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09-10-2021, 09:54 PM - 2 Likes   #18031
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But forsaking the 55-300 for today, I had the Tamron 90 f/2.8 on the camera and it seemed appropriate for these celebrations of Spring.





09-10-2021, 10:38 PM - 2 Likes   #18032
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Well it took me longer to arrange these at such a size to fit within forum guidelines than it did to take all the photos and import them.

This is the 55-300 ED WR lens at 300mm, focused about 2.5m away, giving a minimum DOF of around 14mm. The tomato plant stalk, including all hairs back and front, is <5mm deep. The focus was set with AF on the front of the stalk and then switched to MF to maintain it. Focus peaking showed a mostly white stalk. Of course it was on a tripod and had the 2s timer set. The camera was in Av mode and I let it pick the shutter and ISO, as this is how I use the camera normally. ISO levels resulting were 2500 @ f/5.8, 3200 @ f/6.3 & f/7.1, 4000 @ f/8, 5000 @ f/9, and 6400 @ f/10 and above.

The "processing" involved DxO PhotoLab 4, where I let it use all its camera and lens-specific data to "correct" the image at default values. These were lens vignetting, colour rendering, lens sharpness, chromatic aberrations, and distortion. Beyond this, I applied a super tight crop and a half stop reduction in exposure as I had blown a few highlights. No noise reduction was applied. All settings were made to the first image and then automatically applied to all the others.

The output was to 100-quality JPEGs at original size, using "Bicubic sharpest" setting and no scaling. These were then combined in Affinity Photo, labels added, and the final output JPEGs at 95-quality to fit within forum file size limits.

I reckon anything between f/8 and f/16 is pretty decent. Lower than f/8 has definite halos and above f/16 starts to lose serious definition.
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09-10-2021, 11:01 PM   #18033
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QuoteOriginally posted by zkarj Quote
I've just done a study of my 55-300 shooting parameters using Lightroom Classic's nifty filtering tools. I said before I almost always shoot at f/11. Certainly since I've had the WR, there was a period where I seem to have tried out f/8 for a bit before returning to f/11 and all the other stops barely get a look in. But with the previous ED model, I guess I took a while to learn where that sweet spot was, but once again, f/11 rules the roost. I also thought it would be interesting to look at the focal length used. I would have picked that 300mm would rule here, but I was surprised by how uniform the other values were (noting that LR normalises these to a discrete set of numbers).

The ED was used 11 Jan 2009 2 Oct 2017 (8.8 years)
The WR has been in use 4 Oct 2017 present (4 years)
Interesting stats. Unfortunately, although it looks like you use 300mm more than any other focal length, it's still only around 1/3 of the total images taken with the lens, so not sure if you can justify a 300mm prime, but if you can cover most of those other focal lengths with another zoom, then a prime might make sense if you can find one at a decent price.

---------- Post added 09-11-21 at 06:09 PM ----------

QuoteOriginally posted by zkarj Quote
But forsaking the 55-300 for today, I had the Tamron 90 f/2.8 on the camera and it seemed appropriate for these celebrations of Spring.
Very nice. I like the Tamron 90/2.8. I considered selling it when I got the D-FA 100/2.8, as the Pentax lens has quickshift and weather sealing that the Tamron doesn't, but for portraits, the 10mm difference in focal length is significant, and I feel the Tamron makes nicer portraits. In a portrait situation, I'm less likely to need weather sealing, and AF works fine.

I need to do another lens comparison though, as when I decided to keep the Tamron, I didn't have the DA* 50-135/2.8 which I have now, and that covers the same focal length, but it is a zoom, and primes are typically sharper. I guess I should do a comparison, and if the DA* lens is good enough, I may not need the Tamron any longer.

---------- Post added 09-11-21 at 06:17 PM ----------

QuoteOriginally posted by zkarj Quote

I reckon anything between f/8 and f/16 is pretty decent. Lower than f/8 has definite halos and above f/16 starts to lose serious definition.
Between f/9 - f/11 it's hard to see much difference, and I think f/8 is only slightly behind. It's certainly not a fast lens, but if f/9 works as well as f/11, that does make it a bit more useful.
09-10-2021, 11:28 PM - 1 Like   #18034
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QuoteOriginally posted by Kiwizinho Quote
Unfortunately, although it looks like you use 300mm more than any other focal length, it's still only around 1/3 of the total images taken with the lens, so not sure if you can justify a 300mm prime, but if you can cover most of those other focal lengths with another zoom, then a prime might make sense if you can find one at a decent price.
I hadn't considered it as a proportion. It would be interesting (if a PITA to compile) to see how the focal lengths vary over time as this, I think, would show that the 55-300 is the right lens for me. For birding, a 300mm prime is probably superior most of the time as I am rarely too close, but when it comes to aircraft I'm using a big chunk of that zoom range from shot to shot.

Case in point... these two shots were taken 7 seconds apart, at 55 and 260mm respectively.




09-10-2021, 11:47 PM   #18035
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Same shots as above but with default DeepPRIME noise reduction applied.
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09-11-2021, 12:46 AM   #18036
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QuoteOriginally posted by zkarj Quote
Same shots as above but with default DeepPRIME noise reduction applied.
A remarkably consistent set of results.
It is interesting also to look at the drop off in crispness of the green stem as the denoising increases.
I would have to say even f5.8 is usable and roughly equivalent to the loss of sharpness that the denoise did to whatever iso f18 was.
Nice work.
09-11-2021, 01:47 AM   #18037
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QuoteOriginally posted by GUB Quote
It is interesting also to look at the drop off in crispness of the green stem as the denoising increases.
There are some people in the DxO forums who reckon the default setting of 40 is too overbearing, but as I had gone with defaults on everything else I went with it. I tend to use 25 as my starting point and only ramp it up when needed.

I was thinking a more useful set of results would be with a consistent ISO, but then a longer shutter also increases noise. As mentioned, I largely used the camera as I always do, and I always let the ISO ride up to 6400 when required. Which is quite astonishing if I go back to my K10D days. That's what actually got me to upgrade from K10D to K-5.

I should also include this for context. It really is a small crop of the frame.

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Last edited by zkarj; 09-11-2021 at 01:50 AM. Reason: Added pic
09-11-2021, 03:53 AM - 1 Like   #18038
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QuoteOriginally posted by zkarj Quote
but then a longer shutter also increases noise.
No not right but there is plenty of reason in aviation photog to keep shutter speed up.
Your results are excellent - enough so that if I would suggest f8 could be your new f11. Not sure how that applies for autofocus in your aviation environment tho. Even if you halve the accepted circle of confusion for apsc cameras there is not a heck of a lot of difference in dof out at the hyperfocal distance. Comparison in screenshots.
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09-11-2021, 01:58 PM - 1 Like   #18039
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QuoteOriginally posted by GUB Quote
No not right but there is plenty of reason in aviation photog to keep shutter speed up.
Oh, OK. Maybe only for very long shutter times? I was sure I'd heard it somewhere.

But yes, keeping shutter speed tight with fast moving objects helps a lot, even if it does tend to stop propellers and rotors. I find on average my shots show movement but also make it very obvious the number and even shape of the blades. There are some av-photogs who insist an entire prop-arc be visible, but I looked up a typical aircraft the Dash 8 and its takeoff RPM is 1200, so it would mean 1/20" shutter which I find rather long and the aircraft will move about 2.5m forward in that time, at takeoff speed.
09-11-2021, 03:09 PM - 1 Like   #18040
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QuoteOriginally posted by zkarj Quote
Oh, OK. Maybe only for very long shutter times? I was sure I'd heard it somewhere.
Yes for exposures in minutes.
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.
09-11-2021, 03:12 PM   #18041
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QuoteOriginally posted by zkarj Quote
Oh, OK. Maybe only for very long shutter times? I was sure I'd heard it somewhere.

But yes, keeping shutter speed tight with fast moving objects helps a lot, even if it does tend to stop propellers and rotors. I find on average my shots show movement but also make it very obvious the number and even shape of the blades. There are some av-photogs who insist an entire prop-arc be visible, but I looked up a typical aircraft the Dash 8 and its takeoff RPM is 1200, so it would mean 1/20" shutter which I find rather long and the aircraft will move about 2.5m forward in that time, at takeoff speed.
An entire prop arc is a bit extreme. Trying to pan smoothly that much is pretty hard to achieve. As long as there's some prop or motor movement, I'd be happy. It does tend to look a bit unnatural otherwise.
09-11-2021, 04:03 PM   #18042
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QuoteOriginally posted by Kiwizinho Quote
An entire prop arc is a bit extreme. Trying to pan smoothly that much is pretty hard to achieve.
It's not just your ability to pan.If you're close, the angle of the shot changes as well. I have photos that have the aircraft extremities blurred where the middle is not and this is the only explanation I can think of.
09-11-2021, 08:24 PM - 2 Likes   #18043
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Any of you film guys want this lot?
2003 so still current
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09-12-2021, 01:42 AM   #18044
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I was interested to see if it was true that you had a bit more leeway with diffraction with full frame. I guess when you are pixel peeping there is no difference. Looks like f11 is better than f16
I didn't have a hairy tomato so I lived a bit more dangerously and brought a sample of Onga onga home. (Urtica ferox). It has killed many a dog and a couple of pighunters.
The very longest of the white spines are about 10mm long. I focused on the pair in the middle. You may just spot in the sharpest samples a tiny drop of toxin on the needle tip of the right hand one.That drop is 3 pixels across -- .015 of a mm diameter.
This is from 2.5 meters. The six grid had default sharpen and no denoise.
In the 4 grid test I compared Darktable default denoise and sharpen application
The 1960s Tak does a good job but it was interesting the images got progressively lighter as I stopped down and doubled the shutter speed. Perhaps half a stop error by f22.
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09-12-2021, 02:26 PM   #18045
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QuoteOriginally posted by GUB Quote
No not right but there is plenty of reason in aviation photog to keep shutter speed up.
Your results are excellent - enough so that if I would suggest f8 could be your new f11. Not sure how that applies for autofocus in your aviation environment tho. Even if you halve the accepted circle of confusion for apsc cameras there is not a heck of a lot of difference in dof out at the hyperfocal distance. Comparison in screenshots.
The big thing for Aviation photography where propellers/rotors are involved, i tend to keep the ISO as low as possible, and run between 1/125 & 1/320 of a second, which tends with my 300mm lens to operate at f11-15 depending on day.
The only time i go any higher is for those airplanes that dont have a fan out front

---------- Post added 09-12-21 at 02:44 PM ----------

QuoteOriginally posted by Transit Quote
Any of you film guys want this lot?
2003 so still current
Dang.. I have half a fridge full of film, mostly 120 but some 35mm, i put a new battery in my MZ-50 over the weekend to go photograph some stuff but the shutter is dead I am trying to decide do i keep the MZ and Pentax 35mm or just rely on my *COUGH* Minolta Dynax 7 *COUGH* for my 35mm shooting
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