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06-17-2013, 03:07 AM   #1
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The kit lens does f/40

f/40 is quite rare for 35mm DSLR lenses. Why would you ever want f/40?

Because you can get 1/10 shutter speeds without filters in full daylight sun!

And you can see all your sensor dust clearly at the same time. Wow do I have a lot of sensor dust.


Regards,
--Anders.

06-17-2013, 04:02 AM   #2
Ash
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Even f/40 can have insufficient DoF at 55mm when shooting some landscape scenes. At that aperture, the kit lens does suffer from a lot of diffraction and poor contrast.
06-17-2013, 05:39 AM   #3
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Are those birds or dust?
06-17-2013, 06:17 AM   #4
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QuoteOriginally posted by Ash Quote
Even f/40 can have insufficient DoF at 55mm when shooting some landscape scenes. At that aperture, the kit lens does suffer from a lot of diffraction and poor contrast.
So about the same result as using a China made ND filter.

06-17-2013, 06:21 AM   #5
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QuoteOriginally posted by Eulogy Quote
So about the same result as using a China made ND filter.
You can call it lomo maybe?
06-17-2013, 06:22 AM   #6
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Ha, yeah. But the result isnt as bad as I thought it would be. Just clone out the dust, lower the clarity, incrfease sharpness and youre good
06-17-2013, 07:29 AM   #7
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QuoteOriginally posted by Aristophanes Quote
Are those birds or dust?
I had to read the original post a second time to see it, but yes, the OP says it is dust.

QuoteOriginally posted by asp1880 Quote
And you can see all your sensor dust clearly at the same time. Wow do I have a lot of sensor dust.
06-17-2013, 09:22 AM   #8
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QuoteOriginally posted by Ash Quote
Even f/40 can have insufficient DoF at 55mm when shooting some landscape scenes. At that aperture, the kit lens does suffer from a lot of diffraction and poor contrast.
Rubbish.




06-17-2013, 10:01 AM   #9
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The "fence test" with the original SMC Pentax-DA 18~55mm AL on the K-01. It is quicker than trying to put into words the fidelity across the plane at each setting
In this link are 6 camera jpgs, full screen button is bottom right.
18_f3.5, 18_f8, 18_f22
55_f5.6, 55_f8, 55_f40

https://www.box.com/s/d3whwi53hgyff7k4ocng
06-17-2013, 11:53 AM   #10
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Ive used it when trying to get the sun in the frame and light the subject ith the on board flash (fill flash). f/40 allowed for 1/180sec shutter speed which is maximum sync speed for pentax.
06-17-2013, 01:19 PM   #11
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QuoteOriginally posted by Ash Quote
Even f/40 can have insufficient DoF at 55mm when shooting some landscape scenes. At that aperture, the kit lens does suffer from a lot of diffraction and poor contrast.
With those settings you can get everything in focus between 2 meter and the horizon.
I've no idea what kind of landscape you've in mind?
06-17-2013, 01:57 PM   #12
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QuoteOriginally posted by Anvh Quote
I've no idea what kind of landscape you've in mind?
Something like this?



My mom took that picture with her $80 P&S, hence the huge DOF.

Just saying, there's a place for everything, no matter how ridiculous it sounds.
06-17-2013, 02:16 PM   #13
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That's right. Some P&S cameras have f/64 and above, making landscapes with DoF from <1m to infinity a possibility. It would be useful in the setting of landscapes with for example lush green grass foreground with a background of mountains in the distance. I don't think I've personally desired that DoF much in scenes, but I do have a wide angle zoom that at 12mm and f/22 can give me very deep DoF when I need it.

In any case, I've seen and compared what the f/40 kit lens can do compared to say the Tamron 28-75 at 50mm and f/22, and even there I can see the difference in contrast and sharpness, let alone the results at f/8.
06-17-2013, 03:01 PM   #14
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thanks for the example XD
06-17-2013, 03:34 PM   #15
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If you really need that crazy huge DOF, you're probably better off shooting with a wider angle lens and cropping than shooting at f/40. Chances are you'll be losing less real resolution by cropping than you will from diffraction at that small an aperture.
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