[zkarj]

And if anyone else is interested in getting hold of a used WR, PM me.

[richandfleur]

Hi Richard,

I think you're the first one to draw attention to the quick focusing of the lens.

I worked out for my use case scenario, I probably won't use the lens often enough to justify the expense to get faster focusing so I'm happy to have acquired an older screw drive version.

You also mentioned you have the 16-85 though, and one of the reasons I didn't want to spend too much at the longer end is I found I actually take quite a lot of photos at the wide end so if I'm going to spend up on anything, this would be a better area to invest.
What are your thoughts on this lens? It's not PLM, although has a motor rather than screwdrive, but I notice a few reviewers mention some quirky focusing behaviour at the wider end with a tendency to miss focus a bit too often.

Morning,

I'd have to sit down and have a play with this. From memory I did find some oddness when calibrating this lens. It's that annoying scenario of where do you calibrate a zoom lens for, when the focussing issues can be different/non linear across the zoom range.
Between the two of these lenses though, that's pretty much me setup for most things. I would put on one of the primes for anything needing that extra depth of field separation (which of course is then highly dependant on teh point of focus being correct).

I guess my issue with the DSLR approach is that the focus is usually bang on where it's trying to aim, but there are no smarts avialable to work out if that point makes sense. Even in autofocus, it's manual in terms of you point and hope the camera sees what you are pointing at. (Iuse centre point only, single focus mode most of the time).
Personally I've had way way too many group shots/portraits over the years, where a line of people are blurry whilst the hedge miles off in the background is in perfect focus.
A cellphone or mirrorless would detect the faces/eyes even and focus there, and you'd manually have to overide that if you actually did want to focus on the rear hedge.

---------- Post added 10-01-21 at 09:50 AM ----------

For the first time, I am tempted to leave the camera in AF.C.

Me too

I found the K-3 had the focus behaviour configuration settings I needed, that were missing from the K-30 previuosly.
It kind of worked with the older screwdrive zoom.
I'm looking forward to trying this again with the new PLM.

Biggest issue previously was that whilst subject coming towards you was locked in focus, it had moved forwards again by the time the shot was actually taken.
Some settings helped with this more than others, but it was extremely common to have the kids out of focus and the back of their bike/or people running futher back behind them now in the original focus confirmation spot.
Hopeing the PLM tracks better.

The newer camera models may do this much better than my original mk i K-3 of course too.

[Kiwi645hauler]

I found the K-3 had the focus behaviour configuration settings I needed, that were missing from the K-30 previuosly.
It kind of worked with the older screwdrive zoom.
I'm looking forward to trying this again with the new PLM.

Biggest issue previously was that whilst subject coming towards you was locked in focus, it had moved forwards again by the time the shot was actually taken.
Some settings helped with this more than others, but it was extremely common to have the kids out of focus and the back of their bike/or people running futher back behind them now in the original focus confirmation spot.
Hopeing the PLM tracks better.

The newer camera models may do this much better than my original mk i K-3 of course too.

The PLM Tech is pretty impressive with how accurate and how fast it is on the 55-300, lets hope Pentax stick with it and carry on developing it in other lenses.
One of the big things to improve tracking, Pentax will need to get onto the AF systems inside the bodies as well, a big part of tracking AF is the algorithms in the AF Firmware for prediction and detection of movement in both subject and camera to guess and follow the subject for the AF to keep up. PLM Motors will definitely help on that side as they are much faster than the SDM motors

[Kiwizinho]

Personally I've had way way too many group shots/portraits over the years, where a line of people are blurry whilst the hedge miles off in the background is in perfect focus.
A cellphone or mirrorless would detect the faces/eyes even and focus there, and you'd manually have to overide that if you actually did want to focus on the rear hedge.

That's probably less of an issue for me as group portraits aren't a big part of my photography, and I think even the smarts of a phone or mirrorless would struggle with figuring out which fungus out of a colony of them, or which specific flower I want to focus on. I'm not sure of the viability of insect detect AF, although I guess insect eye detect would do, but the structure of insect eyes is very different to vertebrate eyes, so while theoretically possible, I'm not sure whether any camera maker would implement a bug tracking algorithm, although it could be useful.

It's interesting looking at how Google Photos AI has classified the photos I've uploaded there. Whether a scene detect processor in a camera could do better than that I don't know.
It seems to do pretty well, but the subject it seems to have most trouble with is mountains. It recognises mountains OK, but also quite a lot of other things that are not mountains. Given that landscapes are one of the things I photograph the most, any camera scene detection would have to do better than Google photos, but mountains generally aren't moving (and when they are, photographing them is probably the last thing you're worried about) so object tracking isn't necessary.

[richandfleur]

Yeah anything static like a outdor scenery shot, or anywhere a tripod is used, I tend to use manual focus and often live view with punch in zoom via the rear screen.
Af for me is lacking where people are involved and where tracking is involved - in the hardest sense where the subject is coming towards me etc. Sadly that's where I want the optical viewfinder too, so a bit stuck really.

[zkarj]

So... yeah... birds in flight with the PLM? Tick!

I didn't always believe the lens but the results speak for themselves. It's fair to say most of the in-flight shots were tack sharp. A handful were not quite on the money, and a couple were a decent miss, though the latter category was against a challenging background. I had so many crisp shots of the Caspian Tern I was able to be really picky with the angles I chose for publication. All of these are pretty heavy crops, too, as I couldn't get super close to any of them.

10 published shots here. (Most of the rest are not in flight, but still very pleasing to me.)

[Class A]

Where does the light meter reside - it would be up top wouldn't it?

Yes, it is attached to the pentaprism.

BTW, modern metering chips have sufficiently high resolution so that they can support subject detection, e.g., faces or even eyes. The K-3 III makes use of this ability to soften the "D" in "DSLR" by allowing eye-AF, even when using the optical viewfinder and/or tracking of moving subjects for informing AF-C acquisition. In both cases, the actual (PDAF) focusing is still done via the separate AF module, but the metering chips allows the camera to select the appropriate AF point.

Otherwise the main body of noise we experience is simply a function of a light starved pixel and the errors that come from amplifying that weak signal.

In low light the signal (light) itself is noisy. Even if the amplification of the weak signal were perfect (which it is very close to with modern sensors), you'd still see a "salt & pepper" rendering of the scene.
Most of the noise you see in a high-ISO (<- read "low light") image is just proof of the stochastic nature of light which is normally masked by enormous amounts of photons but can be observed when you get into low photon count territory.

With very long exposures you obviously get a good noise contribution from the sensor due to thermal noise (as the sensor is heating up during exposure and its nearly perfect photon to electron conversion deteriorates).

A smaller format gives greater dof (depth of field) for a given fstop.

In some sense yes, but not really.
The f-stop numbers only appear to be equal as they are numerically the same, but their meaning varies along with the format.
MF-f/2 is very different to Pentax Q-f/2. It is rather misleading that the same numbers are used in both cases.
Just like MF-50mm is very different to Pentax Q-50mm.

Note that if you move a lens from an FF camera to an APS-C camera and keep the subject distance the same and the f-stop the same, it is the APS-C camera that will produce a shallower DOF image (due to the higher enlargement factor of APS-C compared to FF). A DOF calculator will confirm this. Of course this is an apples to oranges comparison as the images will look very different (due to the different FOV), but it is worth pondering about the actual effects of using a smaller format.

That is why on Full frame if doing a closeup I often pull back with cropping to apsc in mind to get a bit more dof.

You gain the DOF by increasing the distance to the subject (not by changing the format).

You actually lose DOF by cropping to APS-C (as cropping is equivalent to using a longer lens (disregarding pixel count loss)). Again, using the same lens on APS-C and FF leads to a shallower DOF (if you keep the camera distance the same).

In your scenario, you gain more DOF by increasing the distance to the subject than you lose DOF by (effectively) increasing the focal length, hence your technique works.

[GUB]

Yes, it is attached to the pentaprism.

BTW, modern metering chips have sufficiently high resolution so that they can support subject detection, e.g., faces or even eyes. The K-3 III makes use of this ability to soften the "D" in "DSLR" by allowing eye-AF, even when using the optical viewfinder and/or tracking of moving subjects for informing AF-C acquisition. In both cases, the actual (PDAF) focusing is still done via the separate AF module, but the metering chips allows the camera to select the appropriate AF point.


In low light the signal (light) itself is noisy. Even if the amplification of the weak signal were perfect (which it is very close to with modern sensors), you'd still see a "salt & pepper" rendering of the scene.
Most of the noise you see in a high-ISO (<- read "low light") image is just proof of the stochastic nature of light which is normally masked by enormous amounts of photons but can be observed when you get into low photon count territory.

With very long exposures you obviously get a good noise contribution from the sensor due to thermal noise (as the sensor is heating up during exposure and its nearly perfect photon to electron conversion deteriorates).


In some sense yes, but not really.
The f-stop numbers only appear to be equal as they are numerically the same, but their meaning varies along with the format.
MF-f/2 is very different to Pentax Q-f/2. It is rather misleading that the same numbers are used in both cases.
Just like MF-50mm is very different to Pentax Q-50mm.

Note that if you move a lens from an FF camera to an APS-C camera and keep the subject distance the same and the f-stop the same, it is the APS-C camera that will produce a shallower DOF image (due to the higher enlargement factor of APS-C compared to FF). A DOF calculator will confirm this. Of course this is an apples to oranges comparison as the images will look very different (due to the different FOV), but it is worth pondering about the actual effects of using a smaller format.


You gain the DOF by increasing the distance to the subject (not by changing the format).

You actually lose DOF by cropping to APS-C (as cropping is equivalent to using a longer lens (disregarding pixel count loss)). Again, using the same lens on APS-C and FF leads to a shallower DOF (if you keep the camera distance the same).

In your scenario, you gain more DOF by increasing the distance to the subject than you lose DOF by (effectively) increasing the focal length, hence your technique works.

First of all I am not disagreeing with anything.
I look at these things in a "in the field " perspective. So if I have a flower to photograph and my macro is an A50 2.8 then it is natural to fill the frame with either format. So with the FF I will be say 1000mm from the subject then with apsc I will be 1500mm. So the apsc ends up with greater dof. And if you think about it that is how most people operate - they place the camera at the place that composes the image appropriately ( not to a given magnification). To take the magnification approach just unnecessarily complicates it for entry level photography.

Of course this is an apples to oranges comparison as the images will look very different (due to the different FOV), but it is worth pondering about the actual effects of using a smaller format.

This is the same point - most people don't want an "apple to orange" they want a cause and effect of a given lens /fstop on the same composition. So if I put my 50mm 2.8 on my Q then to fill frame that flower I am now 5000mm away from it with significantly greater dof in the final image.

[Clarkey]

I finally wrote this up. The core of the article is how to deal with VueScan's multi-crop settings (which defeated me for years) but I have written it up as a complete workflow.

Scanning Negatives with VueScan (Multi-frame)

And in other news, I see a package is out for delivery and I have three days off later this week. Expect, at the very least, excitement. And probably photos.

Well done. I have been scanning the last couple of days, and may have a couple of additional feedback points regarding colour correction. The buffer setting on blue skies certainly makes a difference if you are using auto levels.

[zkarj]

Well done. I have been scanning the last couple of days, and may have a couple of additional feedback points regarding colour correction. The buffer setting on blue skies certainly makes a difference if you are using auto levels.

Thanks. I have already identified a few other points need updating that I discovered after I published. (Of course.) The chief one I recall now is the rotation arrows in the preview window directly affect the settings in the sidebar and the relationship here is a little curious regarding which frames it affects. More testing needed.

[GUB]

New topic - hopefully one of you lot know about this!.
Our Tramping Club is looking to get a audio visual tv wall mounted in the room.
Do any new TVs have wireless connectivity? Or any other way for that matter.
I am pretty sure I can rig up chromecast to a wireless modem that is unconnected to the internet. That means any visitor can just log in and cast.
And there is simple dongles available that do the same.
Given that we have the opportunity to choose the right TV is there something to look out for.?
I am just not up to speed on this stuff. And I have to say I hate the way my camera club uses a HDMI cable and are jammed up under the TV.

[NZ_Ross]

I am pretty sure I can rig up chromecast to a wireless modem that is unconnected to the internet. That means any visitor can just log in and cast.

We use that at work, and it works well. Smart TV's will also link to wifi etc, but are relatively expensive.

If you are planning to chomecast you can do what we did and buy a monster flat panel sold for commercial premises without all the TV and internet stuff. Much cheaper than normal smart TV's and you can access everything you want streaming over the chrome cast in any case.

[GUB]

We use that at work, and it works well. Smart TV's will also link to wifi etc, but are relatively expensive.

If you are planning to chomecast you can do what we did and buy a monster flat panel sold for commercial premises without all the TV and internet stuff. Much cheaper than normal smart TV's and you can access everything you want streaming over the chrome cast in any case.

Nice one Ross - that validates what I was thinking. Just to check - the wifi modem doesn't have to be connected to the internet does it? (I know that is the usual purpose).

[GUB]

Another thing - I have used my old standard resolution chromecast on our new 4K here at home and it works fine and fills the screen. Of course the screen is at standard resolution - do you think that is a loss in a 60 person meeting - no one is going to be near the screen.?

[NZ_Ross]

Nice one Ross - that validates what I was thinking. Just to check - the wifi modem doesn't have to be connected to the internet does it? (I know that is the usual purpose).

Our one is connected to the internet. I would have to check with my staff member who set it all up, and he is on leave this week. We have our panel set to 1080p and it is fine for everything we are doing, but that is more presentations and video conferencing, rather than specifically viewing photos