Sunday, October 4, 2015

How to identify lenses with marking on it?

How to identify which lens is for full frame and which one is for crop body from various lens manufacturers …..

Here is the quick guide for all ….

Crop Body Lens: There is clear marking on the crop body lenses with “DX” (stands for digital sensor). Every crop body lens of Nikon carries DX word on it. But mind you there is no DX mark on their crop sensor camera bodies.

Full Frame Lenes: Surprisingly, there is no marking on their full frame lenses. So if you “DO NOT SEE” word “DX” on any Nikon lens, for sure its a full frame lens. Surprisingly, Nikon Full Frame Camera Bodies carries word “FX” (stands for Film Sensor) on their camera bodies to make then stand out.

Crop Body Lens: All crop body lenses of Canon are marked with word “EF-S” (Stands for "Electro Focus Short”) or "EF-M".

Full Frame Lens: All full frame lenses of Canon are marked with work “EF” (Stands for “Electro Focus”) only. Also there is a another “L-Series” line up of lenses which are for FULL FRAME only & they ultra expensive due to the specs they offer (like f/1.2 apertures) where word “L” stands for Luxury …. one of the Canon user told me this :) 

Crop Body Lens: All crop body lenses of Sigma are marked with word “DC” …. i guess it stands for DIGITAL CROP. 

Full Frame Lens: All full frame lenses of Sigma are marked with word “DG” ….. have no idea what that means. 

Crop Body Lens: They follow Nikon symbology and mark crop body lenses with word “DX

Full Frame Lens: Like Nikon full frame camera bodies, they are marking their Full Frame Lenses with the word “FX

Full Frame Lens: Now Tamron came with some thing odd to identify their lenses line up so i have to mention full frame here first. They mark their full frame lenses with word “Di” (Digitally Integrated)

Crop Body Lens: They mark their crop body lenses with “Di-II” …. i don’t know why they add mark II in the end to make them for APS-C sensor.

-Samyung / Rokinon / Bower- (One company …. same product with 3 different names)
Crop Body Lens: They mark their crop body lenses with word “CS” (stands for Compact Sensor)

Full Frame Lens: There is no marking for their Full Frame body just like Nikon full frame lenses.

-Carl Zeiss-
Crop Body Lens: There is a new line up for the crop body lenses under the name "Touit lenses” ….. & the good news is that they are Auto Focus :) …. There are other lenses for APS-C format but with different marking. 

Full Frame Lens: There is no marking for their full frame lenses

Crop Body Lens: Their crop body lenses are marked with “DA”. 

Full Frame Lens: They mark their full frame lenses with the letters “DFA / FA". 

Crop Sensor Lens: Their crop sensor lenses call sign is “DT or E". 

Full Frame Lens: Not able to dig out what their full frame lenses marking is. Please post in the comments if any one knows about it. 

Crop Body Lens:NX

Full frame lens: Is there any full frame from Samsung ?????

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Friday, September 25, 2015

Human Eye ... a 576MP marvel .... but u need only 7 :)

Today i came across a very interesting video about a camera lenses which is compared with Human vision. Human Eye ..... A medical marvel ..... only God/ALLAH can create. Ask any medical students/Doctors how difficult an eye internal structure is. 

I am sure many of you have came across a post which says that human eye resolution is 576 mega pixels .... Right! Ever wonder how this number came up? It was calculated based many factor which you will find on below link. 

The eye is not a single frame snapshot camera. It is more like a video stream. The eye moves rapidly in small angular amounts and continually updates the image in one's brain to "paint" the detail. We also have two eyes, and our brains combine the signals to increase the resolution further. We also typically move our eyes around the scene to gather more information. Because of these factors, the eye plus brain assembles a higher resolution image than possible with the number of photoreceptors in the retina. So the megapixel equivalent numbers above refer to the spatial detail in an image that would be required to show what the human eye could see when you view a scene.

But here is a surprise ..... out of those so called 576 Mega Pixels, we need only 7 Mega Pixels to view any thing/scene or stare in general .... & besides that one stare we need only 1 Mega Pixel to view the surrounding which mostly ignore by our brain including nose and glasses that are coming in our vision but our brain ignores it. Cannot believe it? .... Close your one eye & see.  Check out below link for a very interesting video explaining much more on this. 

Ok ..... Enough with the resolution. Now lets talk about focal length which caused me to writing this blog. 

If we try to replicate our eye focal length range into one lens, it is impossible at this point in time. May be in future any technology advancement can do that .... just may be. Our eye can see as wide as 150 degree which is equivalent to 5mm super ultra wide angle lens .... to .... recognising the small letters in book which is nearly 1 degree equivalent to 2500mm super ultra telephoto lens. So you getting the extreme dimension here .... from 5mm <----> 2500mm ..... all variation of these focal length is happening inside our eye. Now thats a medical marvel. I doubt i able to see any such lens at least not in my lifetime which can vary to these extreme values (in a single housing). Adding further, then we try to focus on a letter or a face, the 1 degree view kicks in (with 7 mega pixel resolution of course) and image made on "Fovea" which is a pitfall over a Retina inside of our eye ball .... a very tiny spot which is made of hundreds of thousands of optical nerves and other stuff (medical student s/Doctors knows what i am talking here). 

On the other hand, if we are standing still and trying to move around our eyes we can see almost 150 degree of view (equivalent of 5mm lens) which makes 576 MP of "snap shot" (in theory) but our eyes are capturing not a snap shot, they are constantly streaming live video stream  as mentioned above at many frames per seconds using 2 streams (2 eyes) and BRAIN process them one by eliminating unnecessary stuff like nose and glasses and this happening 24x7x365xYour total life. Even right now you are reading this line using 7MP of your eyes resolution and almost 2500mm of equivalent of focal length "Settings" inside of your eyes .... ignoring the rest of the screen  & world (or shall i say ignoring the rest of the 569 MP of your eye) of your laptop/computer/mobile. 

In last, there is a "general setting" of our eye which is called central retina which is equivalent of 38mm (50 degree) . Note that this focal length is vary from person to person ..... say from 28mm ~ 40mm. But in general its scaled mean value to 38mm. This is something you are viewing any thing in general or sitting in the cinema and trying to get back row seat to get complete view of the screen ..... rather then sitting in the front row and constantly move your head left to right trying to grab the movie. This focal length is basically derives the famous 35mm focal length on which almost all of the world MOBILE CAMERA are calibrated. Thats why all photo journalist prefer to work with 35mm focal length prime lens because it gives more of realistic view of any normal human vision as what we see & how we see the world. In short ..... 35mm focal length is the most used focal length in human history. 

Actually below image caused me writing this blog which was from a paid workshop over Nikon lenses from famous photographer John Greengo. Later i did some google and added couple of links above to add additional human eye mega pixel flavour to make something interesting & some additional info for learning purpose. 

Now just think for a second .... how much powerful human eye is. How the mighty one created something that we as a human is yet to discover and understands many hidden feature of human body. 

Till next time ..... Happy Learning Guys !

Babar Swaleheen
BBM Pin: 75DEED40

Saturday, March 7, 2015

35mm Prime Shoot Out ....

So the other day one of my friend at work who owns multiple Zeiss lenses, was telling me to go at least ones in my life for Zeiss lens and test it. So i took the liberty and asked him to lend me his Carl Zeiss Distagon T* 2/35 ZF.2 lens. Note that Carl Zeiss makes only MANUAL FOCUS LENSES

I took the lens in the office and had it coupled with my D810. Then i requested another friend of mine at work and asked him to be my model which he happily did .... and i was blown away with the image that i had from the Zeiss :) 

Note that this image is right from the camera (SOOC) and no editing or retouching done. Not to mention that Carl Zeiss makes only manual focus lenses. Hi-Res can be viewed using this link.

After watching the Zeiss performance i thought to start compare it with the 35mm that i own (two of them). I have one cheap glass from Samyung 35mm f/1.4 & another is old pal from Nikon 35mm f/2D. Then i requested another friend of mine to give me Sigma 35mm f/1.4 Art series lens.

Note: Being a Nikon shooter you will not find the canon in the below list. So Canon shooters can stop reading here if they like.

Now i have following 4 champions to compare .....

Carl Zeiss Distagon T* 2/35 ZF.2 (S1000)

B- Nikon 35mm f/2D ($330)
C- Sigma 35mm f/1.4 DG Art Series ($900)
D- Samyumg 35mm f/1.4 ($400)

So i have tested the famous photography term "BOKEH" first .... because thats what these lenses are famous for. I coupled each of them over my D750. I went outdoor near by park with some far street to have them as a Bokeh. First i choose flower first as a foreground subject and the street light to have some Bokeh. But due to heavy wind, the flower was constantly swinging and i was not able to capture the flower tek-sharp even at higher shutter speed. 

So later i decided not worry about much over the foreground subject sharpness and focus only at the Bokeh at the background. For the sharpness i have done indoor test shot which you will find below in the end. 

So here is the first Test shot of the Bokeh from lens-A (Carl Zeiss Distagon T* 2/35 ZF.2)
You can download this file using this link

Followed by lens-B (Nikon 35mm f/2D)
You can download this file using this link

Followed by lens-C (Sigma 35mm f/1.4 DG Art Series)
You can download this file using this link

Finally lens-D (Samyung f/1.4)
You can download this file using this link

Now surprisingly i have found Nikon 35mm f/2D the "least" minimum focus distance (0.85 foot) in compared to the rest of the 3 which all got 1 foot, thats why you can see bigger Bokeh created by Nikon lens even @ f/2.

Now the next topic is Sharpness. How Sharp each lens is .... lets find out. 

But before we head for the comparison, note that i have used my camera in manual focus mode, used the "live view" and "zoom +" button to make sure it is really sharp and then took the shot. The camera was in manual mode with AUTO WB & AUTO ISO. Aperture was open to maximum for all 4 lenses. 

Here all 4 lens sharpness in one shot to compare. 

Zeiss result
You can see the Hi-Res file using this link

Nikon result
You can see the Hi-Res file using this link

Sigma Art Series result
You can see the Hi-Res file using this link

Samyung lens result
You can see the Hi-Res file using this link

All offers heavy vignette at the maximum aperture except Carl Zeiss which offer least vignette & this shows the clear superior optical quality and colour rendering offers by Carl Zeiss distagon which is a manual focus lens. In this world .... quality comes with a price and you will be paying the most to get the best which is Carl Zeiss. But will you able to sacrifice the auto focus thing against the superior optical quality .... at the heaviest price from the list?  I am just wondering .... if this normal Zeiss lens is performing top notch .....Imagine how OTUS going to deliver the quality !!!!!!!

But ..... in my humble opinion ..... all this comparison comes down to your budget & your skill set. I have shooted images with all 4 of them. Apparently the most low quality colour rendering lens among the list is Samyung which producing yellowish tone image and it also a manual focus lens (second cheapest among the list). I have some stunning & tek-Sharp images from it. Take a look on a sample image using this link. You already experienced the Zeiss result at the top of this blog. Then i left with Nikon & new Sigma Art Series which i will check later in detail

Honestly speaking the most budgetary lens with better sharpness even @ f/2 (due to less focus distance) and able to deliver most contrasty images is Nikon old Pal .... 35mm f/2D. Not to mention it can Auto Focus but only over full frame & D7X00 crop bodies. No Auto focus offers over D5X00 & D3X00 crop bodies.

On Long term basis, Sigma is not a good choice. Even it offers superior optical quality and Auto Focus ability and with little less price with almost near-to-quality to the Carl Zeiss, but they are made for the current generation of the camera. Imagine if you change the body after few years and if not work on the new one? Atleast with the similar brand lenses, you have very very rare chances of compatibility issue.

Hope you all will find this blog interesting & help you choose the best 35mm lens as per your taste & budget.

Happy learning Guys.

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Tuesday, February 10, 2015

Nikon vs Canon ..... heads-on

The legendary war between Nikon & Canon .... it was there even before the first world war .... and its still here as i am writing this Blog ... 

Well so whats new in this blog .... well lately i have done something not regular .... As most people know i am one loyal Nikon user .... i bought Canon 7D mark II .... why ? because now i want to explore the other side of the window .... As my most countryman yelling about Canon all the time .... and act as a die hard fan .... so want to see whats so much special about Canon ....

(Note: This comparison is only for the sensor performance .... nothing more .... i am not comparing 7D mark II AF system or any other parameter with Nikon)

So buying canon body is not the only thing i did .... you need lenses .... for normal usage i have the famous lens that almost all canon user have with their full frame bodies hooked up all the time .... 24-105mm f/4L lens .... but over the crop body of 7Dmk2 i am not able to get the most from the lens due to the crop factor of 1.6

Any ways ... lets cut to the chase ....

Today i have compared the 7Dmk2 crop body sensor with Nikon D750 !!!!! ...... wait a min .... how can i compare the crop body with full frame body ??????  Right ...!!!!

Well first off .... i dont have any Nikon crop body .... sold my D7100 long time back .... and then i have done something extra with D750 .... i have used my D750 full frame body in "DX" (crop mode) so instead of using the 36x24mm of the sensor area .... camera only use the 24x16mm sensor area which behaves exactly like the crop body in terms of Dynamic Range and ISO performance etc etc

I have used the famous Nikon wide angle lens 14-24mm f/2.8G lens which is the optical marvel in our present time and delivers the sharpest details across all the aperture values. So that lens is works fine over the Nikon body and deliver all the lens EXIF details from the lens CPU to the camera body which you will find the RAW file that i will be sharing in the end of this blog.

What about using this lens over the Canon body?  ....

Well for that i have used special adaptor which is called "Fotodiox Lens Mount Adapter" using which you can use any Nikon lens (G-Type or D-Type) over Canon body. The beauty of using this adapter is, you can control the aperture opening. Obviously you cannot dial-in the exact aperture value like f/4 or f/8 etc .... but you can easily dial f/2.8 or f/16  .... by fully open or fully close the aperture ..... sweet right :D ... well for other value, you needs practice ... thats all i can say ....

Here is the link for this adaptor along with the details ...

Fotodiox Lens Mount Adapter

So ones you mount the adapter over the canon body, you can easily mount the Nikon lens on it and then start shooting.... obviously you not able to see the aperture value which you need to manual adjust by moving the blue knob (showed in the video how to do it) .... but i was kind a surprise to see the 7Dmk2 internal camera meters the scene and was telling about the scene for its exposure. Based on that i had adjusted my ISO & Shutter speed which you see in the below images ....

After i have adjusted my Nikon D750 into DX mode i have shot some sample images and then shot the same scene with canon 7D mark II ..... used the same lens Nikon 14-24mm f/2.8 on both bodies ... and used the same  Aperture, ISO & Shutter Speed for the shots .... lets start looking at the images below .... note that the images on the left is from Canon 7D mark II and the one at the right side is from D750 (in DX mode).

Images at left from Canon 7D mark II & right from Nikon D750

at 100% Zoom 

So you can all witness the Canon 7D mark II sensor performance here from the above images. I tried to be neutral as much as i can but still if you guys have any doubt ... I am sharing the RAW files of these 2 images (one from Canon & one from Nikon) to play with and see the result by yourself  and see who is the winner .... its you photographers who going to decide .... Not me :D

I also shot a small video for this test that i had done using Nokia Lumia 1020 :)  ... you can watch that video using below link

Testing Canon 7D mark II sensor

In the end i like to add one note here. The newly announce Canon MP monster 5DS/5DSR are both build on the same pixel pitch of 7D mark II which is "4.1┬Ám" . So if you think 7D mark II sensor is not upto the mark when it comes to recovering the details from underexpose images ... Then dont expect much from 5DS/5DSR due to the same pixel density.

You can download the sample RAW files & the above comparison images in Hi-Resolution using below link.

Sample RAW Files from Canon & Nikon

Thanks for reading this blog. Hope you guys fine this blog informative.

Happy Learning Guys !!!

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