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01-19-2022, 02:01 PM   #16
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QuoteOriginally posted by BigMackCam Quote
I would try adding just a little "clarity" or "local contrast" to the Tamron images in post-processing. A lot of these mirror lenses benefit hugely from a bit of assistance where global and local contrast is concerned. I have a 3M-5CA mirror lens from the Soviet Union which, if you get a good example or you're prepared to spend a little time adjusting a not-so-good one (to ensure the rear mirror isn't distorted - many are), is quite-rightly considered to be one of the better lenses of its type out there. It's actually a very capable lens for its age, but it definitely benefits from a small injection of local contrast in post, after which images really "pop". I'd also suggest that magnified Live View, or - at the very least - use of focus peaking are pretty much essential to get consistently accurate focus with these lenses... Green-dot confirmation in PDAF through the viewfinder will only get you in the ball-park, and that's not enough with such shallow DoF...
Yes, when I do an auto-levels on the Tamron images, like the 4 I just posted from the bird feeder, it does a lot for the images.

01-19-2022, 02:08 PM   #17
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I'm more convinced now, but still not %100 sure. Have you tried yet using magnified live view? And if not is there a reason for that? The other question is whether it's on a tripod with self timer or remote? Shake really does matter a lot, especially at these focal lengths.

BTW I'm not implying you're doing something wrong, I just know that with long lenses, there is a whole ton to be gained by improving and then refining technique. The people who post amazing shots with the same lens as others who are frustrated with results from their first supertelephoto; I tend to have a hard time thinking it's variance between the lens copies, rather than variance between the photographers' skills.


One place where these shots clearly show the advantage going to the mirror, though, is the purple fringing. Check out those branches in the foreground with snow behind them!

I hope you're having fun doing these tests. Keep at it (plus real world shooting of course), and I bet your shots from both lenses will continually improve
01-19-2022, 02:09 PM   #18
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QuoteOriginally posted by UncleVanya Quote
Common misunderstanding of the red dot. All that indicates is where the focus point is that the camera is using. The green Hexagon (solid not flickering) is what tells you if focus is stable and achieved.

---------- Post added 01-19-22 at 04:00 PM ----------

It is possible you had the green hexagon lighted up also. But I find magnified live view is more accurate than the hexagon. F8 is also pushing it for PDAF performance which is what the hexagon uses.
I will have to read up on how to get that hexagon to show up in my live view - just tried live view twice and didn't see it. Must be a menu setting....

Thanks!
01-19-2022, 02:12 PM   #19
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QuoteOriginally posted by Michael Piziak Quote
I will have to read up on how to get that hexagon to show up in my live view - just tried live view twice and didn't see it. Must be a menu setting....

Thanks!
AFAIK, the green hexagon is through the viewfinder only, not in Live View.

01-19-2022, 02:13 PM - 1 Like   #20
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QuoteOriginally posted by wadge22 Quote
I'm more convinced now, but still not %100 sure. Have you tried yet using magnified live view? And if not is there a reason for that? The other question is whether it's on a tripod with self timer or remote? Shake really does matter a lot, especially at these focal lengths.

BTW I'm not implying you're doing something wrong, I just know that with long lenses, there is a whole ton to be gained by improving and then refining technique. The people who post amazing shots with the same lens as others who are frustrated with results from their first supertelephoto; I tend to have a hard time thinking it's variance between the lens copies, rather than variance between the photographers' skills.


One place where these shots clearly show the advantage going to the mirror, though, is the purple fringing. Check out those branches in the foreground with snow behind them!

I hope you're having fun doing these tests. Keep at it (plus real world shooting of course), and I bet your shots from both lenses will continually improve

I'm actually placing the camera on a table, on the back deck, pointing it down the yard and taking the shots. Tomorrow I will use a 2 second timer or the remote to take some more images. Also, I need to learn more about how to turn that green hexagon....

Cheers!

---------- Post added 01-19-22 at 02:17 PM ----------

QuoteOriginally posted by luftfluss Quote
AFAIK, the green hexagon is through the viewfinder only, not in Live View.
Oh, ok. I'm learning something here.

However, the green hexagon (at bottom of viewfinder) only very briefly lights up at the same exact time that the tiny square dot (in center of viewfinder) lights up and goes off (at same time as momentary beep)....

Should the green hexagon stay lit while in focus- ?
01-19-2022, 02:17 PM   #21
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QuoteOriginally posted by Michael Piziak Quote
I will have to read up on how to get that hexagon to show up in my live view - just tried live view twice and didn't see it. Must be a menu setting....

Thanks!
Forget the green hexagon, Michael. Seriously, it's not accurate enough. When you focus through the viewfinder, there's actually a surprisingly broad range through which that focus confirmation hexagon will light up. It does not mean you're right on the accurate focus distance - it just means you're close... and that's fine if you're shooting a wide, normal or even short tele lens at moderate apertures, because the depth-of-field will ensure your target is "sharp enough" (though not necessarily as sharp as it could be). With very fast or long manually-focused lenses, Live View - especially when magnified - allows you to see how in-or-out-of-focus your subject is. You need to learn to judge that, rocking the focus ring gently back and forth until you see the sharpest possible image on the screen. Then you're ready to hit the shutter button
01-19-2022, 02:22 PM - 1 Like   #22
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QuoteOriginally posted by BigMackCam Quote
Forget the green hexagon, Michael. Seriously, it's not accurate enough. When you focus through the viewfinder, there's actually a surprisingly broad range through which that focus confirmation hexagon will light up. It does not mean you're right on the accurate focus distance - it just means you're close... and that's fine if you're shooting a wide, normal or even short tele lens at moderate apertures, because the depth-of-field will ensure your target is "sharp enough" (though not necessarily as sharp as it could be). With very fast or long manually-focused lenses, Live View - especially when magnified - allows you to see how in-or-out-of-focus your subject is. You need to learn to judge that, rocking the focus ring gently back and forth until you see the sharpest possible image on the screen. Then you're ready to hit the shutter button
ok. I've had enough of it for today, but I will take some more shots tomorrow with Live View, magnifying in, and getting the best in focus as I can get. I will also set the tripod up, instead of using the table, and use my remote....

01-19-2022, 02:39 PM   #23
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The green hexagon will "light" at different focus distance scale readings on the lens, depending on whether you focus from infinity or close to the object distance; in other words the green hexagon is lit within a "band" of focus- not
at just a single distance/point.

I see focus differences in the pictures, but also it seems the Pentax is generally "sharper".
01-19-2022, 02:48 PM   #24
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QuoteOriginally posted by Michael Piziak Quote
I will have to read up on how to get that hexagon to show up in my live view - just tried live view twice and didn't see it. Must be a menu setting....

Thanks!
Sorry. No. Not in live view. But same is true of red points. Those only show in viewfinder mode.

In liveview I recommend magnified view for manual focus lenses.

---------- Post added 01-19-22 at 04:51 PM ----------

Just read on and you realized that. Lol. I agree that green hexagon is only a broad focus indicator but yes it needs to stay lit up as long as your still pressing the focus button. That’s a minimum. However at f8 it will struggle and it isn’t super pinpoint accurate that’s why I recommended the magnified live view.
01-19-2022, 04:46 PM   #25
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QuoteOriginally posted by Michael Piziak Quote
However, the green hexagon (at bottom of viewfinder) only very briefly lights up at the same exact time that the tiny square dot (in center of viewfinder) lights up and goes off (at same time as momentary beep)....

Should the green hexagon stay lit while in focus- ?
On my KP, when I manually focus through the viewfinder, the red focus indicator will light up when it gets focus.
At the same time, the green hexagon lights up.
The red indicator only lights up for a moment, and the beep happens if it's on, then it goes off until it loses then catches focus again (whether because I've moved or the subject has, or because I've pressed the shutter button again).
The green hexagon stays on as long as I stay on the same focused thing.

-Eric
01-19-2022, 05:09 PM   #26
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QuoteOriginally posted by TwoUptons Quote
On my KP, when I manually focus through the viewfinder, the red focus indicator will light up when it gets focus.
At the same time, the green hexagon lights up.
The red indicator only lights up for a moment, and the beep happens if it's on, then it goes off until it loses then catches focus again (whether because I've moved or the subject has, or because I've pressed the shutter button again).
The green hexagon stays on as long as I stay on the same focused thing.

-Eric
Interesting, my green hexagon seems to have a mind of it's own, acting different with each lens.


I use the AF button on the back for "focus lock" for automatic lens instead of pressing shutter half way down. Seems like sometimes my back button needs to be pushed before the green hexagon will engage. And on the Tamron 500mm manual lens, it's kinda unpredictable... Maybe I just need to read and learn more about the green hexagon - how it acts, when it acts, and if it acts differently for automatic vs. manual lens, etc... I dunno...

Update: I found it in my k-s2 manual, the green hexagon is called the "focus indicator" and seems to be in instructions when using "AF" lens and having the dial on "Auto" & half pressing the shutter button. It's only mentioned once in the entire manual.... (pg. 40 of Users Guide or pg. 27 of Start Guide for k-s2)

Last edited by Michael Piziak; 01-19-2022 at 05:45 PM.
01-19-2022, 06:22 PM - 1 Like   #27
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QuoteOriginally posted by BigMackCam Quote
Forget the green hexagon, Michael. Seriously, it's not accurate enough. When you focus through the viewfinder, there's actually a surprisingly broad range through which that focus confirmation hexagon will light up. It does not mean you're right on the accurate focus distance - it just means you're close... and that's fine if you're shooting a wide, normal or even short tele lens at moderate apertures, because the depth-of-field will ensure your target is "sharp enough" (though not necessarily as sharp as it could be). With very fast or long manually-focused lenses, Live View - especially when magnified - allows you to see how in-or-out-of-focus your subject is. You need to learn to judge that, rocking the focus ring gently back and forth until you see the sharpest possible image on the screen. Then you're ready to hit the shutter button
I have done some reading of photo pages and 2 forum posts on the "focus indicator" and concluded you're right. The green hexagon ("focus indicator") is not accurate enough, and can vary between lens - and especially in my case from AF lens to MF lens. It seems to work very well with automatic lens, works ok from with my manual focus lens (of which are 2 Pentax macro lens), and works the worst with this Tamron f8 lens (green hexagon won't stay on - only gives a blip).

I will practice focusing the Tamron with Live View and magnifying in tomorrow....

Last edited by Michael Piziak; 01-19-2022 at 06:59 PM.
01-19-2022, 09:12 PM   #28
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A 500mm mf lens will require that you turn the focus ring quite slowly to get the focus precise, and precise focus(due to shallow depth of field) is when the green hexagon will light up!

At f8 the focus indicator will require a very precise focus AND a fairly contrasty subject, and may not lock at all; so do try the magnified live view.
01-20-2022, 05:24 AM   #29
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That's pretty consistent with my own results. I used both the 55-300 and the Tamron for moon shots. My copy of the Tamron seems to be slightly sharper than yours, but after cropping it's not better than the 55-300.
I still use the Tamron because it has FF coverage, balances better, and allows for inexpensive 30.5mm rear filters (it's quite trivial to convert a 1.25" astro filter to 30.5mm).
01-20-2022, 08:37 AM   #30
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I'm at it again. This time with tripod, 3 second shutter delay to eliminate shake. Both images taken at ISO 800 & F8. Distance ~ 55 yards. Click on any image to go to Flickr to see EXIF & also the original photos.

Tamron - cropped & auto levels in post


Pentax 55-300 cropped & auto levels in post



Seems like, again, the Tamron focus can't be perfectly nailed (even used live view and magnification of it)


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