D Cox

Lives in United Kingdom United Kingdom
Joined on Jan 17, 2011

Comments

Total: 41, showing: 1 – 20
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On article 10 macro photography tips for beginners (50 comments in total)
In reply to:

Charles Sidney: You seem to imply that magnification depends on sensor size. A 1:1 macro lens will give a 1mm image of a 1mm bug on any sized sensor. Magnification is defined as the ratio of image size to object size.

You would get more pixels per mm of insect on the smaller sensor if the pixels are also smaller, as they often are.

The ideal is a big sensor with a lot of very small pixels; but these are expensive.

Link | Posted on Oct 3, 2017 at 07:54 UTC
In reply to:

Androole: The only thing I'm interested here is the supposedly new Bayer Filter technology they're talking about...

Any chance we could get a tech article?

There is in fact no point in trying to make a camera (as opposed to an eye for a robot) work like the human eye.

The purpose of a camera is not to see, but to copy the incoming data so that it can be offered to the person viewing the picture. What they should be imitating is a window or a mirror, not an eye.

Stick a camera on an outside wall next to a window. Stick a big monitor on the inside of the wall so it is side by side with the window. If the camera and monitor are perfect, they should appear exactly the same. We are a long way from that.

Link | Posted on Sep 13, 2017 at 17:14 UTC
In reply to:

D Cox: The naming seems rather silly. All colour photography (at least, since 1930) is Trichromatic. If the camera was tetrachromatic or hexachromatic, then it would be interesting.

And "achromatic" means monochrome, as in the Leica monochrome models. This device seems to a normal three-colour sensor.

The word "achromatic" came up somewhere in the guff for the new sensor. But you are right -- it seems they do offer a monochrome sensor too.

Still, trying to use Trichromatic as a product name is foolish. They may as well call it "Photographic".

Link | Posted on Sep 13, 2017 at 17:07 UTC

The naming seems rather silly. All colour photography (at least, since 1930) is Trichromatic. If the camera was tetrachromatic or hexachromatic, then it would be interesting.

And "achromatic" means monochrome, as in the Leica monochrome models. This device seems to a normal three-colour sensor.

Link | Posted on Sep 13, 2017 at 15:44 UTC as 53rd comment | 3 replies
In reply to:

KevinG: Wow!! I'm all in favor of evolving tech and image quality and have spent many $$ on equipment since 1999 but 50 grand is just stratospheric. I sure hope whoever buys this can make some money with it.

Kevin in CT

It would be much cheaper to use large format film.

Link | Posted on Sep 13, 2017 at 15:41 UTC
In reply to:

Androole: The only thing I'm interested here is the supposedly new Bayer Filter technology they're talking about...

Any chance we could get a tech article?

They claim it is more like the human retina. The medium and long wavelength cones in the eye have a wider pass band than the usual Bayer filters, with a great deal of overlap. So presumably this sensor is fitted with wider bandwidth filters than usual, rather than narrower as Conurus suggests.

Narrower band filters tend to give higher saturation, but less stable colour mixtures, with more problems with metamerism failure. Kodak used to use this effect to produce a range of more and less saturated films.

Link | Posted on Sep 13, 2017 at 15:38 UTC
In reply to:

Mike Davis: What short memories we have. Reversal processing is as old as the hills. My hat's off to anyone who goes to the effort of perfecting this on their own, especially these days, but for anyone less energetic, you can send your unprocessed B&W negatives to http://www.dr5.com/blackandwhiteslide/dr5chrome.html. (I'm not affiliated.)

Yes, I used to reversal process B&W film for making lecture slides about 30 years ago. It's easy enough -- simpler than E6 colour processing.

Link | Posted on Aug 30, 2017 at 19:14 UTC
In reply to:

Ed Ingold: The ES-2 is just what the doctor ordered. I've been using an ES-1 with a 55/2.8 Micro-Nikkor and a Sony A7ii or A7Rii (42 MP) camera to copy up to 5 rolls per hour, with cleaning and sorting. The ES-2 has an adapter for film strips, which were nearly impossible with the ES-1 (I used an FH-2 adapter from an LS-4000).

It's easy to remove dust with a conductive brush (graphene) and a strong cross light (high intensity or LED). The results are grain-sharp, even with the 24 MP Sony A7ii.

Color negatives are always difficult to achieve good color balance, even with a dedicated scanner. The simplest way to remove the orange mask is with Photoshop Limits (ctl-L), optimizing each channel manually or automatically, then inverting (ctl-I).

Also try Photoshop Curves --> Auto for removing the orange mask.

Link | Posted on Aug 26, 2017 at 18:45 UTC
On article Confirmed: Bowens is going out of business (47 comments in total)
In reply to:

RoelHendrickx: Here is a simple equation.
With ISO performance of sensors improving, more and more photographers prefer to work with naturally available light, whenever at all possible.
(I know I am one of those, and I don't even use stupidly high ISO values. I do recognize that studio lighting or competently used flash can bring something special to images, but I do also prefer, generally, the look of natural light, when appropriate, with a few reflectors.)
In any case, companies specializing in lighting equipment were bound to suffer.
Tripod manufacturers probably also feel the heat.

I don't understand why you need a 6 stop ND. What did you use when shooting with film ? ISO 100 digital is no different from ISO/ASA 100 film.
Is there no power control on those flashes ?
Or did you shoot everything at f/45 ?

Link | Posted on Jul 21, 2017 at 19:05 UTC
In reply to:

Abdouh19: Sony took 7 years from NEX to A9 ... i dont see them succeed in mirrorless market for two major raisons
1) if they create a new mount that means zero lenses , and if they go with the F-mount , the camera will look like a brick ( pentax k01 for ex )
2) sony isnt selling their best sensors anymore

The Sigma sd cameras don't look like bricks, but they are big cameras and in practice you are limited to Sigma lenses. Only M42 lenses can be adapted properly, and these are all very old now.

So the biggest advantage to the user of the mirrorless format is absent. But then, Sigma want to sell lenses, not cameras, so they don't want users adapting other lenses.

Link | Posted on Jul 12, 2017 at 17:55 UTC
In reply to:

milkod2001: What about Nikon F-mount? Is there any chance for Nikon's FF mirrorless with native F mount? Is it technically possible?

I think it is likely that within two years, Nikon F lenses will be working as well on Sony cameras as Canon lenses do now -- that is, pretty well. So the competition for bodies to use with Nikon lenses will be stronger than it is now.

I can see a possible future where Nikon and Canon are mainly lens companies, like Sigma, with rather small sales of camera bodies.

Link | Posted on Jul 12, 2017 at 17:51 UTC
On article Sigma SD Quattro H Review (643 comments in total)

I thought this was a very fair review. It should give anyone an idea of whether they would find the camera useful.

Link | Posted on May 31, 2017 at 17:23 UTC as 140th comment
On article Sigma SD Quattro H Review (643 comments in total)
In reply to:

41mm: I love this low iso beast!
Thanks for the review to dpreview! The Silent Running of a DNG APS-H camera which creators think differently.
No high iso, no fast af, but best image quality at 100 and Monochrom like a Leica.
Thats all what i need.
Time will tell and we will see.

The sdQH is particularly good for studio still life work, as well as landscape.

I bought it primarily for digitizing 35mm B&W negatives, and it has been working very well indeed for that task. The DNG file option was essential for this job, to handle thousands of files in large batches.

Yes, Sony's A7r2 is a more generally useful camera, but it does cost more than twice as much.

In colour, the results are in my opinion very pleasing. Occasionally, yellow flowers need a touch of hue adjustment with ACR's HSV sliders, but this is hardly a big problem.

Shooting in X3F and processing first in SPP does give you more adjustment options, but the DNGs are pretty good.

Link | Posted on May 31, 2017 at 17:11 UTC
On article Sigma SD Quattro H Review (643 comments in total)
In reply to:

JackM: All the DNG/ACR shots look decidedly "un-Foveon" and soft to me. Try again with Sigma Photo Pro and X3F files?

Most users dial the sharpening down in SPP too.

Link | Posted on May 31, 2017 at 17:01 UTC
On article Sigma SD Quattro H Review (643 comments in total)
In reply to:

Ben Herrmann: OK - so this now poses the question, "With all of the advances made in camera technology over the past decade (save perhaps with the Foveon sensor), how in the hell is it that Sigma is still producing ancient looking (and feeling) cameras that are way behind the power curve with regards to AF speed, high ISO cleanliness, DR, and so much more?" I mean, c'mon mannnnnn.....

Sure the Foveon colors are really nice (rich), but with all of the other issues that seem ongoing with Sigma camera releases, this means that very few will embrace their line of cameras. Now lenses are an entirely different matter.

I think you need to see and handle this camera in the flesh to judge its look and feel.
It is admittedly heavy, but very comfortable to hold and use. And the styling is well thought out, with very good detailing.

I see it as a replacement for a 6x9 film camera such as the Mamiya Press; and its design and ergonomics are very much better than that.

Link | Posted on May 31, 2017 at 17:00 UTC
On article Sigma SD Quattro H Review (643 comments in total)
In reply to:

T3: Sigma should really make a short-flange E-mount version! If they did that, it would probably outsell this SA-mount version. And it would go great with the Sigma FF lenses that they've said they are planning on making for Sony E-mount:

http://www.sonyalpharumors.com/sigma-ceo-confirms-will-launch-full-frame-e-mount-lenses/

Sigma primarily want to sell lenses, not cameras. So it is of no advantage to them to offer other mounts or sell sensors.

They make little or no profit on the camera bodies. The profit comes when the user has bought a couple of Sigma lenses.

Link | Posted on May 31, 2017 at 16:56 UTC
On article Sigma SD Quattro H Review (643 comments in total)
In reply to:

Mfritter: I used to shoot Merrills. I discovered that one could get very nice higher ISO (6500) monochromes using SPP to eliminate the red and green channels. The blue channel was basically noise free. Anything on the Foveon's ability to do this?

Yes, it works much the same as from the Merrill sensors. You could certainly use the camera for B&W available-light work, like the classic French shots in bars and cafes.

Link | Posted on May 31, 2017 at 16:52 UTC

I typed in the names of a couple of well known photographers, but nothing came up.

Nor did there seem to be any long list to browse through (three or four names were offered).

So, not yet ready, I think.

Link | Posted on May 30, 2017 at 14:48 UTC as 7th comment
In reply to:

Terry M: Wow! I was a newsstand buyer of Pop Photo for YEARS. After discovering back issues in my local library there was no question in my mind they were the preeminent source on photography and photographic equipment. Everything I bought was run by their reviews first. Of course that was a while back. Now I do most of my photography-related reading online, whether it's standalone photo websites or web-based corollaries to photography magazines. On that count, PopPhoto.com is a pretty awful site. Shutterbug's done a lot better job with their site, and of course, the British magazines are still out there. So long, PopPhoto.

The British Journal of Photography has done a very good job of re-inventing itself for the digital age. It is quite expensive, production standards are very high, and there is a strong web presence.

But it is about images and ideas rather than equipment. Equipment reviews are just a few pages at the back of the magazine.

Link | Posted on Mar 8, 2017 at 09:33 UTC
In reply to:

Betico: Modern Photography was the first to go, purchased by Popular Photography. I still remember their annual top cameras issue.

I think Modern was the better magazine. I learned a lot from those guys.

Link | Posted on Mar 8, 2017 at 09:25 UTC
Total: 41, showing: 1 – 20
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