[MarinatedHerring]

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Last edited by MarinatedHerring; 02-09-2013 at 02:32 PM. Reason: leaving

[crewl1]

In the second it looks like you missed focus. Actually the pelican to the right of the gull is sharp.
Focus is critical on adapted lenses because any aberrations or fringing will be accentuated by the Q.
Also, if the lens tends to have Purple Fringing you wil probably see it on high contrast areas such as the seagull in the middle.
It is not that bad, and could be managed by post process.
Try stopping the lens down a bit for more depth of field and to eliminate the fringing.
Shutter speed looks OK because the flying pelican's wings are not blurred.

[MarinatedHerring]

In the second it looks like you missed focus. Actually the pelican to the right of the gull is sharp.
Try stopping the lens down a bit for more depth of field and to eliminate the fringing.
Focus is critical on adapted lenses because any aberrations or fringing will be accentuated by the Q.
Also, if the lens tends to have Purple Fringing you wil probably see it on high contrast areas such as the seagull in the middle.
It is not that bad, and could be managed by post process.
Try stopping the lens down a bit for more depth of field and to eliminate the fringing.
Shutter speed looks OK because the flying pelican's wings are not blurred.

Thank you for the advice crewl1! By stopping the lens down do you mean to bring the aperture down from like 8 to to 5,6 or 4?

Focusing was very difficult (the sun was right behind me) and I am considering getting an LCD viewfinder hood like someone else posted on a thread in this section.

Side note: I don't have a hood for this particular lens so I was using 2 starbucks coffee cardboard heat protectors. Worked well!

[crewl1]

You'll have to see what the lens sweet spot is but I would try f5.6 as it seems to be the most common point that many lenses do best on the Q.
Faster apertures may be soft or give CA issues, while slower f8 and beyond causes loss of detail on the Q sensor due to diffraction.

To help with focus, set the MF assist in the menu to 4x and hit OK to activate it so you will get a magnified view on the LCD.
Some folks like to turn on focus peaking as well.

Way to improvise the hood

[crewl1]

I'm using a cheap LCD loupe for a Nikon 1 system that with a little drilling to give the tripod mount a little sideways adjustment is working out well.

V5 3" 4 3 LCD Viewfinder 2 8x Magnifier Extender Hood Eyecup for Nikon 1 J1 DSLR | eBay

[ChrisJ]

The problem more likely is the electronic shutter which takes 1/7th of a second to record the image, and is effectively your shutter speed, no matter what shutter speed you have set. If the camera or subject move during the 1/7th of a second it is recorded by the sensor and you get a blurred shot which LOOKS like it's out of focus.

The cure for this is (expensively) to use the Pentax Q to K adapter that has a mechanical shutter built in and totally gets around the problem. C'mon Pentax make this essential bit of gear cheaper, it currently costs more than the camera!

Chris

[drougge]

Thank you for the advice crewl1! By stopping the lens down do you mean to bring the aperture down from like 8 to to 5,6 or 4?

Down means a higher number. (It's from "close down", making the aperture smaller.) In theory f/4 is best on the Q, in practice it's often a smaller aperture (higher number).

Focusing was very difficult (the sun was right behind me) and I am considering getting an LCD viewfinder hood like someone else posted on a thread in this section.

Get a viewfinder hood, they're cheap.

Almost no older lenses will be colour corrected in out of focus areas (and most newer ones won't be either), so if you see differences in CA it's almost always a difference in focus.

[Na Horuk]

Also, are you using a lens hood or filters? Remove filters (if any) and add a hood, might improve overall IQ

[snostorm]

The problem more likely is the electronic shutter which takes 1/7th of a second to record the image, and is effectively your shutter speed, no matter what shutter speed you have set. If the camera or subject move during the 1/7th of a second it is recorded by the sensor and you get a blurred shot which LOOKS like it's out of focus.

The cure for this is (expensively) to use the Pentax Q to K adapter that has a mechanical shutter built in and totally gets around the problem. C'mon Pentax make this essential bit of gear cheaper, it currently costs more than the camera!

Hi Chris,

From my own experience, reinforced by numerous examples posted here, I have to say that this is just not true. There is no way that results shown with the shots using the electronic shutter and 3rd party adapted telephoto lenses could have been done with a virtual 1/7 sec exposure.or anything anywhere close. I think you're confusing the time it takes to dump the entire sensor's information after it takes an exposure with the time it takes to make the exposure.



This one was 1/400 with the Q, RJ adapter, and DA 55-300 @ 300mm handheld. There is no way to get this shot with this level of detail with a shutter speed of 1/7 sec handheld with any camera and lens combination unless the subject is a taxidermy specimen and you're shooting very close with a short lens -- and a great deal of luck and solid technique would still be needed I would think.

This one was taken at 1/200 at the same settings, and the finer detail is smoothed, as would be expected from the doubled exposure time.



If there was no difference in effective shutter speed, one would expect essentially the same kind of results in either. During this set, most of the shots were taken when the birds were in shadow, and none of the shots at the slower shutter speeds even approached the same level of detail captured as the few lit by direct sunlight where I could take advantage of higher shutter speeds.

Of course, this is not definitive proof, but the results are very consistent (two stops under the 1/FL EQ in shutter speed with SR as a threshold for finely detailed shots handheld) with all of my experience shooting birds over the past 8 or so years with different mechanical shuttered cameras.

Also, your explanation is inconsistent with the 1/13 sec sync speed of the electronic shutter with flash on the Q and the 1/30 sync speed with electronic shutter in the Q10. If it takes 1/7 sec to expose all of the pixels on the sensor, the mere presence of flash could not make this 1/2 or 1/4 of that speed. It might take that long to dump the information from the sensor to the image file in main processing engine in the camera, but not to record the exposure.

Scott

[drougge]

I don't know where he got 1/7, but it's certainly true that the "whole frame time" is a lot longer than the shutter time for short shutter times with lenses without a shutter. This doesn't stop them from being sharp (the time is still true, locally), just from having the whole frame exposed at the same time. Which is much less likely to be a problem, though it certainly happens.

[VisualDarkness]

Yep, the time to read the sensor makes things pretty funny at times. I shot a bird feeder handheld and it got skewed to the left or right or even a mix of them. It would be interesting to find the exact time it takes to read the sensor and would guess something equal to 1/100-1/300 but I don't know at all. It would be pretty easy to find out if a person can build some precise mechanical moving test subject with varying speed that you can shoot from the side.

[ChrisJ]

Hi Chris,

From my own experience, reinforced by numerous examples posted here, I have to say that this is just not true. There is no way that results shown with the shots using the electronic shutter and 3rd party adapted telephoto lenses could have been done with a virtual 1/7 sec exposure.or anything anywhere close. I think you're confusing the time it takes to dump the entire sensor's information after it takes an exposure with the time it takes to make the exposure.



This one was 1/400 with the Q, RJ adapter, and DA 55-300 @ 300mm handheld. There is no way to get this shot with this level of detail with a shutter speed of 1/7 sec handheld with any camera and lens combination unless the subject is a taxidermy specimen and you're shooting very close with a short lens -- and a great deal of luck and solid technique would still be needed I would think.

This one was taken at 1/200 at the same settings, and the finer detail is smoothed, as would be expected from the doubled exposure time.



If there was no difference in effective shutter speed, one would expect essentially the same kind of results in either. During this set, most of the shots were taken when the birds were in shadow, and none of the shots at the slower shutter speeds even approached the same level of detail captured as the few lit by direct sunlight where I could take advantage of higher shutter speeds.

Of course, this is not definitive proof, but the results are very consistent (two stops under the 1/FL EQ in shutter speed with SR as a threshold for finely detailed shots handheld) with all of my experience shooting birds over the past 8 or so years with different mechanical shuttered cameras.

Also, your explanation is inconsistent with the 1/13 sec sync speed of the electronic shutter with flash on the Q and the 1/30 sync speed with electronic shutter in the Q10. If it takes 1/7 sec to expose all of the pixels on the sensor, the mere presence of flash could not make this 1/2 or 1/4 of that speed. It might take that long to dump the information from the sensor to the image file in main processing engine in the camera, but not to record the exposure.

Scott

Hi Scott

I am wrong with the 1/7th of a second (don't know where that figure came from - old age probably LOL), but (unfortunately) it is true, the camera takes 1/13th (NOT 1/7th) of a second to complete an electronic shutter scan.

You can see it if you force the camera into selecting it's X speed (the fastest speed it can use where all the sensor is exposed at the same moment). Force the flash on by going into flash menu (the left hand joggle key) and select 'Flash On' (the third option from the left), take the lens off or fit a cheap adapter and lens and the shutter speed will fix at 1/13th of a second, which is the fastest speed the camera can select with these settings.

Fit any lens or adapter with a built in shutter and you can now select any shutter speed with these same settings.

All digital shutters work this way, the sensor in the Q takes 1/13th of a second to scan all the pixels and send them off to the A/D converter. In modes other than the one above what happens is each pixel will be sensitive to whatever the shutter speed you set, but the sensor will still be active for the 1/13 of a second it needs to scan the 12 million pixels. During this time the sensor will react to a changing scene, subject movement or camera shake are the most common.

When a mechanical shutter is present the view the sensor sees is fixed in the time the shutter is open, it still takes 1/13th of second to scan the sensor, but now the scene can't change so subject movement and camera shake is not recorded as the shutter is now closed.

This is the reason why the Pentax Q to K adapter needs to have a built in shutter. Pity it's so expensive.

It's also the same reason why video cameras have 'jello shutter'.

So you are right Scott, I did get the scan time wrong, but it still takes some practice to hand hold a camera,especially with a telephoto lens, steady at 1/13th of a second. Your shots are amazingly sharp.

Chris