Friday, July 26, 2013

Picking lenses based on Focal lengths and Sensor sizes

Good Friday from Prospect
1.5 Crop Sensor
Today I want to talk about lens focal lengths and the apparent differences when placed on cameras with different size film/sensor planes.
This refers to the surface area not resolution. This post is as much about image production and ultimate image feel as a discussion of hardware.

It took me a bit to get my head around this, when I moved to digital from film, since everyone obsesses about crop as the most important variable when choosing a lens.
This is where it threw me.
When I select a lens, the first factor is it's ability to compress or expand a subject. For instance I shoot portraits using a compressed, telephoto, focal length, not an expanded one. The flatter the subject can be the more attractive the outcome (there is of course a sweet spot but that's more subjective than technical). When using, what I call expanded focal lengths, wide angle, you distort your subject by pulling them forward from the background, which by the way also effects a face making it look deeper than actual dimensions.
The other factors like wide open apertures, fast glass for low light, bokeh, IS, filter sizes etc are the next deciding factors but not what we're discussing here today.
My division between the two is this. above 50mm = compressed, below 50mm = expanded. Focal length numbers from the lenses, period. 50mm is the zero point that acts like both, depending on the distance from your subject.
Full Frame Sensor
Focal Length Explained
First, You need to forget about the "crop factor." The focal length of a lens and its accompanying perspective characteristics don't change just because a lens may be mounted on a crop sensor camera. The crop area has absolutely nothing to do with the lenses characteristics in producing an image. A 100mm lens on a 35mm 1.5 crop, full frame or a medium format has the same result. Great compression and wonderful Bokeh at open apertures. 
The only time it should matter is when you are composing your subject and how close/far you are standing from that subject and how much stuff you want in the frame.
Yes it is true that in a small interior space you want to get as much as you can in the frame. But using an equivalent "crop factored" lens does not produce the same result.

Here's an example of the effect of different focal lengths and there equivalents. 
Shooting your subject up close with an ultra wide (like a 14 or 12mm) pushes the background farther away giving you that super depth effect you want with an ultra wide. They also allow more content in the frame. A 14mm is suggested to be a 21mm on a crop sensor so you would need to use a 9.5mm (approx.) on a 1.5 crop sensor camera to achieve the same frame using a 14mm on a full frame sensor camera.. Problem is in the real comparison. An image produced with a 14mm is vastly different than a 9.5mm. Perspective, although deep, is usually very distorted with a 9.5 (almost fisheye) than a good 14mm ultra wide. Two different animals entirely. Lens distortion does not change because you cropped in your photo, just the apparent visual effect because you don't see as much content in the composition. Same can be said in comparing a 35mm vs a 50mm. People can look very weird shot with a 35mm up close compared to a 50mm which is what our eye sees (subjective arguments not with standing).
One notable difference between full frame and crop sensor is the difference in distance between you and your subject, to achieve the same composition. You need to step back with a crop sensor camera to achieve the same framing as a full frame.
That does change a number of settings and ultimately the outcome of your image, like real depth of field. Those differences are for a discussion between full frame and crop cameras. Later.

Tech Note
Focal length refers to the distance from the main lens element to the film/sensor plane, period. Whether you are cropping it down or not, the lenses characteristics are still the same. And that plane distance calculation remains the same whether it's a full frame 35mm or 1.5 cropped sensor (or even medium format). 
This brings me to another factoid, how your subject will look in relation to what the human eye sees and what views more realistically. For instance the human eye actually sees the equivalent to a 22mm, not a 14mm cropped in, when discussing total input including the periphery but 50mm is what we see in the middle, not 33mm cropped in. 

f 2.8 crop sensor, fuji 35mm f1.4
(original size 3264 x 4896-XPro-1)
click here for high-res
Point 1 This point is the most important in relation to your subject matter. It relates to depth of field as much as perspective.: Focal length affects perceptual perspective. As the focal length and magnification of a lens increases, the image appears more compressed, resulting in less visual distinction and separation between the foreground, middle ground, and background. This is also the most important factor when attempting good BOKEH. Good bokeh allows you to create images with content awareness and focus with few distractions (what compositional focus is about).
f 2.8 full frame sensor
canon 16-35 II f2.8 at 35mm
(original size 2912 x 4368 - 5D mk1)
click here for high-res
Point 2 This is what everyone seems to be concentrating on. Crop factor: Ignore your crop factor when choosing your lens. The beauty in focal lengths in not the crop for composition, it's the subject itself and the perceptual perspective.
f 8 crop sensor , fuji 35mm f1.4
(original size 3264 x 4896-XPro-1)
click here for high-res
Point 3 The misdirection of crop factor effects on focal length is merely that, mis-direction. A subjects distance to film/sensor plane is what makes an image either sharp, or in focus. The lens has a better capacity to produce sharp images when the plane is closer to the subject, not unlike your own eyes. It's easier to see things in detail up close than far away. So in that point all 85mm lenses on any camera should produce the same detail and fidelity whether you crop it down or not, taken from the same distance to subject.
f 8 full frame sensor
canon 16-35 II f2.8 at 35mm
(original size 2912 x 4368 - 5D mk1)
click here for high-res
The samples on the previous post show that explicitly although I'm going to show it clearer here.
Those images where shot using only two focal lengths at the same distance from the subject. The only differences are the amount of excess image the frames carry due to the area available on the different sensors.

Point 4 Lastly It's always about the glass. Good glass on a sub camera produces better images than a crap lens on a good camera. So take your time in picking what's right for you. What are you shooting and what are your desired results are the two most important factors in choosing lenses.

Hope this helped.
Enjoy Derek

Wednesday, July 24, 2013

Shoot the Moon made simple... No Mumbo-Jumbo

Happy Wednesday from Prospect.

Here's the simplest description of how to shoot the moon.

I've recently viewed a lot of overly complicated how to's to shoot the moon. Everyone goes on about how hard it is to shoot.

It's simple. Don't shoot it as if it were night. It's high noon on the moon so shoot it as if it were the middle of the day.
Heck, you could probably shoot using the rule of 16 and get it. Or at least be close.

Original HighRes Jpeg (5616 x 3744). Canon 5D mark II, Canon 70-200 II f2.8,  ISO 320, f5.6 at 1/500th
High focal length will help for detail. 200mm plus will work, aperture should be at the lenses sweet spot (f2.8 lens is usually f5.6 or f8). Shutter should be no less than the focal length, 200mm = minimum 1/200th sec. ISO around your usual for daylight. 400 usually works well.

The shot you see in this post was shot at 200mm, ISO 320, f5.6 and 1/500th, hand held (no tripod, although it would't hurt to stabilize at that focal length.

I cropped in as much as possible afterwards to get my composition and converted to black and white. Done.

If you want this kind of detail with a night shot of skyline then you need to shoot two shots for correct exposure and marry them in your favourite editing software,

Thinks about it. That moon is at least 2 stops brighter than dusk. I mean it's high noon up there with the sun straight on the surface and reflecting at an acute angle to us.

Anyway, hope this helps, it did for me once I got the duh moment over with.

Photos below compare two f-stops (5.6 is the sweet spot for this one)

Enjoy, Derek
100% enlargement of original jpegs. f4.0 on left, f5.6 on right (sweet spot)

200% enlargement of original jpegs. f4.0 on left, f5.6 on right (sweet spot)

Friday, July 5, 2013

DSLR vs Mirror-less? Really? My introduction to mirror-less photography...An eye opener

Good Friday from Prospect. Looks like summer has finally found us, and it's hot.

Today's post is more on the review side than anything else. I don't do reviews as a practice but if gear falls into my hands I'm all about it.

For those of you who have been following me for a while you'll recall I purchased a Canon G1X in April of 2012. I was looking for something light weight that gave me decent resolution on a C-size sensor that had the manual controls I need when I shoot but would be light and fit in a small case or pocket. Unobtrusive.

Canon 5D mark 1 50mm f1.4
click here for full size jpeg
My choice at that time was that G1X and for the most part it gave me what I wanted for a reasonable price. The kit, with filter adapters and such, took me into the under 1000.00 range. It has fully manual adjustments using readily available dials and buttons right on the body with almost no need to go into menus. It has 2 Custom, saveable setting groups for quick set-up, not unlike my Canon 5D M2. Sensor has a ratio of 1.8, slightly smaller than a typical C-size DSLR at 1.5 crop. Lens was a fixed zoom at 15.5 - 60mm (28 - 115 approx) with an aperture of f2.8 - 5.6.

This camera worked well for me and introduced me to mirror-less cameras without a big bundle out of pocket and no fuss about glass. I've shot everything from the Route Halifax Saint-Pierre race to the Tall ships primarily for this blog with potential to print (resolution is 14.3mp and shoots jpeg + RAW).

Canon 5D mark 2 Sigma 50mm f1.4
click here for full size jpeg

But as any photographer will tell you, stick to the gear you have and only move as you grow and can afford. At the time of my purchase I was trading/selling all my Pentax gear (that story is in the past and you can read about it HERE).

So the cost wasn't significant. But at the same time the Fuji X100 and XPro 1 were out at a significantly higher investment and just didn't fit what I was looking for at the time. I needed to learn what the fuss was about.

Now fast forward the June 2013. Time to move up. I had the G1X long enough to understand what I really did and didn't like about that camera and knew what I wanted. 

Fuji XPro-1 Fuji 35mm f1.4
click here for full size jpeg
I have no issues about the whole mirror-less concept, which as far as I'm concerned it is just a reincarnation of the range finder with a live view LCD on the back. Call them point and shoots if you will but that really doesn't describe them. I know of a bunch of DSLRs that fit that point and shoot description. If you're sticking your camera on auto everything, regardless on interchangeable lenses, it's a point and shoot. Hell, a cardboard, film,  pin hole camera is as close to a point and shoot as you can get.

Canon 5D mark1 Canon 16-35-II f2.8
click here for full size jpeg

Now to the review part. The problem I had with the Canon G1X was, to be honest, minor to most. Manual focus was truly non existent, the optical view finder is a joke and if I wasn't shooting stand still subject matter it just fought focus all the way. You need to really think about your focus and framing beyond the usual. Simply zooming in ever so slightly to reframe would change your aperture which would adjust your depth of field which would change your composition and on and on. Not cool! But it did have a leaf shutter and if I were to use it in a studio setting that would work. But that's not what that camera is about. They're about shooting without flash, for the most part, with available light. Street photography is where they belong.

Mind you, once I took the shot it gave me above average quality. I do compare these to top end DSLRs, that I use to put food on the table, so I'm a lot fussy.

Canon 5D mark2 Canon 16-35 II f2.8
click here for full size jpeg
Well I'm glad I chose this route of seeing if I could really rely on such a camera. June I traded in my G1X for a Fuji XPro-1. The pricing has dropped significantly and the control and quality are stunning.

Some say they are willing to give up their DSLRs for this camera. I can't say that much, unless you're comparing any of the crop sensor DSLRs on the market today. Then yeah, dump em.

I shoot with full frame Canon 5D M2 and M1. Those full frame sensors are tough to beat. They're not about resolution (being 21mp and 12mp respectively) they're about fidelity. They're about buttery mid-tones and smooth flesh-tones. And nothing beats full frame for Bokeh, especially with the right lens. 

But I've gotta tell ya this thing just performs. I doubt, IMHO, there is any C-size DSLR that can knock this camera off it's pedestal. It has every control at your finger tips, 16mp res on Fuji's new xtrans CMOS, c-size sensor. That means no anti aliasing filter in from to blur the image to get rid of moire. If you're not sure what that means it simply means sharp images right out of the gate without weird patterns from things like clothing patterns, house siding and fences to name a few.

I've posted 6 images on this post with links to the full high-res for you to view. All high res Jpegs exported from Lightroom with nothing more than  a watermark and identifying titles. All were shot in manual mode as set by one of my hand held incedent light meters to make these fair. All were RAW+jpeg modes in fine at 2000/sec, f4.5 and ISO 200. The lenses I used were Fuji's 35mm f1.4, Fuji14mm f2.8 on the xpro 1,  Canons 16-35 II f2.8 and my Sigma 50mm f1.4 (best 50mm lens on the market, bar none, IMHO) on the mark 1 and 2. The only unfair thing here is the 16-35mm ( Only wide angle I have for my Canons. I don't own the Canon 14mm f2.8. Just don't have that bread). It is a zoom which inherently don't produce the sharpness of a prime lens so the real comparison is the 50mm vs the 35 (53mm on fuji crop sensor, sort of).

Fuji XPro-1 Fuji 14mm f2.8
click here for full size jpeg
I did notice that the fuji raw from sensor colour balance is a bit colder than the Canon ones (maybe it's just how Lightroom translates the raw file). But quite expected if you are familiar with fuji as a film company. It's where they live in colour balance. I made a point to not adjust it to be fair. The colour rendition of the jpegs are much closer but since each camera modifies the image to produce the jpeg, and I've adjusted my set-ups to be closer than default, I thought that didn't make a good comparison.

I've also included a screen shot of file sizes from the three digital cameras at my disposal. If the RAW file sizes are any indication of information these are chalk full of data. This is definitely game changing technology.

Anyway you be the judge. I'll be carrying this thing every where and should be at a full comfort level real soon.

If you have any comments don't be shy. I'd love to hear them.

Enjoy, Derek