EF lenses vs RF lenses- We explore the top 5 reasons why Canon’s RF system of lenses offers superior quality compared to EF lenses. How to choose which is best for you.

Thanks for the comment! To be honest, I haven’t actually tried any UV fluorescence photography (other than this test) yet. It’s definitely on my to-do list, I’ve just been busy with other things.

Aperture also controls depth of field, which is used to separate your subject from the background. A small F-number, such as f/1.8, will give you a sharp focal point with a soft blurry background. A larger F-number like f/16 will give you a larger depth of field, resulting in both the foreground and background being in focus.

The EF-S lens mount is indicated with a white square on the lens and matched with the white square on the camera body. These lenses can be used on Canon DSLRs with APS-C sensors, such as the EOS 200D, EOS 80D and EOS 7D Mark II.

The aperture of your lens is the opening that allows light to enter and reach your camera’s sensor. It can be adjusted much like the irises of the human eye, which dilate or contract depending on the available light. In photography, the aperture of a lens is measured in F-numbers or F-stops and is typically expressed on your lens like the following: F/4.5-5.5. In this example, the minimum aperture for that lens ranges between f/4.5 and f/5.5, depending on what focal length you’re using. In general, the smaller the F-stop, the larger the aperture opening, and vice versa.

Camera lenses come in all shapes and sizes and are designed for different shooting scenarios. Check out the full range of Canon’s lenses here.

Zoom lenses, such as the EF-S 18-55mm f/3.5-5.6 III or EF 24-70mm f/2.8 L IS USM, offer a variety of different focal lengths. This makes them extremely versatile, which is why many photographers consider them to be essential – especially for travelling photographers who don’t want to carry multiple lenses.

Ultrafire torch w/ 330WB70 filter shiny side facing out - 0.4s. As you can see, it doesn't seem to matter which way round the filter is mounted on the torch.

So that led me to look at UV torches. The torches most recommended for UV / UV induced fluorescence photography use UV LEDs produced by the Japanese company Nichia. However, these are very expensive. There are much cheaper alternatives available, but are they any good?

Thanks for the pointer, though I already knew about that one – I’ve actually reviewed it here: More UV flash and torch tests. Of course, that flashlight wasn’t available at the time I wrote this post. You’re right, it’s a great value UV light.

Learn about the different types of EF, EF-S, EF-M and RF lenses and find out which will work best for you and your camera.

Travel and photograph your way through the vivid colours of India with these essential tips from travel photographer, Melissa Findley.

In conclusion, I think we can say that the really cheap 'UV' torches are actually just violet torches that output a tiny amount of UV. The cheap but not quite as cheap Ultrafire torch does output UV light. However, I seriously doubt that its peak output is 365 nm. It looses a large amount of light when the 330WB70 filter is added, even though this filter passes around 70% of light at 365 nm.

Ultrafire torch w/ Baader U filter pink side facing out - 0.4s. I tested to see if the direction the Baader filter was used in had any effect as well. You can see the Baader filter passes quite a bit more visible violet light than the 330WB70 filter.

Whether you’re a photographer, filmmaker or hybrid shooter, understanding how your lens works is every bit as important as honing your camera skills. Here, Canon Photographer Jenn Cooper sheds light on what those numbers on the lens mean, covering everything from focal lengths and aperture values to the different types of lenses and when to use each one.

EF-M lenses are designed for Canon’s EOS M mirrorless cameras, such as the EOS M50. These are the smallest of Canon’s interchangeable lens range, making them ideal travel cameras.

Wide angle lenses, such as the EF 10-22mm f/3.5-4.5 USM or EF 16-35mm f/4 L IS USM, have smaller focal lengths and can capture a wider perspective. This makes them suitable for landscape photography, or any type of photography where you are shooting in tight spaces, like architecture/interior photography.

I hope they can develop UV LEDs that are both more powerful and affordable. The ultrafire UV torch I have is far less powerful than sunlight, and I find even bright sunlight combined with high ISO difficult for handheld reflected UV photography. The results can be quite interesting though.

Canon’s DSLR (Digital Single-Lens Reflex) and mirrorless cameras are designed to have interchangeable lenses. This allows you to use the same camera body with a variety of different lenses. For example, a DSLR camera gives you the flexibility to use an EF 50mm f/1.4 USM prime lens when shooting portraits or an EF 70-300mm f/4-5.6 IS II USM telephoto lens when shooting wildlife.

ISO controls your camera sensor’s sensitivity to light. A lower ISO, such as ISO 100 or 200, is used in bright daylight or when shooting well-lit indoor scenes. Higher ISO levels, such as ISO 3200 or 6400, allow your camera to operate in low light conditions. However, the trade off is that high ISO levels introduce digital noise to your images. Where possible, it’s always best to shoot with a low ISO to maintain the best image quality.

Ultrafire torch w/ 330WB70 filter black side facing out - 0.4s. The 330WB70 filter has a shiny red side and a dark black side. I decided to test with the filter in both directions in case it had any effect.

RF lenses feature Canon’s newest lens technology and have been designed specifically for the Canon EOS R and EOS RP full frame mirrorless cameras.

It’s important to know which lenses can be used with your camera. If the name of your lens starts with EF, EF-S, EF-M or RF, this indicates what type of lens mount your camera has. Each lens mount connects to their respective camera bodies.

EF lenses are Canon’s professional range of lenses. These are indicated with a red dot and commonly feature a red ring around the outside of the lens which is the signature for our L series lenses. These can be used on all Canon DSLRs, and on Canon’s mirrorless cameras when using an adapter.

One possible solution would be to use a UV-pass filter in front of a full spectrum flash. This would require making some kind of filter holder to hold the filter in front of the flash. I also didn't really want to have my expensive Baader U filter blasted at close range by hot flash.

Ultrafire torch w/ Baader U filter gold side facing out - 0.4s. As with the 330WB70 filter, it doesn't seem to make any difference which way round the filter is mounted.

Tags: UV induced fluorescence, UV Photography Posted in Reviews and info | 4 Comments » This post: Cheap UV torches / flashlights for UV induced fluorescence comparison Last updated 2016/08/15 by Dave Kennard You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

So, I purchased from ebay Optical Filter 330WB70 25mm Excite Fluorescence High Transmission 70%. This passes light from around 300 nm - 400 nm, cuts visible light, then starts transmitting some IR from around 810 nm. So by adding this to the torch, I can block any visible light it produces and turn it into a true UV torch.

Macro lenses allow you to zoom in and focus on subjects at extremely close distances. Macro lenses such as the EF-S 35mm f/1.8 Macro IS STM, enable the objects to look larger than life size with greater detail. This is ideal for magnifying insects, flowers or manmade objects and capturing them in extreme detail.

Lenses work similarly to the human eye and allow you to control the amount of light that enters your camera. Inside each lens is a series of convex and concave optical elements that work together to bend light and refract it into a single sharp focal point.

While I have done quite a bit of ultraviolet photography in the past, I haven't done any ultraviolet induced fluorescence photography. This involves lighting the subject with UV light, but recording an image that only includes visible light. The idea being to capture any visible fluorescence caused by the UV light.

The first thing I noticed when I received the torches was that all three gave out a lot of visible violet light. The ultrafire torch gave quite reasonable results when shone through my Baader U filter. The other two torches gave very faint results when shone through the Baader filter, but it did make the fluorescence easier to see than with no filter.

Every lens has a specific focal length, or magnification number, which is measured in millimeters (mm). This is normally displayed on the lens itself.

Cheap UV torch 2 (Aluminium UV Ultra Violet Blacklight 9 LED AAA Flashlight Torch Light Lamp) - 0.4s. Not much different from the other torch.

Before I go into my test, I should mention a couple of tests others have done, which test a different selection of UV torches: Extreme Macro: Lighting For UV Macro and BudgetLightForum.com - Review: UV light shootout, seven lights tested.

Lenses with larger focal lengths are called telephoto lenses and offer greater magnification when shooting subjects that are far away. For example the EF 100-400mm f/4.5-5.6 IS II USM lens is often used for wildlife and sports photography, allowing the photographer to zoom in on the animal or athlete when it is not possible to get close to them.

Selecting a small aperture like f/2.8 will let more light through the lens, which means you can shoot in low-light with a lower ISO and faster shutter speed. On the other hand, f/16 will limit the amount of light passing through the lens, meaning you will need to compensate by selecting a higher ISO or slower shutter speed to achieve the same exposure. The relationship between these three functions is commonly known as the Exposure Triangle Basics.

Lenses that have only one focal length, such as the EF 35mm f/2 IS USM or EF 50mm f/1.8 STM, and are known as prime lenses. Prime lenses don’t allow you to zoom in on your subject. However, because they have fewer lens elements, and fewer moving parts in general, they typically offer superior image quality.

Ultrafire torch - 1/80s. We can just see the fluorescence of the security marking, but it is swamped by violet visible light produced by the torch.

The longer the focal length, the higher the magnification. The shorter the focal length, the lower the magnification. For example, a lens with a focal length of 24mm will offer less magnification than a lens with a focal length of 200mm.

The first two are both 9 LED and take 3 AA batteries. Both cost about 99p and strangely both had one LED not working (so they were actually 8 LED). The Ultrafire torch was probably a bit over £20 when you include the cost of the special batteries and charger it requires.

The difficulty in doing this is finding a light source that emits only ultraviolet light. If we have a source that emits UV and visible light, then the visible light output will likely overpower any fluorescence in our image. So that means a full spectrum flash is not suitable.

Good article, I had very similar results when I was tottering about testing these. It’s a shame you’re not closer to Surrey, I’d be very happy to lend you my MTE U301 for a play – this was about the cleanest non-spill source I could find. This LED technology is developing quickly though and I don’t think it’ll be too long before there are decent 365nm lightsources available with the brightness to take handheld shots UV. You can get close already with high ISO but another order of magnitude wouldn’t hurt.

Cheap UV torch 1 (Waterproof Outdoor 380-400nM UV Ultra Violet LED Flashlight Light Torch Lamp) - 1/5s. Seems like a lot of violet light but not much UV.

Prime lenses also have low aperture values, such as f/1.8 or even f/1.2, which means they offer a shallow depth of field. This makes them suitable for portraits and product photography, or any type of photography where a soft blurry background is desired. These wide apertures also allow more light into your camera, making them ideal for shooting in low light conditions.

The test subject was the UV security feature on a Bank of England £10 note. This has a number 10 that cannot be seen under normal light, but fluoresces under ultraviolet light. According to the Bank of England A UV lamp that emits light at around 365 nanometres is ideal for checking the fluorescent features.

I kept the aperture and ISO the same for each shot, but varied the shutter speed. I'll include the shutter speed below each image.

Including postage, tax, and post office fees the filter came to around £40. So it puts the price of a cheap UV torch up considerably. But it still keeps the price a lot less than the torches using Nichia UV LEDs.

I'd really like to try out the MTE U301 torch, which uses a Nichia UV LED, and see how that compares. However, at around £120 it's a bit much for me. Maybe if I get into UV fluorescence photography a bit more, then I'll consider it.