Fa35/2 ca?

wildman · 01-23-2017, 05:26 AM

Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel.
Can't explain what went wrong but it's never happened with my FA 35. Something else besides CA went wrong in my opinion.

Last edited by wildman; 01-26-2017 at 04:15 PM.

Na Horuk · 01-23-2017, 06:28 AM

Originally posted by wildman

Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel.

I think the second photo looks too blue-green. To me the top photo looks more like what I would expect around twilight, just after sunset
AutoWB or CTE WB can cause things like that. The camera color profile is another possible culprit.
Either way, if you want to test for color cast, I recommend you photograph some stationary grey objects in natural daylight, with no windows or filters between.

To me, even the OP photo does not look too bad. Did you shoot raw and PP the photo, or is that in-cam jpeg?
My pointers are:
a) try lower ISO, or better NR
b) add more sharpening. Some cameras add sharpening automatically, even to "raw" files
c) Play with the WB. Remember that if you shoot golden hour or blue hour, it doesn't make sense to combat the natural light. Instead of trying to neutralize the sunset (or sunrise, or total shadow), you should use it as part of the shot
d) I think part of the problem is the DoF. 35mm at f5 on APSC camera has relatively shallow DoF. For me, it is too shallow for landscapes. I take 35mm landscapes at f7.1 or f8.

Thing is, each new lens has some learning curve. You may not realize it, but its true. Handle that lens some more and you will get better results from it.

For real sharpness and CA tests, take photos of closeup subjects in bright natural sunlight. This will show you if there is decentering or other such problems. The lens turbo should make photos look better, because it compresses them to a smaller image circle, which makes CA disappear and details show up more. At least, that is what I heard about that tool, I don't have experience with it

butangmucat · 01-23-2017, 07:45 AM

Originally posted by stevebrot

#1 has sharpest focus on the wires at top and nearest track at bottom and is degraded as the wire runs towards the train. Not knowing your technique or AF point used, it is hard to say why. FWIW, I use my copy of the FA 35/2 with no AF fine adjustments on my K-3 (SAFOX XI).

Steve

Because I have been shooting MF for most of the time and this is my first fast normal prime with AF (the FA35 is intended to replace my Super-Takumar 35/2 for use on DSLR) so I left with the default setting of my K-S2 which worked rather well with my DA20-40: AF-A with auto 11 points. This setting seems to produce good results with my FA35 for stationary objects, but for moving objects it tends to produce acceptable but not nailed focus. I did not add any sharpening for #1. I used TAv for a 1/1000 shutter speed to be on the safe side and a f5 aperture which my experience from other MF lenses tells me to have a rather good DOF.

The FA35 was a recent purchase, and I shot the same scene with FA43 and Lens Turbo for the reason that I know this combo rather well, to serve as a backup for the FA35 that I am not familiar with.

---------- Post added 01-23-17 at 07:48 AM ----------

Originally posted by Na Horuk

I think the second photo looks too blue-green. To me the top photo looks more like what I would expect around twilight, just after sunset
AutoWB or CTE WB can cause things like that. The camera color profile is another possible culprit.
Either way, if you want to test for color cast, I recommend you photograph some stationary grey objects in natural daylight, with no windows or filters between.

To me, even the OP photo does not look too bad. Did you shoot raw and PP the photo, or is that in-cam jpeg?
My pointers are:
a) try lower ISO, or better NR
b) add more sharpening. Some cameras add sharpening automatically, even to "raw" files
c) Play with the WB. Remember that if you shoot golden hour or blue hour, it doesn't make sense to combat the natural light. Instead of trying to neutralize the sunset (or sunrise, or total shadow), you should use it as part of the shot
d) I think part of the problem is the DoF. 35mm at f5 on APSC camera has relatively shallow DoF. For me, it is too shallow for landscapes. I take 35mm landscapes at f7.1 or f8.

Thing is, each new lens has some learning curve. You may not realize it, but its true. Handle that lens some more and you will get better results from it.

For real sharpness and CA tests, take photos of closeup subjects in bright natural sunlight. This will show you if there is decentering or other such problems. The lens turbo should make photos look better, because it compresses them to a smaller image circle, which makes CA disappear and details show up more. At least, that is what I heard about that tool, I don't have experience with it

I used TAv for a 1/1000 f5 combo, and shot raw which I ran through Affinity Photo. I left the in-camera WB to be CTE and did not add sharpening, but used rather aggressive NR as I did pull the shadow a lot.

stevebrot · 01-23-2017, 10:15 AM

Originally posted by butangmucat

AF-A with auto 11 points. This setting seems to produce good results with my FA35 for stationary objects, but for moving objects it tends to produce acceptable but not nailed focus.

The camera locked on the best focus available...i.e. something stationary. In this case, it was something several meters in front of the train. That is how AF-A, Auto 11 works.

Steve

stevebrot · 01-23-2017, 10:18 AM - **1 Like**

Originally posted by wildman

Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel.
Can't explain what went wrong but it's never happened with my FA 35. Something else besides CA went wrong in my opinion.

The photo was taken with the sun low and the light was not full spectrum. The red cast is because there was little blue. Part of the red on the wires is simply reflection...at least that is my interpretation.

Steve

butangmucat · 01-23-2017, 10:19 AM

Originally posted by stevebrot

The camera locked on the best focus available...i.e. something stationary. In this case, it was something several meters in front of the train. That is how AF-A, Auto 11 works.

Steve

But at f/5, the DOF should be able to save the day... right?

stevebrot · 01-23-2017, 10:42 AM - **1 Like**

Originally posted by butangmucat

But at f/5, the DOF should be able to save the day... right?

The DOF for acceptable focus depends on both aperture and focus distance. If the point-of-focus at that aperture had been the front of the train, most of the rest of the train would have been in focus as would much of the foreground. Instead the point-of-focus was at least 5 meters in front of the train with the front being outside the range of acceptable focus. This is clear from the photo.

F/5.0 would have been adequate if the point-of-focus was proper, but sadly, it was not. You might want to consider center-point focus* or manual focus using pre-focus technique.

Steve

* Tell the camera where to focus and it will do a better job of doing so. Some find setting the body up for back-button-only focus along with using a set AF point helps for cases like your photo. Pre-focus at the portion of the frame where you want the front of the train and shoot when the train actually gets there.

01-23-2017, 06:28 AM	#17
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Originally posted by wildman Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel. I think the second photo looks too blue-green. To me the top photo looks more like what I would expect around twilight, just after sunset AutoWB or CTE WB can cause things like that. The camera color profile is another possible culprit. Either way, if you want to test for color cast, I recommend you photograph some stationary grey objects in natural daylight, with no windows or filters between. To me, even the OP photo does not look too bad. Did you shoot raw and PP the photo, or is that in-cam jpeg? My pointers are: a) try lower ISO, or better NR b) add more sharpening. Some cameras add sharpening automatically, even to "raw" files c) Play with the WB. Remember that if you shoot golden hour or blue hour, it doesn't make sense to combat the natural light. Instead of trying to neutralize the sunset (or sunrise, or total shadow), you should use it as part of the shot d) I think part of the problem is the DoF. 35mm at f5 on APSC camera has relatively shallow DoF. For me, it is too shallow for landscapes. I take 35mm landscapes at f7.1 or f8. Thing is, each new lens has some learning curve. You may not realize it, but its true. Handle that lens some more and you will get better results from it. For real sharpness and CA tests, take photos of closeup subjects in bright natural sunlight. This will show you if there is decentering or other such problems. The lens turbo should make photos look better, because it compresses them to a smaller image circle, which makes CA disappear and details show up more. At least, that is what I heard about that tool, I don't have experience with it Last edited by Na Horuk; 01-23-2017 at 07:38 AM.

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01-23-2017, 05:26 AM	#16
wildman Veteran Member Join Date: Jun 2008 Location: Flyover America Posts: 4,469	Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel. Can't explain what went wrong but it's never happened with my FA 35. Something else besides CA went wrong in my opinion. Last edited by wildman; 01-26-2017 at 04:15 PM.

01-23-2017, 07:45 AM	#18
butangmucat Veteran Member Join Date: Jul 2016 Posts: 709 Original Poster	Originally posted by stevebrot #1 has sharpest focus on the wires at top and nearest track at bottom and is degraded as the wire runs towards the train. Not knowing your technique or AF point used, it is hard to say why. FWIW, I use my copy of the FA 35/2 with no AF fine adjustments on my K-3 (SAFOX XI). Steve Because I have been shooting MF for most of the time and this is my first fast normal prime with AF (the FA35 is intended to replace my Super-Takumar 35/2 for use on DSLR) so I left with the default setting of my K-S2 which worked rather well with my DA20-40: AF-A with auto 11 points. This setting seems to produce good results with my FA35 for stationary objects, but for moving objects it tends to produce acceptable but not nailed focus. I did not add any sharpening for #1. I used TAv for a 1/1000 shutter speed to be on the safe side and a f5 aperture which my experience from other MF lenses tells me to have a rather good DOF. The FA35 was a recent purchase, and I shot the same scene with FA43 and Lens Turbo for the reason that I know this combo rather well, to serve as a backup for the FA35 that I am not familiar with. ---------- Post added 01-23-17 at 07:48 AM ---------- Originally posted by Na Horuk I think the second photo looks too blue-green. To me the top photo looks more like what I would expect around twilight, just after sunset AutoWB or CTE WB can cause things like that. The camera color profile is another possible culprit. Either way, if you want to test for color cast, I recommend you photograph some stationary grey objects in natural daylight, with no windows or filters between. To me, even the OP photo does not look too bad. Did you shoot raw and PP the photo, or is that in-cam jpeg? My pointers are: a) try lower ISO, or better NR b) add more sharpening. Some cameras add sharpening automatically, even to "raw" files c) Play with the WB. Remember that if you shoot golden hour or blue hour, it doesn't make sense to combat the natural light. Instead of trying to neutralize the sunset (or sunrise, or total shadow), you should use it as part of the shot d) I think part of the problem is the DoF. 35mm at f5 on APSC camera has relatively shallow DoF. For me, it is too shallow for landscapes. I take 35mm landscapes at f7.1 or f8. Thing is, each new lens has some learning curve. You may not realize it, but its true. Handle that lens some more and you will get better results from it. For real sharpness and CA tests, take photos of closeup subjects in bright natural sunlight. This will show you if there is decentering or other such problems. The lens turbo should make photos look better, because it compresses them to a smaller image circle, which makes CA disappear and details show up more. At least, that is what I heard about that tool, I don't have experience with it I used TAv for a 1/1000 f5 combo, and shot raw which I ran through Affinity Photo. I left the in-camera WB to be CTE and did not add sharpening, but used rather aggressive NR as I did pull the shadow a lot.

01-23-2017, 10:15 AM	#19
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by butangmucat AF-A with auto 11 points. This setting seems to produce good results with my FA35 for stationary objects, but for moving objects it tends to produce acceptable but not nailed focus. The camera locked on the best focus available...i.e. something stationary. In this case, it was something several meters in front of the train. That is how AF-A, Auto 11 works. Steve

01-23-2017, 10:18 AM - 1 Like	#20
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by wildman Before and after a PF correction and it still had a strong red cast overall that I corrected a bit by desaturating the red channel. Can't explain what went wrong but it's never happened with my FA 35. Something else besides CA went wrong in my opinion. The photo was taken with the sun low and the light was not full spectrum. The red cast is because there was little blue. Part of the red on the wires is simply reflection...at least that is my interpretation. Steve

01-23-2017, 10:19 AM	#21
butangmucat Veteran Member Join Date: Jul 2016 Posts: 709 Original Poster	Originally posted by stevebrot The camera locked on the best focus available...i.e. something stationary. In this case, it was something several meters in front of the train. That is how AF-A, Auto 11 works. Steve But at f/5, the DOF should be able to save the day... right?

01-23-2017, 10:42 AM - 1 Like	#22
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by butangmucat But at f/5, the DOF should be able to save the day... right? The DOF for acceptable focus depends on both aperture and focus distance. If the point-of-focus at that aperture had been the front of the train, most of the rest of the train would have been in focus as would much of the foreground. Instead the point-of-focus was at least 5 meters in front of the train with the front being outside the range of acceptable focus. This is clear from the photo. F/5.0 would have been adequate if the point-of-focus was proper, but sadly, it was not. You might want to consider center-point focus* or manual focus using pre-focus technique. Steve * Tell the camera where to focus and it will do a better job of doing so. Some find setting the body up for back-button-only focus along with using a set AF point helps for cases like your photo. Pre-focus at the portion of the frame where you want the front of the train and shoot when the train actually gets there.