Monday, August 31, 2009

Unhappy with shutterfly photo scans

In 2006 I had taken a bunch of film photos and had them processed by shutterfly. Shutterfly also scanned these photos and put them in my account so I was happy. Finally this year I decided I wanted the scans on my computer and I ordered a DVD of them (you can't download the hi-res versions from the website). I was unpleasantly surprised when I got the scans back. They are 270 ppi or so, amounting to 1536x1024 from 35mm film. I would have expected something more detailed from them such as 2000 ppi or so. But it was a bad surprise as some of the photos were landscapes and I was looking forward to enlargements. I guess I'll have to dig out the negatives from the boxes.

Saturday, August 29, 2009

D40 : Burst mode test

Kingston SDGC 4GB class 6 (SD6/4GB) card. Auto focus (Prefocused by half shutter press before burst). Auto mode. Large/Fine Jpeg. Off white wall with a few objects on it.
23 pictures in 11 seconds. Buffer sat at around r4/r5 during burst. After burst the card activity light flickered for about 4s.

Friday, August 28, 2009

The D40 and the F65

My own first SLR is the Nikon F65 which I got in 2001 for about $400 (more than my D40!). It was billed as an entry level SLR for beginners. That's me, a beginner for about a decade now. I've used a digital compact (Canon A510) since 2005 and details of the F65 slowly faded from my mind as it stayed stashed in the closet. But after I got the D40 I began to remember things - didn't it have a DOF preview, didn't it have this? That? So I got it out of the closet and lookee here, the F65 (Nikon entry level film) has:
  1. Depth of field preview
  2. Exposure bracketing
  3. Five (5) AF areas
  4. Pentaprism
  5. Top LCD
It doesn't have two control wheels, but has the control wheel + modifier buttons.

Hmm... methinks the Nikon engineers are losing to the Nikon marketing people (C'mon DOF preview, exposure bracketing, 5 AF areas these don't add to cost - they probably COST money to take away, the only reason to take these small things away is to make people buy the more expensive one isn't it?). The pentaprism is cost and weight, and the top LCD is redundant.

Hmm...

I was reading an essay by a photographer who shoots 4x5 format for landscapes. Its very entertaining to read about how he focuses on a ground glass screen and then uses a loupe to check focus. But here's a sentence that I found entertaining because its technically wrong, but I think I know what he means:

"Fourth, the inverted image on the ground glass creates a more direct visual impression because the brain does not have to flip the image upside down. This last remark is based on the fact that our eyes act as lenses and thus project an upside-down image of the world to the brain, which then has to flip it right side up. Because the ground glass image is inverted it is projected to the brain right side up thereby nullifying the need for the brain to rectify the image."

Its hard to explain why this is wrong but basically the brain is used to how it gets the images and it is harder for the brain to process an upside down image. Consider the empirical results that we find it harder to recognize upside down faces, and read upside down writing.

But I think what the author (Alain Briot) experiences is his brain reacting to the novelty of the upside down image. Because the image is upside down, and is harder to recognize, his brain starts to analyze the picture as individual components (note his use of the loupe to focus). At this stage of the artistic process he is trying to extract detail from little pieces of the image (hence his need for large format). The upside down image forces him to do this.

Thursday, August 27, 2009

D40 : Manual lens

I have a F65 which came with a 28-80mm lens. I used this lens on the D40. It required manual focus, the red focus dot did not work as a focus indicator and I could not select a focus area. (I had gotten the impression that the focus circuitry would still be working so that I could use the focus indicator to judge focus). The dot works. It just goes off when you are way off focus, flashes when you are close and is steady when you are focused. Now you know why my moon shot was out of focus and I was complaining that there was no red dot :P

The exposure meter still gave readings, and they looked sensible. Here are two shots of the moon. One with the kit lens at 55m and the other with the manual lens at 80mm with a UV filter on it. The 80mm shot is blurry, either because of my poor focus, or because of a cloud infront of the moon. I'm going to try some more shots later at night.

Kit lens at 55mm


Film camera lens at 80mm
This is the appropriate 1.5x magnification you expect from the differences between the DSLR sensor size and 35mm film.

UPDATE: I finally made a better exposure and got my manual focusing hands back:
1/250s, f6.3, 80mm (film equivalent 120mm), hand held

Tuesday, August 25, 2009

D40 on flikr

It was interesting that the D40 even beat out compact cameras from Nikon...
The link to the live page is here.

How fast a card should I get for my dSLR?

I couldn't find a scientific answer to this one. Funnily enough I couldn't even find online how fast the D40 writes out its data. Perhaps its in the manual and I should just look. And what's with all these different speed metrics for SD cards !?

Anyway, here's how I went about it. From yesterday's shoot I have 101 pictures totaling 204.6 MB (Large Fine Jpegs. I ain't no RAWer) = 2Mb/picture

The D40 can shoot bursts of 2.5 frames a second = 5Mb/s. If we are to keep up with that we should have a card that is capable of at least 5Mb/s write speed.

Thanks to wikipedia's page on SD cards, we learn that class 6 SDHC cards write at 6 MB/s and above and the 'x' notation e.g. 40x, 50x means 40x150kB/s.

So we will need a class 6 card doing 5MB/s or more or a 33x card.

Lets see how that works out for an amateur shooting like 10 pictures or so at a go.

The cost of things...

In 2005 I bought a 512MB SD card for $37. Now, in 2009, from the same company you can get a 4GB SD card for $9.

Sunday, August 23, 2009

D40 : Kit lens (18-55mm Nikkor Af-S G)

You need to watchout for depth of field at 55mm. I have to reprogram myself after 4 years of using a compact. I keep thinking f5.6 is 'Ok for things at inifinity, like that building over there'







But it ain't. You have to do tricks like 'hyper focus', i.e. focus at infinity (like a building behind this one) and then recompose, or stop down the lens more.

Lets actually work this out:
Circle of confusion (Zeiss formula)
c = d/1730
where d = sqrt(23.7^2 + 15.6^2) = 28.37mm
c = 0.0164mm

Hyper focal distance (Wikipedia)
H = f^2/Nc
For the shot I had
f = 55mm
N = 5.6

H = 32937.71 mm = 32 m

The building was probably 10-15m away, and I focused on that, reducing my DOF. I should have kept my aperture at around

N = f^2/Hc = 55^2/(15000*.0164) = f12 for a good shot.

Alternatively, I should have focused on the farthest part of the building, locked focus and recomposed.

Stop down the lens Kaushik, stop it down. This 'ere's a REAL camera :)

D40 : Spot metering and exposure lock

Metered on the sun reflection on the water and recomposed


Metered on the cobblestones and recomposed

Saturday, August 22, 2009

The D40 : Summary

The D40 is a great camera. It has spot metering, exposure lock and focus lock. These are important things for me because I like to play with pictures taken against light, which are challenging even for film. It's evaluative metering is superb, which is for everything else. I have no problems with the controls, though some people say they are cumbersome. At most, you have to hold down a modifier button while spinning the thumb wheel. The exposure lock button is the only inconvenient thing - you have to jam your thumb next to your eye as you look through the viewfinder. I haven't made prints yet. Theoretically 6 MP will yield 10"x 6.6" prints at 300dpi and 20"x 13" at 150dpi. We'll see how that turns out. The D40 is as light as my film F65 and lighter than the fancier older film Nikons. It feels solid in the hand, more solid than the F65. The kit lens (18-55 Nikkor G) is great, its quiet and has great depth of field. Be aware that you need to stop down quite a bit (f9, f11) if you want to keep a bunch of things in focus.

My Settings
  1. Setup->File No. Sequence->ON (other wise you will reset image numbering to zero each time you erase pictures from your card)
  2. Setup->Auto Image Rotation->ON
  3. Setup->USB->PTP (For Mac, to use image capture)
  4. Shooting->Optimize Image->VI (Vivid)
  5. Shooting->Image Quality->Fine jpeg
  6. Shooting->Image Size->L
Preferred shooting mode
When I have time to compose (e.g. a few seconds) I put it on spot metering, aperture priority and then play with aperture for depth of field, and spot meter at different image locations, lock exposure and recompose to get different exposure effects. I set focusing to single area (Custom Setting->AF-area mode->Single area) and enable focus lock (Nikon's famous half shutter press - Custom Setting-> Focus mode->AF-S Single-servo AF)
When I have to be quick, I put metering on evaluative, and focus on closest subject.

Specific Bravos
  1. Auto mode with no flash. The camera adjusts shutter speed to be handheld safe, opens up the aperture and then boosts the ISO as necessary to take the shot. Beautiful for cases when you don't want flash and are too lazy/have no time to adjust everything for a handheld shot.
  2. Low (and I mean LOW) sensor noise up to 1600ISO
  3. On camera image enhancement can be custom tweaked
  4. Spot metering
  5. Matrix metering is great (just like for the film Nikon)

Specific Annoyances

  1. Exposure mode needs to be changed through the menu
  2. Exposure mode not indicated in the heads up display

What I would have liked
  1. Exposure bracketing
  2. Time lapse timer
  3. Grid lines on viewfinder
  4. Mirror lockup
  5. Exposure lock button somewhere else
  6. An analog focusing meter OR a split prism focusing screen
  7. A million dollars
Did I mention, the D40 is great. I'm sure you can get cameras with the above 3 features and more. For a lot more money. I'm not a professional, the challenge of leveling the horizon, the challenge of playing with exposure, the challenge of playing with depth of field IS the fun, and the D40 is all I need.

Links

D40 : Depth of field

Having shot almost exclusively with a compact digital (Canon A510) for the last four years I forgot how much fun and challenging optics is.

The small sensor and the short focal length of the compact, much like older, rangefinder point and shoots (e.g. yashika mg-1) gave almost pinhole camera like behavior. Basically with these cameras infinity was about an arms length or so away and I would be more causal with the focus.

With the D40 its back to the F65 habits. Depth of field is back down (which is what I wanted). But I'm not used to it any more.

For this shot (click for full size crop) I thought "I'll just focus on them clouds there, the trees are at infinity, just like the clouds, it'll be all right". Not so. The trees look annoying because they are slightly out of focus, but you can see the sharp edge of the cloud. f6.3, 18mm. Shoulda stopped down the lens more.

In case there was any doubt, the kit lens can focus:

So I have no one to blame but myself...

Depth of field preview

The D40 has no DOF preview button. But, does a digital camera really need one? If you have time to stop down the aperture you have to to shoot an image, look at it in the LCD and decide - do I open up or close down the aperture more?

Thursday, August 20, 2009

D40 : Exposure : Sunsets

Original


Color and saturation adjusted a bit


A sunset? No.

Actually, this is not a sunset. Its a city rise. The red glow is from Revere, or one of those other cities to the east. This shot was taken facing east.

In short: The D40 can do sunset exposures just fine (These were all shot with aperture priority). Some shots were with -1 EV compensation.

The autofocus will work as long as there is even a tiny bit of light and the subject has contrast. I used the tree to focus, and this was nice and contrasty against the sky.

D40 mini-accessories

I got the Tiffen 52mm UV (Haze) filter and the Matin heavy duty LCD protector from the same company I bought the camera from. The LCD protector is one step up from the films you could get for your PDA. This is a thin sheet of polycarbonate that sticks to your LCD. I misaligned it at first and had to pull it off, and it came off without leaving any residue. It sticks quite well but is very reflective. In bright light I have a feeling it might reduce the contrast of the LCD. I plan to leave the protector on until it gets very scuffed, and then replace it leaving the original LCD scratch free (hopefully).

The Tiffen filter is cheap, its not multi-coated, so you can expect a little glare when you have a bright light source. An example is shown below:

The reflection is due to the UV filter.

The only other thing I want to get is a 4GB card. My 1GB card will store about 270 Fine JPEGs, probably half the amount of RAW.

Focusing screens for the D40

Yes, you can get them for the D40.

There's a very pricey one from Katz Eye. It runs into $100 to $155. It has some good reviews.
There is a pretty cheap one you can get on ebay right now ($34 with shipping), and it might be the same you get from focusingscreen.com (This one costs $40).

A video tutorial for replacing the focusing screen:


But I would use rubber tipped tweezers, rather than straight metal ones. And don't film your self doing it... :)

The google search url.

An amateur's review of the D40: Long exposure time examples

I am pretty pleased with high exposure times on the D40. The last time I really played with long exposure was with my film camera.

What I am NOT pleased with is MY inability to focus properly - aargh! But in my defense there isn't a focusing screen (like split prism, or ground glass). I wonder if I can get one of those for the D40?

Click on the examples to get a 1200px downsampled versions.



If you ignore my amateur focus you will note the amazing lack of noise even on 30s long exposures. I like this sensor.

In the last two pictures below I let the D40 decide the exposure and used aperture priority. The D40, like the F65, knows exposure. (For normal photos, on the F65, I ended up deciding to let the camera decide it. Whenever I took over I did something wrong. Only for special shots - like the really long exposures - did I put everything on manual. I think the same is going to be true of the D40.)

Its amusing though, these last two shots have the same exposure, but they are lit differently. It could be that the street lamps vary in brightness over time.

In short: great sensor!

Tuesday, August 18, 2009

An amateur's review of the D40: High ISO example

Picture (click to get a downsampled 1280px image). This was taken at sunset with 800 ISO setting with kit lens at 18mm zoom, no VR, handheld.



The overall impression is good, but is marred by the combination of hand shake and higher ISO that gives the photo a softness that hurts the edginess of the main subject. The auto focus was perhaps also not the best.

The following full size segments of the original image illustrate this point:









Thursday, August 13, 2009

Nikon D40 at different ISO levels

ISO 200


ISO 400


ISO 800


ISO 1600


ISO 3200

First impressions of Nikon D40

Obtained this as refurbished from Adorama for $375 with 18-55mm DX AF-S lens. Adorama shipped it for free and it arrived overnight (NY to MA). Its declared as refurbished but the body is blemish free. I would say this is a new camera (unless some one soaked the interior in dust/water/acid etc). There is a 90 warranty from Nikon on both lens and body.

From the exif information on the pictures I see that the camera has about 2600 shutter actuations, and the serial number has two dots punched in at the start and end. According to this page those dots indicate Nikon has refurbished the camera.

I found a few dust specks on the viewfinder. (Aiming at the sky and looking around the field of view). I remember on the old Nikons, that my uncle had, you could pop-off the pentaprism and clean it all out, but I don't think you can do that here.

The camera with this lens weighs about as much as my Nikon F65 (or N65), which is to say, less than a kilo.

The battery needs to be charged, but it had enough juice to go through the initial set up. It prevented me from taking any pictures though. Battery is charging, owner is pretending to do data analysis.

Things to do when battery charges (other than go grocery shopping)
  1. Look for dead/hot pixels on sensor
  2. Take shots at different ISO levels to see noise
  3. Evaluate exposure modes
  4. Look for dead/hot pixels on display LCD
  5. Evaluate auto focus accuracy
Things to buy:
  1. Plastic protector for the LCD screen
  2. UV filter (as protection) for the DX lens
PS. Sorry Ben, but I decided I wanted to see if the price premium on DSLRs was worth it over point and shoots. If I find 6 MP too restricting I might upgrade in a few years...

Wednesday, August 12, 2009

Moveable tabs on Firefox

I know firefox is so unhip now, with that chrome or plating or whatever they call it browser. But really, being able to drag a tab from one window to another? Nice.

Differences between Nikon pro and consumer DSLRs

It wasn't always clear from reading up on websites and forums what exactly are the differences between consumer DSLRs and pro DSLRs. I'm making a short generic list here of what Nikon pro cameras may have that consumer one's don't (listed according to how important they were to me)
  1. Aperture stop down to preview depth of field
  2. Fast mechanical shutter (rather than a combination of slow mechanical shutter and sensor gating which can lead to streaking in extreme situations )
  3. Exposure bracketing (shoot three or more shots in quick succession with slightly different exposure levels)
  4. 1/3 EV steps for ISO rating (i.e. pro cameras can do ISOs inbetween 100 and 200)
  5. Motor for AF lens in body (If you have many old lenses this counts as a cost savings)
  6. Metal body that can withstand physical shocks better
  7. Dust removal on the sensor
  8. More auto focus points
  9. Top panel LCD for settings summary
Basically, a "pro camera" is designed to withstand being dropped and bumped (you're in the streets covering a protest - it could get rough), has quick auto focus with many points (you're trying to shoot a guy shooting a hoop - you got zero time to focus and click), has many many MP (you grabbed the best shot you could, and the president's face is on the top right corner of the photo - you gotta crop it to 1/8th the size to make a good composition, will it still look good?), has better sensor protection (you're in the savannah, you just changed from a macro to a tele to snap a lion pouncing on a gazelle - you don't want to be bothered with sand on your sensor).

Me? All I really want is a little more than 3MP (my current Canon A510) to make nicer larger prints, greater depth of field freedom, and a little less of that annoying softness and blue fringing that comes with cheaper optics.

Also, as a random tidbit: if you want to compare a DSLR lens (made for the DX format sensor) to a film camera lens for the Nikon's the multiplying factor is 1.5. So the 28-80 kit lens that came with my F65 will work as a 42-120 lens on a Nikon DSLR. As a corollary, the 18-55 kit lens with the D40 does the same work as the 28-80 for the film camera.

Sunday, August 2, 2009

CSS : dot (.) vs hash (#)

. -> class selector
# -> id selector

so
.bregma { width:10cm; } -> <div class="bregma">
#lambda {widh: 5cm;} -> <div id="lambda">


PS. The # symbol is called an octothorpe (Thanks to Vicki for catching the spelling mistake)