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One More Time (Damn The Torpedoes)
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Apr 24, 2021 14:02:40   #
Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)
 
cameraf4 wrote:
You did read that I focused manually, right? I turned off Auto Focus and I "eyeballed" focus in the viewfinder and used the Focus Assist lights in the viewfinder to guide me. I think next time I'll use my 105mm Micro Nikkor and fill-the-frame as Paul suggested. Maybe that will show me something.


Using the focus assist indicator is not a guarantee that the image will be in focus. It only tells you that the camera thinks it is in focus. In reality if there is a calibration issue, it will not reveal front or back focus. That is why live view, which uses image contrast at the sensor plane, will always be more accurate. In fact, one of simplest tests for focus errors is to use live view to focus, then use the phase detect AF to focus. Understandably there will be some that are in better focus than others using PDAF, but they should be very close to the live view image(s). If they are not, then there is something wrong between the camera and the lens.

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Apr 24, 2021 14:05:39   #
SteveHmeyer Loc: Cincinnati OH USA
 
Gene51 wrote:
...But to be fair they should be compared at similar resolution.


Yes - no post anything on the test images - be sure the target occupies the same percentage of the area of each sensor. That means a closer target-to-sensor distance for larger sensors so the image is the same size in the viewfinder for each sensor.

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Apr 24, 2021 15:14:35   #
JohnR Loc: The Gates of Hell
 
Rongnongno wrote:
There is indeed a sharpness issue.
To solve it, just use live view and manual focus after magnifying on the target.

This is a good effort to show something of interest for those who have one of the cameras used, the lack of focus destroyed it.

Too many so-called tests are made in a lab do they do not reflect the reality of every day use.

Try one more time, please.
When you do...
Use the same lens as it is important when comparing sensors ability to resolve lines.
Solve the focus issue
Do not crop and post
Post as PNG 8 (small files)
Ideally post raw test files and link them to your post after uploading them somewhere else.

Good luck

I wish I could be more positive.

I understand the "Damn the torpedoes"... You cannot dodge them in a forum...
There is indeed a sharpness issue. br To solve it,... (show quote)


Helpful and polite with it. It would be nice if all Hoggers replied to posts in this manner. Thanks Mate.

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Apr 24, 2021 17:51:32   #
SuperflyTNT Loc: Manassas VA
 
Gene51 wrote:
Not if you are trying to compare similarly sized images - apples to apples. I suppose that you could upsample the lower res images as well - or pick something in the middle like 20 or 24 mp. But to be fair they should be compared at similar resolution.


The point was testing sensors. Nobody said anything about similarly sized images. As the OP said, “ Which camera will produce the sharpest images.”. The only way to do that is look at every camera at its highest resolution.

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Apr 24, 2021 19:27:15   #
Architect1776 Loc: In my mind
 
CHG_CANON wrote:
Why 1100x700 ish pixels for the examples? Did you look at these full screen? Honestly, I don't think any of them are in focus. Before cropping / resizing, did they seem in focus on your monitor?

I don't see the lens reported. From the distance shot, is that trying to say you the cropped the chart from that distance? Or, did you run your test with a lens set to a position / focal length to fill the sensor? If these are to show the cropping options, you might consider Rongnongno's recent comment about cropping in post instead of getting closer. Robert Capa had some thoughts about getting closer too.

You might consider the ideas presented here: How to obtain sharp images in digital photography
Why 1100x700 ish pixels for the examples? Did you ... (show quote)



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Apr 24, 2021 22:42:01   #
DaveyDitzer Loc: Western PA
 
Rongnongno wrote:
There is indeed a sharpness issue.
To solve it, just use live view and manual focus after magnifying on the target.

This is a good effort to show something of interest for those who have one of the cameras used, the lack of focus destroyed it.

Too many so-called tests are made in a lab do they do not reflect the reality of every day use.

Try one more time, please.
When you do...
Use the same lens as it is important when comparing sensors ability to resolve lines.
Solve the focus issue
Do not crop and post
Post as PNG 8 (small files)
Ideally post raw test files and link them to your post after uploading them somewhere else.

Good luck

I wish I could be more positive.

I understand the "Damn the torpedoes"... You cannot dodge them in a forum...
There is indeed a sharpness issue. br To solve it,... (show quote)


I believe OP stated he or she used the same lens: Nikon 85mm F1.8 D

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Apr 24, 2021 22:49:35   #
DaveyDitzer Loc: Western PA
 
Gene51 wrote:
Good idea, but, to eliminate more variables, you may want to try shooting raw, using a spot meter on a grey card target, and using only live view for focusing. This removes exposure variations, focus anomalies and makes the test more informative. Also, in processing the files, reduce the image size to 12 mp, which will mean that all higher mp cameras will be downsampled to the same as the D700.


Gene,
Please help me here. Isn't part of the comparison to compare senors using the same lens? If I downsize the image to, e.g., 12mp, doesn't that negate the goal of comparing sensors?

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Apr 25, 2021 03:54:31   #
SuperflyTNT Loc: Manassas VA
 
DaveyDitzer wrote:
Gene,
Please help me here. Isn't part of the comparison to compare senors using the same lens? If I downsize the image to, e.g., 12mp, doesn't that negate the goal of comparing sensors?


Exactly

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Apr 25, 2021 04:39:58   #
Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)
 
SteveHmeyer wrote:
Yes - no post anything on the test images - be sure the target occupies the same percentage of the area of each sensor. That means a closer target-to-sensor distance for larger sensors so the image is the same size in the viewfinder for each sensor.


These are all FX sensors.

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Apr 25, 2021 05:10:06   #
Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)
 
DaveyDitzer wrote:
Gene,
Please help me here. Isn't part of the comparison to compare senors using the same lens? If I downsize the image to, e.g., 12mp, doesn't that negate the goal of comparing sensors?


Not at all. Doing an digital comparison (on screen) of an image from a 12 mp camera to one from a 46 mp camera means you are comparing a relatively small image to a huge one. Make them the same size, then size is not an issue. The high mp camera will still come out ahead.

When you print at the same resolution, the difference is even more pronounced. At 300 ppi, a 12 mp image would be 14.19" x 9.44" and the 45 mp image at the same resolution would be 27.52" x 19.35" which would not make for a good comparison. Having the two prints at the same resolution and the same size would be a good comparison. On screen, having the two images at the same spatial resolution would make for a better comparison as well.

Here are a few articles that may help inform your opinion:

https://photographylife.com/camera-resolution-explained

https://photographylife.com/the-benefits-of-a-high-resolution-sensor




-

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Apr 25, 2021 05:11:48   #
Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)
 
DaveyDitzer wrote:
Gene,
Please help me here. Isn't part of the comparison to compare senors using the same lens? If I downsize the image to, e.g., 12mp, doesn't that negate the goal of comparing sensors?


[deleted]

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Apr 25, 2021 09:57:38   #
cameraf4 Loc: Delaware
 
Gene51 wrote:
Not at all. Doing an digital comparison (on screen) of an image from a 12 mp camera to one from a 46 mp camera means you are comparing a relatively small image to a huge one. Make them the same size, then size is not an issue. The high mp camera will still come out ahead.

When you print at the same resolution, the difference is even more pronounced. At 300 ppi, a 12 mp image would be 14.19" x 9.44" and the 45 mp image at the same resolution would be 27.52" x 19.35" which would not make for a good comparison. Having the two prints at the same resolution and the same size would be a good comparison. On screen, having the two images at the same spatial resolution would make for a better comparison as well.

Here are a few articles that may help inform your opinion:

https://photographylife.com/camera-resolution-explained

https://photographylife.com/the-benefits-of-a-high-resolution-sensor




-
Not at all. Doing an digital comparison (on screen... (show quote)


Must be too early on a Sunday for me but both of these articles gave me a headache and very little understanding. Let's cut to the chase. Let's say that you, Gene, have a 12MP image before you and a 46MP image of the same subject. When you "make them the same size" would you simply resample the larger image to the same number of pixels as the smaller image along the horizontal axis with "resample image" enabled? My fuzzy head this morning is saying "Yes".

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