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02-13-2013, 02:51 PM   #16
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QuoteOriginally posted by Laurentiu Cristofor Quote
Yes, I guess I had my scenarios in mind more than yours. My "focus challenge scenario" is available light portraiture and in that scenario, with thin DOF it makes a difference if you focus on the eye or on the brow - the focusing point can often overlap both, as it is not easy to keep it just over the eye if the subject is moving . This is also where focus peaking was failing - it was highlighting both the pupil and the brow and the highlight over the pupil was not easy to notice either.

Very nice work! I never had a lens that is suitable for this scenario. Speaking of lenses, which Pentax lens would you plan to use for such work?
Hi, thanks.

Yep, that's why I included the samples, it's normal that when we're giving an opinion we're thinking in our own situations.

I understand your point about peaking, that's also why I said before that in it's current state I can't use it for action, or I can but not so well as trap focus.

BTW your experience with peaking is with Sony or Pentax? IMO both systems has it's strong points and weaknesses, but I think Pentax is probably better for your use.
In theory (because I never tried it), I'm not so fond of Pentax because of the lack of color choice, in fast action I think it would be difficult to notice Pentax peaking. But I think it's a more sensitive and precise peaking than Sony, because unlike Sony it appears to work in both vertical and horizontal axis.

I wont be using a lens, I'll be using a telescope. It's what I've been using for a long time, a 480mm F/6 triplet apochromatic telescope. The IQ of this thing is really good, and that's in part why I refuse to use AF systems, it's hard to find an AF lens that can keep up with the optical quality of this scope, at least at a reasonable price And with a body that can give me realible CIF I don't see the need to have AF.

02-15-2013, 09:26 PM   #17
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QuoteOriginally posted by FernandoBatista Quote
BTW your experience with peaking is with Sony or Pentax? IMO both systems has it's strong points and weaknesses, but I think Pentax is probably better for your use.
Sony only. A colleague purchased a NEX and showed it to me. We played with a Takumar 50/1.4 lens. It might have been the F3 model - I assume there are no differences between models, but I may be wrong.

QuoteOriginally posted by FernandoBatista Quote
I wont be using a lens, I'll be using a telescope. It's what I've been using for a long time, a 480mm F/6 triplet apochromatic telescope. The IQ of this thing is really good, and that's in part why I refuse to use AF systems, it's hard to find an AF lens that can keep up with the optical quality of this scope, at least at a reasonable price And with a body that can give me realible CIF I don't see the need to have AF.
Wow, that telescope sounds interesting. Is it something still being produced or an older lens? I use catadioptric lenses and tried them with birds, but mine are slow (the fastest was f/8) and I can only get decent results on sunny days. And only on static subjects - I cannot rotate those large focusing rings fast enough for BIF. I actually have a modern 300/6.3 mirror lens, but I did not get to try it yet on birds - it's an MFT lens, so it's similar to a 400mm on APS-C. I used the large ones mostly for the exercise of hand helding and focusing with long focal lengths
02-17-2013, 07:44 AM - 1 Like   #18
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QuoteOriginally posted by Laurentiu Cristofor Quote
Sony only. A colleague purchased a NEX and showed it to me. We played with a Takumar 50/1.4 lens. It might have been the F3 model - I assume there are no differences between models, but I may be wrong.
I think it's the same in all Sonys (Nex or Alpha). But Pentax is a bit different, I'd love to try one for myself.

QuoteOriginally posted by Laurentiu Cristofor Quote
Wow, that telescope sounds interesting. Is it something still being produced or an older lens? I use catadioptric lenses and tried them with birds, but mine are slow (the fastest was f/8) and I can only get decent results on sunny days. And only on static subjects - I cannot rotate those large focusing rings fast enough for BIF. I actually have a modern 300/6.3 mirror lens, but I did not get to try it yet on birds - it's an MFT lens, so it's similar to a 400mm on APS-C. I used the large ones mostly for the exercise of hand helding and focusing with long focal lengths
The telescope is a recent model with about three years in the market. There's several brands selling the exact same scope (orion, TS, APM, etc), I have the TS version:
Teleskop-Express: TS 80/480mm F/6 Triplet APO - FPL-53 - Kein Farbfehler

A scope like this is a very different animal than a CAT, it has far more contrast, better resolution, much bigger light transmission and also a superb bokeh. And in use it's much easier to focus too.
Mine is a bit modified, I made my own adapter with an iris and nikon chip (now sony), and other mods. Here's an old photo from mine, currently I made some other mods yet, but I have no recent photos from it.

http://photos.smugmug.com/photos/i-c7p46wn/0/O/i-c7p46wn.jpg

There's others scopes at cheaper prices that can also be a good choice, my usual top recomendation is the Skywacther ED80, at a cost of about 350 you'll get a tack sharp 600mm prime lens. I used one myself for years, opticaly is great, only downside is somewhat inferior mechanics, but definitely worth the cost.
02-18-2013, 09:05 PM   #19
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QuoteOriginally posted by FernandoBatista Quote
A scope like this is a very different animal than a CAT, it has far more contrast, better resolution, much bigger light transmission and also a superb bokeh. And in use it's much easier to focus too.
Mine is a bit modified, I made my own adapter with an iris and nikon chip (now sony), and other mods. Here's an old photo from mine, currently I made some other mods yet, but I have no recent photos from it.

http://photos.smugmug.com/photos/i-c7p46wn/0/O/i-c7p46wn.jpg

There's others scopes at cheaper prices that can also be a good choice, my usual top recomendation is the Skywacther ED80, at a cost of about 350 you'll get a tack sharp 600mm prime lens. I used one myself for years, opticaly is great, only downside is somewhat inferior mechanics, but definitely worth the cost.
I never considered such telescopes for digital photography - I assumed that their optics may not be that good for high resolution sensors, but it looks like I was wrong. Thanks for the tip - I'll look closer into this option!

02-25-2013, 01:46 AM   #20
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My CIF BIFs

QuoteOriginally posted by FernandoBatista Quote

BTW, just to give an idea, this is what I usually shoot:
http://fernandobatista.smugmug.com/Galeria/Aves-Birds/i-KtzjLqK/0/O/2012_03_03_1.jpg

http://fernandobatista.smugmug.com/Galeria/Aves-Birds/i-WvvxLrP/0/O/2011_11_27_5.jpg

http://fernandobatista.smugmug.com/Galeria/Aves-Birds/i-n6GpQ7G/0/O/2011_04_23_1.jpg

http://fernandobatista.smugmug.com/Galeria/Aves-Birds/i-4SgqVbv/0/O/2011_04_16_1.jpg


Doing images like this with the D90 was almost as easy as any AF lens, or even easier in some points... but doing it without the help of a reliable trapfocus, no matter how good the viewfinder or peaking, is just something I'm not seeing happening.
Wonderful pictures! I've just started with a long manual lens (Sigma 400mm f/5.6 APO) and CIF on my K5, and find it a lot more manageable than I expected, even for BIFs. Focus is very precise. If you have long lens faster than f/5.6, the K5ii(s) might be a better idea, as it has f/2.8 AF sensors rather than f/5.6 on the K5 & K30. I still don't have a picture of a bird flying right at me like your cormorant, but here are some seagulls which were flying quite fast.

Luckily, my Sigma 400 needed no front/back focus correction. If a manual lens needs this, the only way to do it (to my knowledge) is to change the global F/B AF microadjustment correction setting when using the specific lens. I've been grumbling about this, as I have a few good A primes that could use AF correction. A firmware update could do the trick.

Regards,
Miles
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02-25-2013, 05:13 AM   #21
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QuoteOriginally posted by miles Quote
Wonderful pictures! I've just started with a long manual lens (Sigma 400mm f/5.6 APO) and CIF on my K5, and find it a lot more manageable than I expected, even for BIFs. Focus is very precise. If you have long lens faster than f/5.6, the K5ii(s) might be a better idea, as it has f/2.8 AF sensors rather than f/5.6 on the K5 & K30. I still don't have a picture of a bird flying right at me like your cormorant, but here are some seagulls which were flying quite fast.

Luckily, my Sigma 400 needed no front/back focus correction. If a manual lens needs this, the only way to do it (to my knowledge) is to change the global F/B AF microadjustment correction setting when using the specific lens. I've been grumbling about this, as I have a few good A primes that could use AF correction. A firmware update could do the trick.

Regards,
Miles
These look very promising Miles, well done. And thank you for your thoughts too.

About the AF sensors, I don't have much need for 2.8 sensors, at least not for this use, the fastest lens I use is a 300mm F4.5 and mostly it would have a TC on it.

My main doubt is still how precise is Pentax CIF with long teles at about F5.6. Does CIF only alow the camera to take the image when it's within DOF, or is there a bigger "tolerance" and it still takes the image when the focus point is already outside DOF (even if it's only by a very little bit)?
This is the main difference between my D90 and the D7000, and what rendered the D7000 useless for my use. How is it with Pentax?
02-25-2013, 12:55 PM   #22
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QuoteOriginally posted by FernandoBatista Quote
These look very promising Miles, well done. And thank you for your thoughts too.

About the AF sensors, I don't have much need for 2.8 sensors, at least not for this use, the fastest lens I use is a 300mm F4.5 and mostly it would have a TC on it.

My main doubt is still how precise is Pentax CIF with long teles at about F5.6. Does CIF only alow the camera to take the image when it's within DOF, or is there a bigger "tolerance" and it still takes the image when the focus point is already outside DOF (even if it's only by a very little bit)?
This is the main difference between my D90 and the D7000, and what rendered the D7000 useless for my use. How is it with Pentax?

I've never used the Nikons, so i can't compare with them... My experience with the Pentax and Sigma 400 f/5.6 is that focus is spot on every time. It will only fire with the subject in focus if set up correctly. It also works very well with my A* 200mm f/4 macro. As expected, my 50mm f/1.2 is much less precise, especially in incandescent light, plus it needs micro-focus adjustment. Hopefully a future K3 will fix this. I wish i could help more...
03-01-2013, 04:26 AM   #23
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QuoteOriginally posted by FernandoBatista Quote
These look very promising Miles, well done. And thank you for your thoughts too.

About the AF sensors, I don't have much need for 2.8 sensors, at least not for this use, the fastest lens I use is a 300mm F4.5 and mostly it would have a TC on it.

My main doubt is still how precise is Pentax CIF with long teles at about F5.6. Does CIF only alow the camera to take the image when it's within DOF, or is there a bigger "tolerance" and it still takes the image when the focus point is already outside DOF (even if it's only by a very little bit)?
This is the main difference between my D90 and the D7000, and what rendered the D7000 useless for my use. How is it with Pentax?
I was taking some macro pics today with the A* 200mm f/4 macro. I took some pictures with the lens wide open, to test CIF accuracy for you. This is a VERY sharp lens, even wide open at 1:1 magnification, and so extremely unforgiving when it comes to focusing error. (=1mm is WAY off). The K5 CIF fired when focus was exactly right.

Note however that only the central AF point works with CIF. Not sure how it is with Nikon.

03-01-2013, 07:24 AM   #24
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Hi Miles,

Thank you for taking the time to test this for me, that's very good to know, Pentax CIF is indeed looking as the best replacement for my D90 trap focus.

But I though CIF worked with all the AF points in the newest bodies...I'm pretty sure I read this somewhere, am I mistaken?

With Nikon, trap focus would work with every point, but remember that Nikon doesn't offer trapfocus natively, it works by using a chip that simulates an AF lens. With that chip, as far as the camera knows it's using an AF lens so it works as it would have a lens, except it doesn't AF by itself.
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