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Tag: Low

Sony A7 III sensor testing.

Brendan

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.


Sensor DB Upgrade.

Brendan

It has been a while since the Sensor Database has been upgraded, and it was time with the recent additions of some never sensors.

New features include a better layout with less clutter for comparing models. I have also added pop-up images to allow users to see a true 1:1 view of the sensor noise, rather than a 50% browser rescale. These new features will allow for better comparisons as sensors continue to improve.

To view the new Sensor DB, click here

Canon Consistent with EOS-R & RP

Brendan

Canon have improved the sensors in the EOS R and RP. The R sensor is based on the same sensor we see in the 5D mark 4, and the RP is based on the same sensor in the 6Dm2 and Canon have managed to squeeze a little more out of both for some good results.

EOS-RP v’s 6D mark II

As you can see the EOS-RP sensor performs much better than the 6Dm2 sensor over the whole range of long exposure times. Canon have possibly continued to improve the manufacturing process or the new DIGIC processing is really working some extra magic. The RP is where I expected the 6Dm2 sensor to be after the fantastic long exposure performance of the original mark I. Better late then never.

EOS-R v’s 5D Mark IV

The EOS-R is also better than the 5D mark IV. It’s not the same jump in sensor improvement as the RP, but it’s still a big improvement of almost 20% less noise at 1 second. Again there is consistent gains over the long exposure testing range.

So it’s a good gain for Canon, but I do feel disappointed again, just like I did when testing the 6D mark II. Canon are making consistent gains with each new model, but the long exposure sensor noise is where the competition was years ago.

Mirrorless, Nikon and Canon

When comparing the R and RP to the Z6 and Z7 based on long exposure base noise alone It would be difficult to recommend Canon, especially if you are not gear biased. The R/RP may do better for extreme long exposures of 5 mins or more, but how these models would compare with dark frames added to remove noise for extreme long exposure I don’t know.

Conclusion:
If you are currently using Canon then the R and RP are a good step up from the 5D mark 4 and 6D mark 2 in regards to sensor noise. If your thinking of upgrading to mirrorless I think both these would perform well and give good results. It’s possibly the most sensible path to go down if you have a lot of EF glass and just want to expand your kit.

The EOS-R has the best long exposure low noise sensor from Canon over 20MP, so if you are after Canon, this is the one to buy. The EOS-RP is also very respectable and not far behind. Will they be the cleanest images money can buy for long exposure?, No I expect not.

If you would like to compare the EOS-R and EOS-RP to more models, or learn more about the sensor database click here.

Again, a big thanks for Alex @Stallards in Hobart for access to these cameras for testing.

Fuji X-T3. Third time lucky?

Brendan

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?

Conclusion:
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.

Nikon D7500 Long Exposure Monster.

Brendan

I’m impressed, the Nikon D7500 is the best crop body I have tested so far for long exposure. It out performs all previous models by quite a margin, taking even the title form the D500. At 1 second it out performs the new Canon 6D Mark II which is full frame, and is is only slightly worse at 30 seconds. Check out the results and compare models here.

 

Night Focus, Easy As….

Brendan

Okay so we have all sat in the picture theater and thought “Focus FOCUS”, and maybe recently you started to shoot at night only to find your camera was not up to the task.

“Yer, my camera won’t focus, so how do you focus to infinity at night?”

Most cameras are not designed to focus in extreme low light, and will require manual intervention, switch the lens from Auto to Manual focus mode.

“Ok, so my lens is now in manual mode and I set the focus to infinity but it’s still blurry?”

This is normally the case as the infinity mark is almost never perfect, think of it like the pirate code, that is more a “guide”.

“You mean I can’t focus at all at night?”

There are a number of ways to get perfect focus in the dark, here are the 2 easiest.

1. If your camera supports live view use it. Set you lens to manual focus, and focus to infinity, then using live view and zoom (normally 10x) you should be able to locate a distant light on the horizon or bright star you can adjust the focus on to get it perfect. This will require some practice and stars or faint objects may only work on better / later model cameras and lens with larger apertures like f2.8 and lower.

2. If your camera does not have live view then during the DAY have your camera focus on a distant object in auto focus mode (something on the horizon), then looking at your lens note where the focus mark is, it should be near infinity, but it probably wont be exactly on it. Take note of the location, or place some masking tape next to the mark and mark it with pen so you can manually move the focus back to this spot later. Repeat this a few times to confirm the mark. Now at night set your lens to manual focus and move the focus to your recorded mark. This method is not as good as the one above as lenses have a little bit of “play” or tolerance, but it should be more than good enough for infinity focus.

There you have it two ways to get perfect focus in the dark. – Cheers.

Aurora Australis

Brendan

Aurora AustraliaMy experience with the Aurora.

I have shot a few Auroras now, most at fairly low light levels when compared to those at very high or low latitudes. I have shot a nunber at around 42 degrees south from Tasmania, and here are my tips for shooting Auroras that are just visible to the eye.

Light, it’s all about light. The fastest glass is going to give you the best results, why? Auroras are funny things, large light curtains that slowly move and weave across the night sky, in order to get the best picture you need to “stop” or have as little movement in the curtains as possible. There are only two ways to do this while keeping your exposure short, either you increase your ISO or you open you lens f-stop to allow more light in. Increasing the ISO is not ideal as it adds more noise, and only the best cameras will have usable low light pictures at high ISO’s

The picture above was shot at ISO 800 for 2 mins at f4 with a 17-40mm, in this example you can just start to see start trails, and the aurora is flat with little variation across the color bands. f4 on this lens was the max f-stop for light. If however I had used a 24mm f1.4 I would have been able to reduce the time period by 3 stop or an exposure of 15 seconds @ f1.4 at ISO 800. This would have given the same overall exposure but allowed for more variation and exposed the ribbons better.

So, get the fastest glass you can afford, and this is sometimes a trade off with focus length. For example 16-35mm f2.8 v’s 24mm f1.4, the 24mm is going to allow a lot more light in, but will not be as wide as the 16-35, and the cheaper 17-40mm f4 is going to allow even less in. Another option is the Sigma 20mm f1.8 if you can handle it’s softness.

What else do I need to know? Well, don’t try shooting an aurora near other light sources, such as cities. If you moon is up, and all but a slither then forgot it, it’s going to wash your aurora shots out. Use a good tripod, I can’t stress it enough, don’t buy a cheap flexible tripod for low light photography. the slightest movement is going to wreck your shot. You can used ND grads, and they will help to even out brightness. Know where infinity is on your lens, as you may not be able to see enough to focus. Some cameras show stars in live-view zoomed in and you can focus on them, or a light source far in the distance.

Night Photography, Nikon v’s Canon

Brendan

Fort Direction Sunset

I have been a user of the 5D mark II since the day it was released, well almost. It’s a great work horse, delivering consistent images regardless of the situation. Then along comes the Nikon with the D800, and it’s smaller brother the D600. Are they any good for landscapes compared to the Canon? After some very extensive research on the web (hours of reading articles), I decided to move to Nikon, with the D800 being all the rage. So I borrowed a friends D800, and a D300s to do some basics comparisons and to get used to the Nikon bodies. What I will discuss here is how Nikon compares to Canon for low light landscape photography. The types of light levels I’m discussing are around 30sec / f2.8 / 1600ISO.

The D300s I was considering for a second body, as is of the same era as the 5D mark II. It was useful to confirm the D800’s metering as discussed below.

Live View

Canon has always had a good live view system, particularly with the frames per second delivered to the LCD on the rear of the camera. The first thing I noticed with Nikon was increased noise and significantly reduced frame rate when viewing zoomed in content on the Nikon, particularly in low light. The combination of these two factors made it very difficult to focus the camera, and I stress ‘very’, with the Canon I could focus on a star for example, while with the Nikon the frame rate was so low it was very difficult to focus, not impossible, just frustrating. I did however like the inbuilt level feature. Insuring the horizon is level at low light can be difficult.

Exposure

I’m sorry, but the Nikon is next to useless for getting the exposure anywhere near correct at extremely low light. In very low light conditions the Nikon did not meter anywhere near correct, and was metering at least 3.5 f-stops below the Canon. Having said that the Canon was also metering low as well and I was clearly in the manual settings / try and see space. It could be that Nikon allows significantly more light in through the view finder? It was nice to see that the D800 did have a shutter for the viewfinder, which was a welcome relief from the rubber boot / strap cover. To be fair on the Nikon the conditions were well outside of normal photography, and even the Canon was struggling, but closer to the mark.

Color Balance

The Canon always delivers good color balance, and very rarely do I have to set it to daylight or any other setting, even when shooting at night. The Nikon however was struggling and needed to little more help to get the balance correct, most of the pictures were turning out a very dark blue. Having said that, this is not a major issue as I always shoot RAW, and this can easily be corrected in post. Most likely the slight color balance issues were getting worse at lower light: “The D800 was noticeably sharper, while the Mark III produced more accurate colors, with a superior white balance system.” – http://www.digitalcamerainfo.com/Features/Head-to-Head-Nikon-D800-vs-Canon-5D-Mark-III.htm

Long exposure artifacts

When taking very long photos the D800 was introducing a lot of random white spots into photos, I would not consider them to be “hot” pixels, but they were quite strange. a quick Google search later and I discover it’s a nice feature: http://scottreither.com/blogwp/2012/07/01/nikon-d800-e-long-exposure-issues-problems-2/ & http://www.flickr.com/groups/1567431@N22/discuss/72157632780538698/ are two such examples.

 

Conclusion:

I think this video shows most of the points above: http://vimeo.com/42381520. You can clearly see the under exposure, incorrect color balance, and some noise being introduced, even at 1/50. Extend that to a 5 min exposure and it all goes pear shaped.

There is no doubt that during the day or in moderately low light the D800 will perform as well a a 5DmX, if not better. However at extreme low light I do not believe the D800 is the best choice. It’s clear, at least to me, that this is pushing the camera to it’s limits. So for the time being I will hold onto my 5DmII, and hope that Canon will introduce some of the new options in their next 5D body, along with maybe a few more Mega Pixels.

 

Also, D300s Frames Per Second?

This is completely not related, but a surprise to be sure. We all like to get the best out of our gear, so I always set my camera to 14-bit RAW were possible. With the D300s I noticed something interesting, the factory setting is only 12-bit RAW, thus allowing up to 7.5fps dependent on other settings. However increasing the quality to 14-bit RAW reduced the fps to 2.5 max (ouch). I rarely shoot more than one frame at a time and could not care less. However  I wondered if this was just a marketing “trick” from Nikon’s to make the camera look better than it really is? How fast would a Canon body be at 12-bit RAW?