I guess it comes down to figuring out what those conditions are and when these are present.
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A7R4, A7R IV - Not resolving detail
- Thread starter DanD_NZ
- Start date
jan pawlak
Leading Member
So matrix. and optics are ok.
Try setting the camera to continuous shooting, AF-C and f/8 for the set. Take a series of several photos
When you set the autofocus to AF-C, you see green focus squares and are they on the birds?
All photos in the series are not sharp?
On all the photos in the series is not a single sharp bird that marked by AF-C was a green square?. GO for 100m is about 13m.
ISO 5000 is not a problem for this camera
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Tomorrow I'll do the new test you suggested. In the mean-time, in answer to your questions, I can confirm that the focus square turns green when the camera has acquired focus. And yes, none of the photos of the geese are sharp enough. All photos of the walking sign are good. Below I included one of each.
View attachment caf4ef8d603c43dba45db4048add1edb.jpg
View attachment d0d68441fa2f4d2fa42c4ce22b91c8d4.jpg
joger
Veteran Member
Even with the best available lenses the air in front of the camera is the limiting factor.
The telescopes from Nasa stand at high altitudes and they use lasers to measure the air turbulence to get rid of unsharp images.
Long Tele plus long distance will cause degradation no matter what conditions - especially at low altitudes - in case you want to test whether you gear works well go indoors in a long building ( airport, Church, sports arena and try again - you'll most probably see a difference.
BTW - the outside temperature is not important - it is the air floating over heat collecting surfaces - as soon as you gut sunshine you'll have this effect - always.
Actually, the phenomenon is not caused by high winds or high temperatures as such but by temperature gradients between different layers of the air which begins to move quietly around. Air of different temperatures refract the light differently, causing the wavy unsharpness in our photos. If anything, I tend to see it happen more often on quiet days than one windy days. I figure strong winds mix up the layers of air efficiently so whatever gradient could have been built up is instantly washed away. Note that it is not only seen in hot weather. It can be seen in arctic climates too. It's the temperature gradient which is important, not the air temperature as such. If I remember correctly, Magnar has previously posted examples of this from his home country Norway.
In your case there is an air temperature of about 20 degrees C. It is likely that the water, seen in abundance in the scene, is considerably colder. Thus with the very light winds the conditions are good for a temperature gradient in the air above the water and the clear air make you see it clearly.
An aside: The refraction of light between lens elements by the air is also important to consider when designing lenses. One of the first versions of the famous Leitz 50mm Summicron had two lens elements with identical curvature on the adjacent surfaces. For that matter they could have been cemented, but they weren't because Included in the design was a narrow distance between the two lens elements and that "air lens" - as it was called - improved the performance of the lens. The result was a lens with a very high resolution for its day. The price to pay for the high resolution was a little lower contrast, but since most people shot B&W back then, it could easily be adjusted in the darkroom, either by increasing the film development time/temperature/agitation slightly or by choosing a more contrasty copy paper.
...... oh, but I digress.
--
"Sharpness is a bourgeois concept." (Henri Cartier-Bresson)
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jan pawlak
Leading Member
Looking at these two pictures you can see that a 2x teleconverter for this lens may not be a good solution. The system aperture for 800mm is already f / 11 which is often in the area of not very good quality of reproduction by the lens. In addition, 800mm is a very small depth of field as seen in the second picture. But some element of the photo should be sharp
Take a serial photo birds test with AF-C without a teleconverter and with a teleconverter. It may turn out that a better solution will be 2x crop from 400mm focal length,
A7R4 has a very large crop potential. The matrix resolution is enough for a very good print with a width of about 95cm
What do you want to present your photos on?
Take a serial photo birds test with AF-C without a teleconverter and with a teleconverter. It may turn out that a better solution will be 2x crop from 400mm focal length,
A7R4 has a very large crop potential. The matrix resolution is enough for a very good print with a width of about 95cm
What do you want to present your photos on?
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dcstep
Senior Member
You're welcome. It's great to see another DxO user. I go back to 2008. It's come a long way.Thanks for that. I am not convinced that there was much, if any, atmospheric distortion. It was a very clear day, very light winds, only about 20 degr C. I could not see any air shimmering. I didn't think that the master G 2x TC would be causing this degree of distortion. With regards to the cormorant, yeah, the ISO went up because I had my shutter speed unnecessarily high at 1/3200. I use DxO Photolab 3.1 for my PP. I raised the shadows to 31 and used Prime noise reduction with default settings. I would try the settings you suggested but there is no DxO module yet for this lens/TC combo.The FE 2.0x teleconverter will reduce detail, but not this badly.
I think that with the mass birds shots, your experiencing atmospheric distortion. It's quite a common issue at focal lengths like 800mm.
With the cormorant, you shot at way too high an ISO. I suspect that your RAW converter's noise reduction, set at default, applied too much luminescence reduction and smashed details. With DxO PhotoLab, I turn the luminescence NR down to 20 and raise Fine Detail to around 10 or 12. The blacks look pretty good here, so I'm wondering if you raised them. They needed to be raised, but it'll aggravate the NR softening issue.
Generally, you'll need to shoot at 800mm when the earth/air temperature ratios are low, OR shoot closer to your subjects.
Always be aware that too much NR kills feather and fur details; however, if you lower default settings for luminescence and raise Fine and Micro contrast (judiciously)
Here's high-ISO, with that same lens, using DxO's incredible PRIME NR, adjusted off its defaults:
Even with DxO PRIME, you need to lower luminescence to 20. Use the Advanced Contrast settings to raise Fine and Micro contrast a bit. I tend to use Clearview at 20 as a default. If you use Clearview, you may need to raise EV a bit.
Here, in Colorado, I shoot a lot out over the water on cool and cold days. I'm not sure why, but the heat waves are often invisible to the naked eye, but show up when I'm using my longest lenses. I think maybe because the layer is not very high, maybe only a few feet, but the magnification of the lens exaggerates it tremendously. Often, the limit is less than 50-yards. I experience this A LOT.
Interesting thought about the DxO modules. You'll see, in my example, that you can get really sharp results without a DxO module. Still, I will often use my 600mm bare, just so I can have access to PhotoLab's "Detail" module, which is an incredibly clean and effective Sharpening tool. If I find my ISO getting up over 1600, I tend to leave the teleconverter off, so that I'll have that added sharpening tool. (I think it's more effective than Topaz's AI Sharpen tool, when it's available.)
--
Dave
some better examples of the fe100-400/2x at the bottom of this link: https://photographylife.com/reviews/sony-fe-2x-teleconverter
I've seen quite a few pics from that combo, that are much better than what the o.p. has been posting, there is something wrong with his situation.
that said, if you want 800mm fov, there are better ways to do it, like the fe200-600/1.4x, or 100-400/1.4x with cropping, as you indicated.
that photo of the walking sign is not what i would call good, but it's a great test target, forget the ducks for now… shoot it square to the camera next time, not at an angle, wide open only.
that shot has been processed in dxo, apparently with a vivid creative style, and no lens correction? need to see ooc jpeg, unedited.
To get the best of your gear :
1. be carreful to not use very high ISO. From far away a 100% crop at 5000 ISO on dark feathers is not an easy job. Then you need to shot raw and to use either DX0 PHotoLAB with its PRIME function or TOPAZ AI DENOISE. Try to stay at low ISO (400 ISO) if you want to crop strongly.
2. be carreful of the temp effect on atmospher. For long distance photo it can destroy the image quality, I had the problem this summer.
1. be carreful to not use very high ISO. From far away a 100% crop at 5000 ISO on dark feathers is not an easy job. Then you need to shot raw and to use either DX0 PHotoLAB with its PRIME function or TOPAZ AI DENOISE. Try to stay at low ISO (400 ISO) if you want to crop strongly.
2. be carreful of the temp effect on atmospher. For long distance photo it can destroy the image quality, I had the problem this summer.
Good thinking. I can go to our local shopping mall or airport for this. Taking test shots in an indoor environment should provide the answers.
Thanks for the clear explanation of what might be happening and the history lessonActually, the phenomenon is not caused by high winds or high temperatures as such but by temperature gradients between different layers of the air which begins to move quietly around. Air of different temperatures refract the light differently, causing the wavy unsharpness in our photos. If anything, I tend to see it happen more often on quiet days than one windy days. I figure strong winds mix up the layers of air efficiently so whatever gradient could have been built up is instantly washed away. Note that it is not only seen in hot weather. It can be seen in arctic climates too. It's the temperature gradient which is important, not the air temperature as such. If I remember correctly, Magnar has previously posted examples of this from his home country Norway.
In your case there is an air temperature of about 20 degrees C. It is likely that the water, seen in abundance in the scene, is considerably colder. Thus with the very light winds the conditions are good for a temperature gradient in the air above the water and the clear air make you see it clearly.
An aside: The refraction of light between lens elements by the air is also important to consider when designing lenses. One of the first versions of the famous Leitz 50mm Summicron had two lens elements with identical curvature on the adjacent surfaces. For that matter they could have been cemented, but they weren't because Included in the design was a narrow distance between the two lens elements and that "air lens" - as it was called - improved the performance of the lens. The result was a lens with a very high resolution for its day. The price to pay for the high resolution was a little lower contrast, but since most people shot B&W back then, it could easily be adjusted in the darkroom, either by increasing the film development time/temperature/agitation slightly or by choosing a more contrasty copy paper.
...... oh, but I digress.
. By the way, I don't know what the temperature was of the water in my photos, however, those are quite shallow so I do not think the water would be very cold at all.For me, it is not so much about what I want to present my photos on. In New Zealand we have many smaller birds that can be some distance away. The focus square often barely covers the bird (seen through the view finder). The idea is that with the A7R IV I should be able to capture lots of detail and then in PP be able to crop up to 200% without losing detail. Here is a photo of a yellow hammer about 10-15m away and taken at 400mm without my TC. (Interestingly, the EXIF data says that the subject distance was 2.78m). Yet, I don't think the detail is there when cropped. Am I being over fussy?
Vibrancy and contrast are both up a little. Unfortunately I shot the photo in RAW only. I'll try some other test shots tomorrow if the weather cooperates.
Looking at the original at 100% you can clearly see the rippled edges of the turbine blades. But given the 26MP sensor in crop mode I suppose this is not a bad result. I would think that the A7R IV would eat this, except, not in my case with the birds (or other subjects for that matter).Clear sunny day with no breeze.
A9 and 100-400 gm lens crop mode so 600mm
original
Again. Many thanks for your response. I will start experimenting with the DxO settings. I do appreciate that atmospheric conditions can affect long lenses. Someone else suggest I try some test shot indoors. That is an excellent idea too. I have some work to the next couple of days and try to keep my ISO down as well.You're welcome. It's great to see another DxO user. I go back to 2008. It's come a long way.Thanks for that. I am not convinced that there was much, if any, atmospheric distortion. It was a very clear day, very light winds, only about 20 degr C. I could not see any air shimmering. I didn't think that the master G 2x TC would be causing this degree of distortion. With regards to the cormorant, yeah, the ISO went up because I had my shutter speed unnecessarily high at 1/3200. I use DxO Photolab 3.1 for my PP. I raised the shadows to 31 and used Prime noise reduction with default settings. I would try the settings you suggested but there is no DxO module yet for this lens/TC combo.The FE 2.0x teleconverter will reduce detail, but not this badly.
I think that with the mass birds shots, your experiencing atmospheric distortion. It's quite a common issue at focal lengths like 800mm.
With the cormorant, you shot at way too high an ISO. I suspect that your RAW converter's noise reduction, set at default, applied too much luminescence reduction and smashed details. With DxO PhotoLab, I turn the luminescence NR down to 20 and raise Fine Detail to around 10 or 12. The blacks look pretty good here, so I'm wondering if you raised them. They needed to be raised, but it'll aggravate the NR softening issue.
Generally, you'll need to shoot at 800mm when the earth/air temperature ratios are low, OR shoot closer to your subjects.
Always be aware that too much NR kills feather and fur details; however, if you lower default settings for luminescence and raise Fine and Micro contrast (judiciously)
Here's high-ISO, with that same lens, using DxO's incredible PRIME NR, adjusted off its defaults:
Even with DxO PRIME, you need to lower luminescence to 20. Use the Advanced Contrast settings to raise Fine and Micro contrast a bit. I tend to use Clearview at 20 as a default. If you use Clearview, you may need to raise EV a bit.
Here, in Colorado, I shoot a lot out over the water on cool and cold days. I'm not sure why, but the heat waves are often invisible to the naked eye, but show up when I'm using my longest lenses. I think maybe because the layer is not very high, maybe only a few feet, but the magnification of the lens exaggerates it tremendously. Often, the limit is less than 50-yards. I experience this A LOT.
Interesting thought about the DxO modules. You'll see, in my example, that you can get really sharp results without a DxO module. Still, I will often use my 600mm bare, just so I can have access to PhotoLab's "Detail" module, which is an incredibly clean and effective Sharpening tool. If I find my ISO getting up over 1600, I tend to leave the teleconverter off, so that I'll have that added sharpening tool. (I think it's more effective than Topaz's AI Sharpen tool, when it's available.)
Thanks heaps for your comment. I will need to keep an eye on my ISO and juggle that with my shutter speed.
That photography link is the one that actually made me comfortable enough to buy the 2x TC for use with my 100-400mm lens.
I assume you mean that I am the o.p. being the originator of this thread?
Do you have any thoughts as to what could be wrong with my combo or what I could be doing wrong?
jan pawlak
Leading Member
This bird should be much sharper.For me, it is not so much about what I want to present my photos on. In New Zealand we have many smaller birds that can be some distance away. The focus square often barely covers the bird (seen through the view finder). The idea is that with the A7R IV I should be able to capture lots of detail and then in PP be able to crop up to 200% without losing detail. Here is a photo of a yellow hammer about 10-15m away and taken at 400mm without my TC. (Interestingly, the EXIF data says that the subject distance was 2.78m). Yet, I don't think the detail is there when cropped. Am I being over fussy?
Under these shooting conditions, the depth of field is about 10 cm before and 10 cm behind the focal point.
Repeat such photos with continuous shooting and AF-C settings and take several photos in series.
Will there be any sharp photos in the series?
--
jan
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