Why sensor dust is more visible at small apertures

Dust on Sensor

Another reader of ours, Frank Di Luzio, sent the below image that explains exactly why sensor dust is more visible at small apertures. While I have explained this phenomenon to some of our readers before (see the comment section), I have not had a chance to write a separate article with a proper illustration, demonstrating how aperture size affects the shape and size of dust particles. Thanks to our generous readers like Frank, I now do not have to do it, because the below illustration is perfect.

Dust on Sensor

In summary, when the size of aperture is large (a small F-number like f/2.8), light rays reach dust particles that are sitting on the sensor filter from different angles. Remember, although I refer to this as “sensor dust”, dust actually never touches the sensor, because there is a thick filter (actually, more like a number of filters packed together to form a single filter) that sits in front of the camera sensor. Therefore, by the time light reaches the physical sensor, it is spread out on a very large area, making dust appear as a large blob with a soft ring. When using very large apertures like f/1.4 on fast prime lenses, these blobs might be so washed out that they might be practically invisible to your eye. That’s why portrait photographers notice dust less often than landscape photographers!

Now when the lens is stopped down and aperture is significantly smaller, say at f/16, light rays coming from the lens diaphragm are perpendicular to the sensor filter. Because the angle is more or less straight, dust specks also cast direct and defined shadows on the sensor. That’s why dust shows up in images much smaller, darker and with more defined edges at small apertures.

Big thanks to Frank for sending the illustration!

Benefits of a High Resolution Sensor

Nikon D4 Sensor

As camera manufacturers are continuing the megapixel race, with Sony releasing a bunch of 24 MP APS-C (1.5 crop-factor) cameras like Sony A77, A65 and NEX-7, and Nikon releasing a high resolution 36 MP Nikon D800, many of us photographers question the need for such a high resolution sensor. Some of us are happy while others are angry about these latest trends. Just when we thought companies like Nikon abandoned the megapixel race, instead of seeing other companies do the same, we now see Nikon back in the game with a new breed of product with a boatload of pixels. Why did Nikon all of a sudden decide to flip the game? Why does everyone seem to be going for more pixels rather than better low-light / high ISO performance? Does a high resolution sensor make sense? What are the true benefits of a high resolution sensor? In this article, I will provide my thoughts on what I think has happened with Nikon’s camera strategy, along with a few points on benefits of a high resolution sensor.

Nikon D4 Sensor

Pixel Size, Pixel Density, Sensor Size and Image Processing Pipeline

OK, this topic is rather complex if you do not know anything about pixels and sensors. Before you read any further, I highly recommend to read my “FX vs DX” article, where I specifically talk about pixel and sensor sizes and their impact on image quality.

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Nikon D4 vs D800

Nikon D4 vs D800

While the Nikon D800 has not officially been released yet, its specifications have been leaked for a while now, so our readers have been asking more and more questions about it. In this Nikon D4 vs D800 comparison, I will write about the rumored specifications of the D800 and compare it to the Nikon D4. While these cameras are for completely different needs and obviously are at difference price points, both are generating lots of interest from the Nikon community. Once the Nikon D800 is officially released and I have both cameras, I will provide much more detailed analysis of differences between these cameras, along with image samples and ISO comparisons. Please keep in mind that some of the D800 specifications below are pure speculation and might not match the actual specifications of the camera when it is released.

Nikon D4 vs D800

Before I get into the camera specifications comparison, let me first talk about these two cameras. The Nikon D4 is a high-end DSLR targeted at news, sports, wildlife and action photographers. It is Nikon’s new flagship low-light king with very impressive high ISO capabilities and extremely fast speed, both in terms of autofocus and camera frame rate. To allow for such impressive low-light performance, Nikon had to keep the pixel size large, which translates to lower resolution (by lower I mean 16.2 MP). The upcoming Nikon D800, on the other hand, is aimed at landscape, architecture and fashion photographers that need high resolution for large prints.

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Nikon D4 vs D3s

Nikon D4 vs D3s

Many of the current Nikon D3s owners like me probably wonder about the differences between the new Nikon D4 and the now obsolete Nikon D3s DSLR cameras. While I do not yet have the Nikon D4 to do more in-depth side by side comparisons, I decided to write about differences in body design and specifications between the two. More details about the Nikon D4 will be published in my upcoming Nikon D4 review.

Nikon D4 vs D3s

First, let’s talk about differences in camera body design.

Nikon D4 vs D3s Camera Body Design Comparison

As expected, the Nikon D4 went through rather significant changes in camera body design. The overall shape of the camera has been completely changed and it now looks more curved than the D3/D3s/D3x models. Let’s start from the front of the camera, which went through the least number of changes. The only major change I see on the front is the C/S/M focus lever (bottom left side of the camera) that has been modified to adapt to the same switch we see on the Nikon D7000 DSLR. This was a good design change, because it will prevent accidental changes to autofocus when you pull the camera out of the bag. Now the switch only has two options – AF for autofocus and M for manual focus. The button on top of the switch replaces the AF mode switch on the back of the camera. Now you can switch between the different AF modes (single, dynamic and 3D) by pressing this button and rotating the camera dial. Oh and it looks like the grip is shaped a little differently, which should help with handling the camera a little more.

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Nikon D4 DSLR Announcement

Nikon D4

Nikon has just released the much anticipated Nikon D4 DSLR, a major update to the existing Nikon D3s camera that was released back in 2009. The Nikon D4 is Nikon’s flagship DSLR, designed specifically for sports, news, wildlife and event photography that require superb low-light capabilities. Due to the high resolution sensor of the Nikon D800, we might not see a Nikon D4x for landscape and fashion photography needs, but a Nikon D4s might follow in a couple of years.

Nikon D4

So, what does the Nikon D4 bring to the table? Here is a summary of its features:

  1. Sensor: 16.2 MP FX, 7.3ยต pixel size
  2. Native ISO Sensitivity: 100-12,800
  3. Boost Low ISO Sensitivity: 50
  4. Boost High ISO Sensitivity: 25,600-204,800
  5. Camera Buffer: Up to 100 12-bit RAW images, 70 14-bit uncompressed RAW and up to 200 JPEG images in continuous 10 FPS mode with XQD card
  6. Processor: EXPEED 3
  7. Dust Reduction: Yes
  8. Shutter: Up to 1/8000 and 30 sec exposure, self-diagnostic shutter monitor
  9. Shutter Durability: 400,000 cycles
  10. Camera Lag: 0.012 seconds
  11. Storage: 1x Compact Flash slot and 1x XQD slot
  12. Viewfinder Coverage: 100%
  13. Speed: 10 FPS, 11 FPS with AE/AF locked
  14. Exposure Meter: 91,000 pixel RGB sensor
  15. Autofocus System: Advanced Multi-CAM 3500FX with 51 focus points and 15 cross-type sensors
  16. AF Detection: Up to f/8 with 11 focus points (5 in the center, 3 on the left and right)
  17. LCD Screen: 3.2 inch diagonal with 921,000 dots
  18. Movie Modes: Full 1080p HD @ 30 fps max
  19. Movie Exposure Control: Full
  20. Movie Recording Limit: 30 minutes @ 30p, 20 minutes @ 24p
  21. Movie Output: MOV, Compressed and Uncompressed
  22. Two Live View Modes: One for photography and one for videography
  23. Camera Editing: Lots of in-camera editing options with HDR capabilities
  24. Wired LAN: Built-in Gigabit RJ-45 LAN port
  25. WiFi: Not built-in, requires WT-5a and older wireless transmitters
  26. GPS: Not built-in, requires GP-1 GPS unit
  27. Battery Type: EN-EL18
  28. Battery Life: 2,600 shots
  29. Weight: 1,180g

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Nikon D3s Review

Nikon D3s

Just a few days before Nikon D4 is announced at CES, I decided to write a review of the Nikon D3s DSLR that I have been shooting with for the past two plus years. I have been putting off writing the review for a while now, because I wanted to first review all the gear that I have been testing lately, while the gear I use every day for my photography has been just sitting at the end of my long “to-do” list. The Nikon D3s has received numerous awards, including “best product / camera” from various reputable organizations and websites. And it did for a reason – its image quality, high ISO performance, superb autofocus, fast speed and rich features make it a phenomenal camera – truly one of the best cameras in the world.

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Nikon D700 Review

Nikon D700

While the photography community is impatiently waiting for a Nikon D700 replacement announcement, I decided to write a review of the Nikon D700 DSLR that I have been shooting with for the past three years. Not sure why it took me so long to write a review of my favorite camera…I guess I focused so much on reviewing new lenses and cameras, that the gear I use every day for my photography has been just sitting at the end of my long “to-do” list. Within the next few weeks I am planning to temporarily reverse the list, start from the bottom and write about other gear that I currently use and used in the past and share my subjective opinion about it.

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Nikon Quality Control Issues

Nikon D700 Rubber Issue

Like any manufactured product, Nikon’s products are also prone to quality assurance / quality control issues. While Nikon has a very extensive and comprehensive quality control process, some defective products can slip through and make it to the market. Other times, the pressure to increase the production output on Nikon’s manufacturing plants is so high, that the initial shipments of a newly introduced product can be defective or could have other problems not discovered during the initial testing of the product. Unless the defect is of physical nature, the latter is typically addressed through firmware updates later, which Nikon is pretty good about.

Nikon D700 Rubber Issue

Nikon D700 Rubber Issue

In this article, I would like to point out some of the recent quality control issues I have seen in Nikon products. Specifically, on the latest generation DSLRs like Nikon D700/D5100 and some of the newer lenses, like the Nikon 24-70mm f/2.8G. Why am I doing this? Because first, I want to make our readers aware of potential QA (Quality Assurance) issues they might encounter and second, I want to provide some information on how to react to such problems. Please bear in mind that the purpose of this article is not to scare existing or potential Nikon customers. In fact, every manufacturer, including Canon and Sony occasionally have issues with defective parts and products, so this article could apply to other brands as well.

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Nikon D5100 Review

Nikon D5100

This is an in-depth review of the Nikon D5100 DSLR, based on my two month experience with the camera. Marketed as an upper-entry-level DSLR, the Nikon D5100 is a major upgrade to the older Nikon D5000. It has a larger and a more enhanced swivel LCD screen and the same remarkable sensor as the semi-professional Nikon D7000. In addition to the above changes, the Nikon D5100 also lost some weight, making it lighter and more compact than the Nikon D5000. In this review, I will provide a detailed analysis of the Nikon D5100 and compare it against the Nikon D3100, D5000, D90 and the current Nikon D7000 DSLRs.

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AjRichard – Beware of buying gear from unauthorized sellers

AjRichard Order

I recently witnessed how a friend of mine got robbed by an online camera store called AjRichard based out of New York, USA when he purchased a Canon 5D Mark II. The camera was out of stock for a few weeks in every single local and online store he trusted and he could not wait any longer. That’s when he decided to expand his search and see if he could find an Internet store that had the 5D MKII in stock. He eventually ended up on Nextag.com looking at a list of merchants with “in stock” indicators. The top sellers all had very high ratings and he noticed that some of the sellers were advertising the 5D MKII at lower than the $2,500 “normal” rate that everybody else sells for. The top result was AjRichard.com and with over 1,000 reviews, 5 star rating and a “Trusted Seller” status, he decided to take the plunge and order the camera at just $2,350 – a really good deal he thought he was getting. The sad part is, he felt something was not right while making the purchase and still did it, thinking that his credit card company would protect him in case something went wrong. Next day, he got a call from AjRichard sales rep, who told him that camera battery and charger were not included in the $2,350 price and convinced him to buy those, along with some accessories he did not need. The order went up to $2,629 and he was promised free three day shipping. He needed the camera ASAP, so he agreed to complete the transaction and paid in full. Here is what his order looked like:

AjRichard Order

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