO.

If I was shooting sports (someone running for example) I would rather crank up the ISO then to shoot at f/1.8 and miss the focus (due to narrow DOF).

Karl Johnston
22nd of November 2009 (Sun), 19:15
Even the 50 1.8 is sharp wide open; it's just the autofocus that completely and utterly blows.

ckckevin
23rd of November 2009 (Mon), 02:51
Thanks you guys! I've just got some good insight to what real photography is like from you guys. I guess knowing the "sweet spot" and being obsesses about it is two different stories, then. I guess being obsesses about it only will cause harm to my photography skills. I guess the true photography spirit is more so on the composition and the message conveyed more so than the absolute sharpness of a picture. right?

ckckevin
23rd of November 2009 (Mon), 03:02
Get a 5D mark II :D and then never worry about ISO again !

I played with my friends 5D2, the noise control is amazing. but i don't think i'll go FF yet, because i still want the reach from the crop for telephotos. The DOF is amazing though, but it's not my top piority yet. i don't think i'll upgrade until for another 2-3 years (although i've probably put somewhat 30,000 shots on my 500D already, so the time may come earlier), but i think the next body will still be a crop.
Now i'm still focusing on my lens set, i think i have amazing set to get stuff done. And all fit inside a small bag, so i'm very happy and content.

ckckevin
23rd of November 2009 (Mon), 03:09
One other thing to keep in mind is that a lot of the time that you are riding the ragged edge between maximum aperture, high ISO and too slow of a shutter speed, lens aberrations are probably going to be the least of the effects softening your photos.

You are unlikely to notice the difference between wide open and stopped down on most lenses unless you are on a sturdy tripod or shooting at a shutter speed 2X to 3X the handholding rule of thumb.

Thanks, Jeffrey. I love your answer. Although i actually can tell the difference b/c i pixel peeps alot, but your answer make sense a lot.

masayako
26th of November 2009 (Thu), 11:48
1. Decide how big a house you want to build (Aperture)
2. Then, decide how many workers you need (More workers = Higher ISO = Higher noises)
3. The result will determine how long the project (photo) takes (Shutter speed)

Notes:
- Sometimes you want to build house slow because you want to ensure quality and make sure certain details are included.
- Sometimes you want to build house fast because you may only be allowed a very short period of time to finish it up

neilwood32
26th of November 2009 (Thu), 11:56
1. Decide how big a house you want to build (Aperture)
2. Then, decide how many workers you need (More workers = Higher ISO = Higher noises)
3. The result will determine how long the project (photo) takes (Shutter speed)

Notes:
- Sometimes you want to build house slow because you want to ensure quality and make sure certain details are included.
- Sometimes you want to build house fast because you may only be allowed a very short period of time to finish it up

I wouldnt sugest this method.

The important items IMHO for any image are the aperture (size of DOF) and shutterspeed (motion blur or lack of).

Example - birds in flight (applies to cars/planes/people etc). Aperture fairly wide open for DOF reasons (say f4), SS 1/300 (to stop motion) - ISO wherever it need to be to allow the above settings. Please note the figures quoted are only to illustrate the concept.

You can PP noise out a damn sight easier (or less noticably) than you can with either motion blur or softness (due to focus or shooting wide open). Blur is very difficult to remove but noise reductions programmes (noise ninja, noiseware etc) are easy and quick with pretty good results.

tonylong
26th of November 2009 (Thu), 13:50
I don't often shoot wide open, simply because I like having a bit more depth of field than wide open gives me. Also, regarding the "sweet spot", different lenses will have different characteristics, and it's useful to get to know your gear in that regards -- if you have a lens that is noticeably soft wide open, well, that would be good to know. Also if you have a lens that stands out for wide open sharpness, that would also be good to know.

There are exceptions to my tendency to shoot somewhat stopped down, and I am quite comfortable with those exceptions, just like there are times when I'll stop down a bit beyond the "diffraction" f-stop for specific reasons. Get familiar and comfortable with the conditions and "best practices/techniques" of the shooting you do, and things will fall into place.

There will of course be "learning moments" when you get home and review a shot "or maybe a bunch of shots" and your response will be "FAIL!!!", but these can be valuable lessons, not just a time when you want to ditch all your gear and take up another hobbe:)!

ckckevin
26th of November 2009 (Thu), 18:02
There will of course be "learning moments" when you get home and review a shot "or maybe a bunch of shots" and your response will be "FAIL!!!", but these can be valuable lessons, not just a time when you want to ditch all your gear and take up another hobbe:)!

and or a moment of glory when you found out that one of the shots looks much better in a big screen.:D

RDKirk
26th of November 2009 (Thu), 23:36
You can PP noise out a damn sight easier (or less noticably) than you can with either motion blur or softness (due to focus or shooting wide open). Blur is very difficult to remove but noise reductions programmes (noise ninja, noiseware etc) are easy and quick with pretty good results.

Back in the film days, we pretty much had to live with the grain, but the decision path was about the same. The last factor to consider was ISO, after determining the shutter speed and aperture necessary for the picture we had in mind. Digital just makes that final factor even less of a worry.

Some people will say, "But you had to choose the film (thus the ISO) first--before even setting out on the shooting session." Well, not really. I, at least, determined before loading the film what range of shutter speeds and apertures I'd need. I loaded film for the shutter speeds and apertures I expected to use in the situation I was heading in to. If I were going to shoot indoor sports, it was the known need for high shutter speeds that dictated the film choice.

neilwood32
27th of November 2009 (Fri), 07:19
Back in the film days, we pretty much had to live with the grain, but the decision path was about the same. The last factor to consider was ISO, after determining the shutter speed and aperture necessary for the picture we had in mind. Digital just makes that final factor even less of a worry.

Some people will say, "But you had to choose the film (thus the ISO) first--before even setting out on the shooting session." Well, not really. I, at least, determined before loading the film what range of shutter speeds and apertures I'd need. I loaded film for the shutter speeds and apertures I expected to use in the situation I was heading in to. If I were going to shoot indoor sports, it was the known need for high shutter speeds that dictated the film choice.

I never shot much film - apart from a Kodak automatic 35mm and a 110, but even as an inexperienced guy, you knew that you needed a fast film for action but could use a slower film for scenery. but you would certainly try to avoid shootiing landscapes with ISO 800+ film. I didnt know about shutter speeds/apertures at the time though.

Now i wouldnt hesitate to use any ISO (apart from H2 on the 50D)if i felt i needed it because its so easy to reduce the noise.