Neutral density filter (ND) naming and optical density

If you are thinking to invest in a decent filter system to include in your photography gear, I am sure the nomenclature might have baffled you a bit. I got lucky to be able to borrow a few grad filters from my friend who is a professional wedding photographer. This allowed me to fiddle around a bit with different level of optical density and thus served as the photography inspiration behind this post. The naming of the neutral density filters ( either gradual or non gradual) is like a photography myth, but this short and sweet post will make it easy for you. Some filter manufacturers name them as per optical density of filter while others focus on f-stop number.
Table below relates optical density, filter factor and f stop number for neutral density filters.

Optical density of filter:
0.3     0.6     0.9     1.2     1.5     1.8     2.1      2.4     2.7     3.0  
Filter factor:
2         4        8        16      32     64     128     256    512    1024
F stop:
1         2        3         4        5       6        7         8         9      10

Example: 0.9 ND filter. This means it is a 3 f stop ND filter. Similarly, a 10 f stop ND filter would have an optical density of 3.0. 

So we have got the basic of density filters, but what's the main motive behind spending money on density filters. There are certain aspects of photography which require a use of ND filter. As an example: 

1) Outdoor portrait photography: Neutral density filters help for outdoor portraits in broad daylight. Example: Sun is behind your model or subject. In this case a balance between ambient light and subject exposure can be achieved by using a fill flash and ND filter. Fill flash will prevent shadows on subject face and pop out the subject more. Other way can be exposing for the background which would require a very high shutter speed and great flash power. For detailed explanation, see the last post on High Speed Sync.

2) Landscape photography. Shooting in harsh daylight sun can be made possible by using ND filters of higher optical density. Capturing sunset over the beach using ND filter gives a nice and silky effect to waves and leads to properly exposed sky. ND filter actually allows a longer exposure as it minimizes the amount of incoming light. 

Pro Tip: If you find it hard to focus after attaching filter, focus before on a point (either manually or auto) and then switch your lens to manual mode. Slide the filter in front of your lens and boom. There is a huge debate of using screw on density filters vs square shaped filters which require a holder system such as Lee SW150. 

Be a DSLR Ninja. 





How to decide between TTL and manual mode for external flash photography?

My recent love for doing dslr photography using external flash has made me do a lot of experiments in past 2 weeks. In the previous post we talked about how does HSS and TTL mode impacts the output of dslr flash and ultimately the image exposure when doing photography. This post will summarize what mode of operation to prefer when doing photography based on your subject, lighting, etc. 
The mode of operation of an external flash in photography is classifies into two main types:
1) TTL 
2) Manual
TTL: Through the lens. Canon dslr models have E-TTL whereas Nikon ones have i-TTL for the same mode.
When to use: Indoor photography with rapidly changing lights, fast movement, changing angles, distance variation from subject,etc. are some major factors where ettl comes to rescue. It is not convenient to adjust the flash power every time in order to take a shot just because lighting changed. What would happen? The shot that you wanted to take might be gone by the time power is adjusted. If you are going to change aperture or shutter speed as well, try to stick with TTL. I usually like to keep TTL flash on my camera hot-shoe. 
Bad side: TTL uses 2 flashes, one for metering and other one for actual shot. This makes it really heavy on power consumption. Be sure to carry an extra pack of batteries. 

Manual: Like the word itself says, this mode involves setting the power manually. 
When to use: Outdoor portraits, studio portraits, off camera flash. This mode of external flash operation works really well when a user has full control over the subject and lighting. Example: Portrait photography. 
Bad: For me, the only inconvenient thing was multiple physical movements required to adjust power. 

Pro tip: 
1) Variation of f-stop in dslr photography controls flash exposure, whereas shutter speed controls ambient light.
2) The manual changing of flash power and zoom level can be done by using optical or radio based triggering. 

Be a DSLR Ninja. 



How does E-TTL and HSS impact exposure in a dslr camera?

I bought my first dslr camera external flash (Yongnuo 568 EXII) long time ago, but didn't even touch it as I mostly do landscape and city architecture photography. Adding a small amount of light on your subject during night photography makes it look more interesting, but I wanted to try something different. Example: Outdoor portrait photography.

I am writing this post about my recent experience trying outdoor portraits with a dslr for the first time. One of my close friend agreed for being the test subject for daylight portrait photography. I watched a lot of videos about High speed sync, TTL mode and outdoor portrait photography posing techniques, but was still nervous about the friendly photography shoot.

My flash, lens, camera were working fine on the day of shoot, it was me who wasn't able to judge the harsh late afternoon lightning which definitely led to embarrassment. Shooting RAW format definitely helped, but I still wasn't satisfied with the results. I wanted to practice more and see how my on camera external flash behaves on using HSS( High Speed Sync) and E-TTL mode. As a total beginner with external flash based photography, I learned quite a few really important things in past couple of days.

High Speed Sync: Allows you to exceed shutter speed when an external flash is connected to your camera. The default max value is 1/200 or 1/250 in most canon cameras. You can check this maximum by connecting an external flash physically to your camera and rotating the shutter speed dial.Why high speed sync? Well,  high speed sync is an extremely important feature for outdoor portrait photography. When taking a portrait against brightly lit and distracting background, it is good to have a shallow depth of field. This means the f stop value should be on the lower side like 1.2, 1.4, 1.8, 2.0, 2.8, etc. This opens up the aperture and more light starts to reach sensor when a picture is taken. In order to balance the amount of light, high shutter speed is required otherwise the background would appear to be blown out. The role of external flash is to illuminate your subject and maintain a proper exposure during photo shoots.

E-TTL vs Manual Flash: Let's talk about canon cameras. E-TTL (Through the lens) is like an automatic adjustment of flash power as soon as shutter is pressed. If the aperture or shutter speed value is varied, the flash power is adjusted in order to keep the subject properly exposed. The required power level is determined with a pre flash. There is a pre-flash but it won't be visible easily. Change your external flash settings to second curtain and lower shutter speed like 1 or 2 seconds. You will see two different light flash now. The first one determines the exposure and second one is the primary light hitting the sensor.
Here are a few sample pics:
1) E-TTL
F5.6, Same focal point. ISO 100

dslr photogtraphy in E-TTL mode
E-TTL mode: 1/10 Shutter speed
dslr photograph in ettl mode
E-TTL mode: 1/100 Shutter speed



dslr photograph in e-ttl mode
E-TTL mode: 1/250 Shutter speed

dslr photograph in e-ttl mode
E-TTL mode: 1/800 Shutter speed
TTL means through the lens. The pre flash reflected from subject goes through the lens and determines the final power output. In order to take the last photograph, high speed sync on Yongnuo 568EXII was involved as the max sync speed on my Canon 40D is 1/250 seconds. From above 4 example images, it is really clear that flash output is trying to maintain constant exposure of the subject.

2) Manual
Same  F5.6, focal point and ISO.

dslr photograph in manual mode
Manual mode flash: 1/100 second
dslr photograph in manual flash mode
Manual mode flash: 1/250 second


dslr photograph in manual flash mode
Manual mode flash: 1/500 second

dslr photograph in manual flash mode
Manual mode flash: 1/1600 second
Manual mode means the photographer or user takes control of the power. In other words, manually adjusting power level every time more or less light is needed. Let's set the flash to a full power level i.e. 1/1. Other options are 1/4/. 1/16. 1/32, 1/64, 1/128.In order to take the last two images, had to turn on the high speed sync on 568EXII. It is easily noticeable that the exposure of subject varies with shutter speed. Every time a picture is taken, same intensity level flash is fired.

Summarizing, outdoor portraits need high speed sync when using a fill flash and higher intensity of flash power as well. Exposure starts to go down because of less light availability as explained in the previous post about impact of shutter speed on light. Distance between subject and photographer or dslr camera also matters when doing high speed sync portrait photography.
These two points were lacking in my first outdoor portrait photography shoot, but I will do it again soon with a better level of experience gained from my mistake.

Be a DSLR Ninja.

Good and bad things about Canon's entry level photography camera T5 (1200D).

One of my friend bought Canon T5 (1200D) as his first camera for getting into photography. He wanted me to have a general look over it, and I think there is no better topic for another blog post.
Here is my view about Canon's entry level T5 (1200D) photography camera:

Good things:
1) High megapixels: T3 only has 12.2 megapixels, so a decent upgrade to 18 megapixels here. This allows better cropping without losing clarity or details. Also bigger sized prints which can be really helpful for landscape photography or fine art prints.
2) Light weight: Only 480G. Easy to carry on hiking and outdoor visits. Oh, and the neck won't hurt while doing photography using this camera.
3) Full HD video recording: This is a big upgrade over T3 which only supported 1280*720.
4) Increased ISO range: Maximum of 12800 replacing 6400 limit of T3.


Bad things:
1) No dedicated DOF button: C'mon Canon. Either make the settings option browsing simpler or provide a dedicated depth of field button. I tried reverse lens macro photography with my friend's camera and it was a pain to lock the aperture blades as there was no dedicated button to lock it.

4) No continuous auto focus during video: T5 has full HD recording (1920*1080) which is a great feature, but it can be disappinting to see blurred subjects just because your camera doesn't know how to auto focus while recording a video. Yes, refocus is allowed while recording is in progress but it doesn't offer a smooth transition and takes a lot of time due to slow AF. This was one of the major setbacks for T5 (1200D) which led many video blogging enthusiasts to have a strong aversion to this camera.  T5i has continuous auto focus during video recording.


It would be total injustice to compare an entry level T5 (1200D) with mid or professional level photography cameras like 80D, 7D, 5D Mark II, 5D Mark III, etc. These cameras have fantastic AF, newer processors, higher resolution view screens, fast burst rate, high ISO performance and many more features. But they cost way more than a T5, so we get what we pay for!

Be a DSLR Ninja.

What's the relationship between between ISO, Shutter speed, Aperture and Light in photography?

Photography is a word having Greek roots, which basically means "drawing with light". When I started doing digital photography few years ago, this did not make sense to me at all. How can you make a picture just using light? Only light matters? My pictures were blue, black, red and washed out all the time, but I didn't feel like giving up. It took me a fair amount of time to understand controls such as shutter speed, aperture and ISO which was the outcome of non stop reading and a lot of mistakes.
Coming back to the concept of light, it started to make sense when I attended a film photography workshop couple of years ago. The dark room with very dim or near to zero red lights was a whole new point of interest for me. My partner and I made a pin hole camera out of Pumpkin. Here is an image of our pinhole camera, sorry for making my pumpkin look upset. ;)

Picture from photography workshop
Pin hole camera photography workshop

This workshop made me understand how important light is when taking pictures, and the rules apply to both film and digital photography. Basically the value of ISO, Shutter speed and Aperture directly affect the amount of light hitting the sensor. This light gets transformed into an image by sensor circuitry. A short and crisp way of explaining the light variation whenever one of these values is changed is shown in the image below.

ISO, Shutter speed and Aperture in photography
Relation between ISO, Aperture and Shutter speed in terms of light. 
The tricky part here to understand here is how to vary each of the above three things simultaneously. A couple of quick examples:
1) Sunset landscape shot: Low shutter speed for more light, high f stop for more details. Yes, high f stop would minimize the light, but shutter speed would cover up for it.
2) Bike racer daytime action: Fast shutter speed to freeze action. F stop as low as possible to make background out of focus. But if image is too white, then only solution is to increase f stop so as to control the incoming light.
Quick tip: When to vary ISO? Well, depends on the situation. Example: A dancer inside a low light room. If the amount of lowest feasible shutter speed (to freeze action) and lowest f stop are not able to provide properly exposed shot (hard to see dancer's face), then ISO becomes a life saver.

Hope this post would help you to fiddle around with these 3 main settings. The variation style mentioned in this post is applicable for Manual mode shooting.

Be a DSLR Ninja.

How to make your own product photography light tent for cheap?

Have you ever bought a product from eBay or any other online store? Notice how the images are so crisp, sharp and properly lit. Well, the magic wand behind those professionally looking photos is a soft box, light box or simply a light tent. The whole purpose of having a light tent is to spread the light evenly in every direction. Why? Photography is all about light. A light box minimizes issues such as shadows, harsh blown out edges (from flash or direct light) and faded color. 
Now the difficult part, spending money. You can buy a professionally built light tent online around 70-100 bucks. More cheap? Buy used. More cheap? Do it yourself. Yes, that's the best way. Only thing required from you is a visit to your local market and a couple of hours. Here is a list of things you will need:


1) Old used cardboard box or moving box. Any color would do. Preferably 18x18x16 inches. 
2) Cello tape or any other kind of tape. Duct tape would also work, I believe it works for everything.  
3) Tissue paper or a white muslin fabric/cloth. 
4) Cutter. 
5) Three table lamps. 
6) Three 80W or 100W fluorescent or daylight bulbs. 
7) A pen or pencil for marking. 
8) White poster board. 

Before we start, I request you not to scream with joy ( I did) looking at your product pictures after finishing the light box set up. Let's do it:

Step 1: A cardboard box has 6 sides, out of which one is already opened in order to take out whatever product was in it. This would be the entry for placing the product. Also, do not touch the exact opposite side to this opening. 
 Step 2: You have 4 sides remaining now. Choose any 3 sides of your choice and make square shaped gaps by using cutter. 
a) If you are using a tissue paper like me, take a pen to mark the gap size required for a tissue paper to fit. This cut would be smaller as tissue paper has a limited and fixed size.  
b) If using a white muslin cloth, you can cut as much big as you want leaving some space on the edges for cello tape to sit on. 

Step 3: After finishing the cuts an any three sides, all you have is a box with three sides wide open. You can put your hand or arm or even face through that gap into the box, just to have some fun. Place the tissue paper on top of gap, hold it firmly. Grab the tape and apply on all 4 sides. Do similar thing for remaining 2 sides as well. 
If you were using a white muslin cloth, cover up the whole gap and fix using tape on all four sides of cloth. Do similar step for remaining 2 sides. 

Step 4: Did you notice you still have 2 sides intact out of total 6? One would be your product background and other one as the box base. Tilt the box and place it in such a way that you will have gaps on top, left and right side. Take the white poster board and place it inside the box in a sliding motion. It needs to form a curve. Fix with tape. See picture below:

Product photography light tent
Light Tent or Light Box ( Not finished yet)

Step 5: Bring all three of your table lamps containing day light bulbs close to left, right and top gap. Turn on the power. Voila! 

Place any suitable sized object inside your light box and take brilliant quality product pictures using your DSLR or smartphone camera. 

Here is a sample shot:

sample test product photography image
Sample Product Photography Image

Be a DSLR Ninja.