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Sony A7 III sensor testing.

There has been a lot chatter about the A7 mark 3. Both the previous models were excellent low light performers, although there was some discussion in the Astro community they were eating stars. With the introduction of a BSI sensor could this be the camera for you?

Having recently tested the Panasonic S1 I was very interested to see how the A7 III performs, as most people are saying it’s currently a 2 horse race between these two cameras.

Well I happy to say the A7 performs very well, It’s clear that the BSI sensor is much more uniform than previous models and it has significantly less noise.

When comparing it to it’s competition it stacks up very well. It performs very close to the S1, and surprisingly at 5 minutes there is almost nothing in it. The EOS R is the worst of the pack and the A7III is significantly better right across the exposures tested.

I am not sure if the Z6 and the A7III share the same sensor. Getting 100% confirmation on this is very hard, some articles are saying they are the same, while in others the number of raw pixels is slightly different, so maybe they are not. If they are then the 5 minute exposure time could show aggressive NR from Sony. However there have reports that the A7III is not suffering from the star eating problem that previous models had, well not completely it depends on what you read, but it’s better. So you can draw your own conclusions about the Z6 and the A7III sharing the same sensor.

It would be more consistent to conclude the S1 and A7III share the same sensor than the Z6. With many saying this is the case less with only the phase detection pixels removed in the S1. The difference in noise could easily come down to RAW images algorithms, and sensor production variation. It will be interesting to see how the A7RIII and S1R compare.

In my opinion if you currently own Sony gear the upgrade path is a no brainer, the A7III. if you don’t other factors such as cost, lens availability and other camera features are more likely to be a factor if you are leaning to the S1.

It’s also worth noting that ensuring testing temperature is very difficult and this or a future firmware upgrade could easily tip the scales to either the A7III or the S1 or even the Z6. What can be done with a firmware upgrade is amazing. Either way both the A7III and the S1 are excellent long exposure performers and should perform very well.

If you would like to find out more about the Sensor DBclick here.

Fuji X-T3. Third time lucky?

I’m always in two minds when it comes to the fuji sensors. and like Olympus they seem to be doing noise reduction and low level sensor data manipulation even when it’s disabled in camera. It could be the “grain effects” that make Fuji unique, but it does make it hard to compare their sensors to other bodies.

Having said that the new X-T3 performs much better than the X-T2, even with a few more MP. At 1 and 30 seconds the sensor is much better than it’s predecessor. Noise does build up quicker with longer exposures and at five minutes the results are worse (noise mean), but with less standard deviation.

X-T2 vs X-T3

Compared it to the Nikon Z6, currently the leader for long exposure noise the X-T3 appears to do very well. However as mentioned above this in my mind only shows one thing, that Fuji are seriously processing the RAW data. Keep in mind that the X-T3 is a crop body, where as the Z6 is not.

Thats some serious low noise?

When compared to a crop body like the Nikon D7500 you start to get an idea of what is going on:

Nikon D7500 vs X-T3, whats the story here?

There is no doubt that the X-T3 is a big improvement on the previous model, the noise has been greatly reduced. However I am really not sure how this camera will perform in a real world low light situation. Either Fuji have a crop sensor that is performing better than any full frame sensor, or they are performing noise reduction. I think the latter is more likely, and how this impacts on some subject matter like stars I guess time will tell. Some real world astrophotography samples would be great to see.

If you would like to compare the X-T3 to more models, or learn more about the sensor database click here.

Again, a big thanks for Alex @Stallards in Hobart for access to the X-T3.

The Flagship, Canon 1DX Mark II, No. 50!

The Canon 1DX Mark II results are now in the Sensor DB, and it’s our 50th camera to be added. WOW 50. It’s taken a few years, but the list is now becoming quite substantial, giving the community some good insight into the level and treatment of noise.

The results are good and there is a significant improvement at 5 mins compared with the 1Dx, which, I think is reflective of the new ISO range, allowing up to 409600 ISO. There has obviously been a sensor change from 17.9MP in the old model compared to 20.2MP in the new model, with the original 1DX slightly better with noise at 1 and 30 seconds. However the 1DXm2 gives very respectable results, and the difference could easily be attributed to the additional megapixels.

Of course the 1D series of cameras is not intended for astrophotography, and it would be hardly the camera to recommend for that task. But it’s nice to see it’s a solid performer none the less.

Again, a big thank you to Walch Optics for providing access to many of the models we test.

Pushing to +5EV, Pentax K1 & PetaPixel

I have been working hard on the Sensor DB, add new features and models. As part of the process of adding newer and better models I have re-processed all of the samples to +2.5EV and +5EV. This allows the noise to be more visible in the samples for comparison. It was getting tougher to determine visually how samples were comparing. With this problem in mind I also added some statistical data to show the RGB noise characteristics and the mean, median and standard deviation are now shown.

New models added include bodies from Fuji, Nikon, Sony, and Pentax, including the new K1, along with the Fuji XPro2. I’m also hoping to add new search features soon to allow searching by sensor size. This will make it easer to compare common models.

I’d also like to thank Michael Zhang at PetaPixel for the great review of the Sensor Database on their site. Thanks for the write up, I’ve had a lot of positive feedback, and it certainly seems to have caused a lively debate.


70D and D7100 Sensor tests.

How well do crop sensor cameras work for long exposure work? I’ve just finished testing the 70D and D7100, you can review the results on the sensor test page. In regards to the Canon 7D mark 2, once Adobe supports the 7D mark 2 with the Camera RAW software I will be able to follow the same workflow and upload a comparison. So stay tuned, I expect it will perform better than the 70D.


High Mega Pixels, do I need it?

There always has been two schools of thought on just how many mega pixels (MP) you need in a camera. This issue seems to divide the photographic community to no end. In the first camp we have those that are of the opinion ‘I would be happy with just 4-8MP if it was sharp and clear with no noise’, while in the second we have the ‘More MP is better’.

I think both parties are correct, in fact the latter party once they have their high MP camera will use noise and clarity as criteria 2 for deciding on their purchase, or they will be willing to trade off a few MP to get lower noise.

Why do I think both parties are correct?, well it all depends on what you are going to use the photos for. If your printing 8×10’s or using them on a digital picture frame you don’t need anything above 8MP, in fact 2MP is enough for 5×7 or digital frame. 8MP will go to A3 or even A2 size with no problems, there may not be as much detail at that size and the details may be as low as 100 dots per inch (DPI), but at A2 most people don’t examine a picture closely, you must step back to appreciate it. In my opinion 10MP at A1 is acceptable for most subject matter. Most wedding photographers for example have 99% of there prints done at 8×10 or less, so 8-10MP is more than enough.

Why should I get a high MP camera then? Well it all depends on your subject matter. I mainly shoot landscapes, and I print them very large, A1, A0 or bigger. At these sizes with this subject matter people like to get up close and look at the finer details in pictures, ‘what is that? is it a shell?’. I have printed 21MP images up to 2m wide and at this size I would consider it the limit for my type of subject matter. Most serious landscape photographers printing at very large sizes are still using medium format or large format film and having them converted to digital, providing them with 40-80MP of data for medium format, and more for large format. It is also fair to say that if shown a 10MP A1 image next to a 21MP A1 image you could tell which one is  of higher clarify. The question you must ask yourself is, will I be printing at A2+ sizes? and if that 1 in 1000 shot is going to be at that size, would I be happy with the clarity? How close will people be viewing the picture?

If your print was printed to billboard size you would not walk up and look at it from 1 foot away would you? most billboards pictures are as low as 10DPI.

Print size and viewing distance are the most important factors when considering how many MP you need.

Optimal Viewing Distance: Viewing Distance = 1.5 x Diagonal of the Print.

The DPI or pixels per inch (ppi) needed for a print with acceptable quality is determined by dividing 3438 by the viewing distance.

Megapixels Pixel
Size PPI
6 3008 x 2000 4″ x 6″ 313 501 Excellent
8″ x 12″ 156 251 Excellent
16″ x 24″ 80 125 Excellent
7 3072 x 2304 4″ x 6″ 313 512 Excellent
8″ x 12″ 156 256 Excellent
16″ x 24″ 80 128 Excellent
8 3264 x 2448 4″ x 6″ 313 544 Excellent
8″ x 12″ 156 272 Excellent
16″ x 24″ 80 136 Excellent
10 3888 x 2592 4″ x 6″ 313 648 Excellent
8″ x 12″ 156 324 Excellent
16″ x 24″ 80 162 Excellent

As you can see 10MP is more than enough to print to 16×24 at over twice the acceptable PPI for the normal viewing distance.

See this article for more information about print size and view distance.

There are other considerations to take into account when determining the best PPI, these include: Viewing conditions, Delivery Media (Paper, Canvas, Digital Frame), Subject Matter, Noise (grain) and Brightness. Once you have the required MP for your subject and media, the next most important factor is noise or ISO performance, and this like MP is determined by the camera, all of the other points listed above the photographer has some control over except MP and noise. You can’t add MP, or improve the noise the sensor will create (without changing your exposure or shooting style), and this is why the two groups in photography are more MP and/or better noise at higher ISO’s.

So in conclusion if your printing normal subject matter at normal sizes to be viewed at a normal distance an entry DSLR will be more than enough, especially considering you would be struggling to buy a new camera with less than 14MP. If your going to want to do larger prints where the viewing distance may by varied or closer than normal then get a larger MP camera, or consider a medium format camera.