Register to reply

PF Photography Thread

by _Mayday_
Tags: photography
Share this thread:
Borek
#1117
Jun27-11, 01:00 PM
Admin
Borek's Avatar
P: 23,369


Sorry, no strawberries.

(For newcomers: larkspur was a user at PF, active up to about two years ago. Her pictures were always great, one of them was a picture of strawberries in the rain - in a way similar to what I took today. Unfortunately, her pictures are no longer hosted at old urls.)
fuzzyfelt
#1118
Jun27-11, 01:26 PM
PF Gold
fuzzyfelt's Avatar
P: 742
No apologies necessary (IMO), it is wonderful without strawberries!
Andre
#1119
Jun28-11, 08:20 AM
PF Gold
Andre's Avatar
P: 5,458
Quote Quote by Borek View Post
Please let us know how it works. Seems cheap.
The card just arrived, it's in the camera. Burst in RAW+JPG roughly on par with the sandisk card, that is, after the first 6-8 shots the rate goes down to maybe 4 frames per second. Movie mode seems fine too.
Andre
#1120
Jun29-11, 07:52 AM
PF Gold
Andre's Avatar
P: 5,458
Update

I downloaded the evaluation version of flash memory toolkit and did a read test with both cards (write test blocked). Both claim to be 400x with reading (up to) 60MB/s for scandisk and 90MB/s for the Transcend.

On my computer though, it was 16.7MB/s average for the old Sandisk and 18.8MB/s for the new Transcend. Not what you expect but it compares better

Edit:

Of course you can test write speed too just by writing. So I formatted both cards and then wrote a 1.05 GB big folder containing 45 pix to each.

A modern duracell 8MB USB memory stick required 3:19 minutes for that or 5.3 MB/s, the scandisk was ready in 1:38 minutes (10.7 MB/s) and surprisingly the Transcend 1:06 minutes (15.9 MB/s)

Verdict: it's a keeper, the scandisk is now permanent reserve.
Borek
#1121
Jun29-11, 10:16 AM
Admin
Borek's Avatar
P: 23,369
Thanks for the update. I see them here as well, unfortunately, I won't be able to buy one before leaving (it won't arrive in time).

So far your tests confirmed speed, let's hope it will be also reliable. I am always afraid of things substantially cheaper than equivalents.
Andre
#1122
Jun29-11, 10:27 AM
PF Gold
Andre's Avatar
P: 5,458
Quote Quote by Borek View Post
Thanks for the update. I see them here as well, unfortunately, I won't be able to buy one before leaving (it won't arrive in time).

So far your tests confirmed speed, let's hope it will be also reliable. I am always afraid of things substantially cheaper than equivalents.
Yes I know the feeling, but it is just a feeling. Maybe, if you aren't a famous brand, you'd have to compete both with quality and low budget prices. I've seen a lot about that in the jeans branch.

So I am not pessimistic but I'll download the pix frequently.
Andre
#1123
Jul25-11, 03:34 AM
PF Gold
Andre's Avatar
P: 5,458
Quote Quote by Andre View Post
Thanks Turbo

Here is a small selection. I just happened to shoot them this evening, unaware of this thread. The dog loved to play model and I got her all over me after the dash, every time, when I was laying there on the ground.





We won!

http://www.dpreview.com/challenges/Entry.aspx?ID=477595
Andy Resnick
#1124
Jul29-11, 08:03 AM
Sci Advisor
P: 5,510
I had to get a 'new' image processing program (GIMP, while possibly the *worst* name ever, is available free at http://www.gimp.org/) in order to submit a paper to PLoS, and it does some things that ImageJ does not- one thing in particular is a 'perspective tool'.

Recall that, given a fixed 35mm image format, lenses with a focal length equal to 50 mm provide images with perspective matching human vision, while lenses with shorter focal lengths provide exaggerated perspective and lenses longer than 50mm reduce the perspective.

Here's an example: I used a 15mm lens to take a photo of Cleveland's tallest building, the Key Tower with 57 stories and almost 1000 feet tall:



The short focal length lets me get the whole building in the frame, but because of the increased perspective distortion, the building appears to recede rapidly into the distance, much more that it appears when looking at the building by eye. Of course, you can't fit the whole building on your retina unless you stand much further away from the building than I did here, which is why I used a wide angle lens to begin with.

Using the perspective tool, I can mimic the effect of using a tilt-shift (or long focal length) lens- parallel lines remain parallel:



This image is impossible to obtain 'naturally'- in order to flatten the perspective this much by using a telephoto, I would have to stand so far back that the view would be obstructed by other buildings. Although Canon makes a 17mm tilt-shift lens (http://www.luminous-landscape.com/re...non-17ts.shtml), I'm not sure it could move enough to accommodate this building. A telecentric lens would need to have a front element 1000 feet in diameter to take this image.

An important reason I was able to perform this manipulation is that the lens has no distortion- straight lines remain straight. That's a major reason I got this particular wide angle lens (Nikkor 15mm f/3.5) instead of other wide angle lenses.

I like the result- the building looks normal and different at the same time. I'll be on the lookout for other opportunities to try this out- lighthouses could be very compelling subjects, for example. The Statue of Liberty would be *excellent* since it's so iconic, but I don't know when I'll be in the city next.
Andre
#1125
Jul29-11, 08:16 AM
PF Gold
Andre's Avatar
P: 5,458
Nice Andy, indeed a great result making lenses worth a fortune obsolete.

I also use Gimp sometimes, with a HDR plug in.

Nowadays Canon's software Digital Photo Professional (DPP) can apply lens corrections for the lens errors dedicated per lens, the peripheral illumination, chromatic abbaration, distortion and color blur.

Also, standard lens 50mm for 35mm film format (FX) yes that is the common assumption. However the focal distance of the standard lens (normal lens) is defined as equal to the diagonal size of the film or sensor format and the image diagonal of full frame FX is 43.3 mm
Andy Resnick
#1126
Jul29-11, 11:56 AM
Sci Advisor
P: 5,510
Quote Quote by Andre View Post
Nice Andy, indeed a great result making lenses worth a fortune obsolete.

I also use Gimp sometimes, with a HDR plug in.

Nowadays Canon's software Digital Photo Professional (DPP) can apply lens corrections for the lens errors dedicated per lens, the peripheral illumination, chromatic abbaration, distortion and color blur.

Also, standard lens 50mm for 35mm film format (FX) yes that is the common assumption. However the focal distance of the standard lens (normal lens) is defined as equal to the diagonal size of the film or sensor format and the image diagonal of full frame FX is 43.3 mm
Thanks- and I agree that there's nothing objectively correct about calling a 50mm lens 'normal'.. what's normal? :) I've read screeds on a few Nikon pages that go on about 55 mm lenses. The bottom line is how the printed/displayed image compares to how the naked eye views the object.
Andy Resnick
#1127
Aug1-11, 09:05 PM
Sci Advisor
P: 5,510
an alternate edit of the photo I submitted this week:



This image has been manipulated enough to disqualify it as a submission, but I like the 'discomforting' aspect of the image. I should set this as my desktop pic.. :)
khemist
#1128
Aug2-11, 02:07 AM
P: 267
Quote Quote by Andy Resnick View Post
Thanks- and I agree that there's nothing objectively correct about calling a 50mm lens 'normal'.. what's normal? :) I've read screeds on a few Nikon pages that go on about 55 mm lenses. The bottom line is how the printed/displayed image compares to how the naked eye views the object.
50mm is normal because it is almost the same magnification as your own eye. However, if you are on a crop sensor you will not see 50mm with a 50mm lens, rather you will see ~80mm.

The more you pay = the sharper your photos are. Goes for tilt shift too...
Andy Resnick
#1129
Aug3-11, 08:32 AM
Sci Advisor
P: 5,510
Speaking of tilt-shift lenses, here's another corrected image:



This building has fascinated me for years- it's a bombed-out hulk that's been abandoned for at least as long as I've lived in Cleveland, sitting in the middle of a high-priority redevelopment zone. A glorious example of urban decay.
Andy Resnick
#1130
Aug3-11, 07:21 PM
Sci Advisor
P: 5,510
Driving by the building on my way home today, I realized I didn't fully correct the above image. While I did correct for perspective (lines that are parallel in depth are not imaged as parallel lines), I did not correct for the angle between the optical axis and the wall of the building- the aspect ratio of the building is incorrect. Here's the effect of correcting for that, so that the line of sight appears perpendicular to the building:



It's apparent something's wrong- parts of the building that are closer than the main wall (the central and right-side projections) have a different magnification. I'm not sure I can fix that...
Andy Resnick
#1131
Aug4-11, 08:39 AM
Sci Advisor
P: 5,510
I worked with the above image in GIMP to produce this:



This image has been (crudely) manipulated to produce a telecentric image of the building: there is constant magnification with object distance. The foreground is now out of scale to the building (those telephone poles are not 80+ feet high...), and the wires don't line up like they should.

To produce an image like this without digital manipulation, you would need a telecentric lens about 300 feet in diameter, with a working distance of 200 feet: an f/0.6 lens the size of a football field. But then the foreground would be in proportion....
redpenguin
#1132
Aug7-11, 10:53 PM
P: 33
Long exposure.
sourlemon
#1133
Aug8-11, 08:29 PM
P: 80
^redpenguin, that's gorgeous! What did you take a picture of?
redpenguin
#1134
Aug8-11, 09:43 PM
P: 33
I actually turn all of the lights out in my house and just take a picture of my television. This particular movie was Red Cliff (which is an awesome John Woo movie if you haven't seen it). Sometimes I get lucky.. most others I don't. But I have noticed that there is a method to the madness.
Couple other examples (sorry for the size of some)..
Morgan Freeman:

Pretty Lady:

Time:

Is there a sixth sense?:


Register to reply

Related Discussions
Photography website General Discussion 10
Mirror Photography Project Introductory Physics Homework 1
Best institue in US To learn Photography Academic Guidance 5
[ Photography ] General Discussion 6