Wednesday, 31 December 2008

Welcoming the Nikon D300

I finally part-exchanged my D80 for a D300. It was a pleasure to just hold the new camera. Same solid feel as the F100. I recall how disappointed I was when I took the D80 out of box, and saw its all plastic lightweight body.

Saturday, 13 December 2008

First shots Nikkor 50mm AF-S G f/1.4

I got the new 50mm AF-S f/1.4 Nikkor lens this week. I have not had the time to really use it properly, but did manage to take few test shots:

My first impressions are:
  • Build quality is hard to judge; it is all plastic externally. Similar finish as that of the 60mm AF-S Micro Nikkor, but the Micro Nikkor feels like better quality, perhaps because it is heavier.
  • The AF isn't very fast, slower than I expected. The Micro Nikkor focuses faster. However, this lens is brighter, which means less hunting in low light. My 50mm f/1.8 AF Nikkor focuses faster than this lens.
  • I have mostly been shooting at F/1.4, under low light conditions. This lens is definitely more suited to night photography than the Zeiss 50mm f/1.4, which is very bad at handling point sources of light. Coma correction seems better than the Zeiss, but I can still see coma, even in the DX crop images. So much for Nikon's claim that this lens is very well corrected for sagittal coma. It may be better corrected than the older version, but I doubt it will reach the same standards as that of the Leica Summilux-M 50mm f/1.4 ASPH.
  • Strong sources of light cause ghosting, due to internal reflection. These can appear as ugly purple blobs of light, floating randomly across the image. Seems to be more of an issue when the background is very dark.
  • Lens does suffer from color fringing (chromatic aberration) at maximum aperture, but I suspect this can be corrected to a large degree in software.
  • Overall, the lens seems usable at maximum aperture under low light conditions, which is good news. However, care is needed to avoid ghosting when strong light sources are present.
Unfortunately, I do not have the older AF-D version to compare this lens with. I do have the 50mm f/1.8 AF Nikkor (non D version), and hope to do some comparative tests later.

Saturday, 25 October 2008

AFS Micro Nikkor 60mm f/2.8

I rented a Nikkor 60mm f/2.8 over a weekend so that I could compare its performance with my Nikkor 50mm f/1.8. The results can be found here.

dibyendumajumdar's Nikkor 60mm f/2.8 AFS versus 50mm f/1.8 photosetdibyendumajumdar's Nikkor 60mm f/2.8 AFS versus 50mm f/1.8 photoset

I wanted to find out whether the 60mm could be used as a replacement for a standard 50mm lens for general photography. The answer seems to be a 'yes', if you are happy to give up 2 stops of speed. My tests are not scientific, but they seem to indicate that the micro nikkor has the edge over the 50mm lens at comparable aperture stops. What do you think?

I also hope to try out the Sigma 70mm f/2.8, which according to some review sites, is the sharpest lens in the Sigma line-up.

Tuesday, 21 October 2008

My dream lens

My dream lens is one that is reasonably fast (f/2 at least), has exemplary sharpness right from the maximum aperture, is affordable, and has a camera that delivers great image quality up to ISO 1600. Not much to ask for but alas, there is not such a lens in the market.

Only Leica lenses seem designed to work well right from the maximum aperture. An illustration of this can be found at this comparison of the Nikon Millennium S3's 50/1.4 versus Summilux ASPH 50/1.4. Okay, this is not a fair test, as the Nikkor is a remake of a very old design, but I am pretty sure that the current SLR standard lenses from most brands, including Nikon, do not match the Leica's performance at f/1.4.

But the Leica is way too expensive. And doesn't have a camera that can exploit the quality of the lens.

Inconsistent exposure with Nikon D80

Recently I shot some test pictures with my Nikon D80 and a Nikkor 50mm f/1.8 lens. To my surprise, there appeared to be an inconsistency in exposure. I shot exactly the same scene at f/1.8 and at f/2.8. The exposure at f/1.8 seemed perfect, but the shots at f/2.8 were over exposed.

The test photographs can be seen at my Flickr Photostream.

Ken Rockwell discusses the D80's propensity for over exposure. Searching on Google reveals many others have faced similar problems.

Tuesday, 7 October 2008

High anticipated 50mm f/1.4 Nikon Lens

The recently announced 50mm f/1.4 AFS Nikkor was much anticipated for several reasons:
  • The existing 50mm Nikkor will not autofocus with the newer range for low-budget Nikon SLRs.
  • The 50mm f/1.4 design hasn't changed in two decades, and as with most lenses that were designed more than 20 years ago, the design was looking slightly outdated.
Still, I had almost given up hope that Nikon would introduce such a lens. Nikon's policy in recent years has been to focus on Zoom lenses. No doubt their lens sales indicate this is where the market demand is. What many people who criticize Nikon for not releasing exotic primes don't realize is that for many years now, Nikon's lens production seems driven by "what sells". During the film era, Nikon had a range of "prestige" lenses, which looked great on paper, but few could afford to buy. Ever since Nikon lost ground to Canon in the professional market in the 1990s, and its profitability plunged, Nikon changed its strategy. No more indulgences, all lenses must sell (and presumably make a profit). If you are a lens designer working at Nikon, it must be very hard to get any exotic lens design past the marketing guys.

How many people buy the 50mm lens anymore? It would be interesting to see some statistics. I am sure that the majority of the 5 million Nikkors sold in the last year were mostly zoom (kit) lenses.

I want a good 50mm lens that performs well under low light conditions. It is no good having an f/1.4 lens that performs well at f/5.6 but poorly at f/1.4. I am not talking of sharpness alone. At f/1.4, most lenses handle point sources of light very badly due to coma aberration. I haven't tested the old 50mm Nikkor AF-D, but I know that even the Zeiss ZF 50mm f/1.4 doesn't handle coma very well at f/1.4.

I remember that one of Leica's main selling points was that its lenses were designed to perform well at their maximum apertures. I still remember that in a brochure they had provided comparisons of a night scene shot with the Summilux-R 50mm f/1.4 and an unspecified competitor lens.

The introduction of the Sigma 50mm f/1.4 lens was interesting because of the special attention Sigma had paid to the correction of coma aberration. Sigma claim that even at maximum aperture, this lens is very well corrected. Surprisingly, the two tests published so far (DPreview and Photozone), do not test this aspect of the performance. This goes to show that most testers do not test a lens for its primary design goals, they just apply a simplistic yard stick to judge a lens, regardless of the especial characteristics of each lens.

With the new AFS Nikkor f/1.4, Nikon are also claiming good correction of coma, but it is not clear whether this is at maximum aperture. Surprisingly, Nikon have not used an aspherical lens element in the design (they used an aspherical lens element in the famous 58mm f/1.2 Noct-Nikkor and in the 28mm f/1.4 Nikkor to correct coma). I think this has something to do with preserving a good bokeh. This is probably the same reason why the 85mm f/1.4 Nikkor doesn't have an aspherical lens element. Cost probably is no longer an issue, as aspherical lens manufacturing has improved considerably, but I could be wrong.

The lens is much smaller in size compared to the Sigma. It remains to be seen whether its maximum aperture performance is better than the Sigma. I would expect the bokeh to be better, but coma correction to be worse.

Tuesday, 30 September 2008

Why most lens tests are flawed

Several lens test sites have sprouted in recent years. The test results published by these sites are taken seriously by many users, therefore, it is important to understand what value we can attach to these tests.

Firstly, the lenses are tested at a particular focal plane, i.e., the distance between the lens and the test object is fixed. As we all know, in the real world, a lens is focused anywhere between its closest focusing distance and infinity. To test a lens at a single focal plane and then to extrapolate from this an overall judgment of the lens performance is flawed in my opinion.

Secondly, certain lenses are designed for specific types of photography. Such as macro lenses for macro photography, short telephoto lenses for portrait photography, long telephoto for sports/wildlife etc. To test a lens outside of its usage context seems pretty pointless. One has to understand what purpose the lens is to serve, and devise tests accordingly.

I suggest that anyone interested in lens design should read the articles published under Nikkor Thousand and One Nights. Each article describes the goals that were aimed for during the design of a particular lens. This gives you an appreciation of why one-size-fits-all type of testing is so inadequate.

In my experience the real life performance of a lens cannot be judged by any of the tests published online. It is best to try out a lens yourself, perhaps rent it from a rental shop before buying it.

The Multi-CAM 1000 sensor

This was first posted in May 2008

There does not seem to be much information available on the D80's Multi-Cam 1000 sensor. I have had a few pictures that are out of focus, even though the focus point is where it should be. At first I blamed the Sigma 18-50mm lens, but now I am beginning to think, it is the AF sensor.

The first issue is that the focus points that are to the left and right of the central area can only detect horizontal lines. I tested this, and found that they simply don't detect vertical lines.

Secondly, the focus central focus area itself is slightly bigger than the bracket displayed on screen. If multiple objects appear inside the area covered, then the camera can end up focusing on the wrong thing.

An out of focus picture is a real disappointment as it is not always evident until you look at the picture at 100% magnification. By then it is too late to fix it. Hopefully as I learn more about how the D80 focuses, I will be able to get more pictures in perfect focus.

I am surprised that none of the D80 reviews really look at its auto-focusing abilities in depth.

Update: I asked Nikon Support about the layout of the AF sensors. The answer I got was this:

The centre AF area is a cross type area. The 2 AF areas above and below the centre area are horizontal AF sensors and all the rest are vertical AF sensors.

This means that the 2 sensors above and below the central sensor can only detect vertical lines, and the rest of the sensors, apart from the central one, can only detect horizontal lines. I have to see if I use this knowledge to get perfect focus each time.

Sigma 18-50mm F2.8 EX DC HSM Macro review

This was first posted in May 2008

I bought this lens a few days ago for my new D80. Here are some observations after testing the lens both indoors and outdoors.

It is soft at F2.8, even at the centre, especially at the 50mm setting. At F2.8, performance is better at the wider focal lengths.

Generally, performance seems to improve quite a bit by F4, gets noticeably better by F5.6 and improves even more by F8. I have not printed any of the photographs yet - so do not know what the acceptable maximum print size would be at each aperture/focal length.

For majority of general photography, I would probably stick to apertures F4 and slower, and only use F2.8 if the alternative would be to not take a picture at all.

Build quality seems good - although there are two tiny specs right at the border of the front lens - so small that they are insignificant, but I was not expecting a brand new lens to have this. It was shipped to me direct from Sigma UK - I was surprised at how poorly it had been packed for shipment.

Focusing is silent. Focusing speed is okay for my purposes. There is no manual override in AF mode - despite the fact that this lens uses an HSM.

A few samples taken at f/2.8 and f/8 are posted here. These show the relative performance wide open and stopped down. You will notice that at 50mm, there is a marked degradation in performance at f/2.8.

dibyendumajumdar's Sigma 18-50mm Test photosetdibyendumajumdar's Sigma 18-50mm Test photoset

It was agonizing to choose between this lens, the Tamron 17-50mm, and the Nikkor 16-85mm. I ultimately decided on the Sigma on the basis of better build quality than Tamron, and faster speed than 16-85mm Nikkor. Sadly, the fastest aperture is not as usable as I would have liked.

I think that the tests and reviews available are often misleading (especially Popular Photography review of this lens) - as they do not reflect the real performance of this lens at F2.8. The review that I would say is reasonably accurate is:

Things that I wish the Nikon D80 did differently

This was first posted in April 2008.

Here's couple of things that I wish were different with Nikon D80:
  1. It doesn't meter with non-P, and non-AF lenses. I did not realize this when I bought it. So this means that if I use my Zeiss 50mm f.1.4 lens, I have to guess what the exposure ought to be. This is pretty bad as I am no good at getting the exposure right without a light meter.
  2. There is no ability to store a favourite configuration, like I had with my F70. This was a really useful feature - as it allowed me to quickly go back to a preferred setup. Ken Rockwell suggests a workaround in his tips on using the D80.

D80: Initial Impressions

This was first posted in April 2008:

The viewfinder is small. I had read about this, but it still came as a shock to me. Before deciding on the D80, I was looking at buying D60. I am glad now that I did not, because with the D60, I would have had to manually focus my existing lenses, and given the size of the viewfinder, this would be very difficult.

Another curious thing I noticed that when I had attached my lens, initially the viewfinder appeared very dark. It seemed as if the lens was stopped down. Once I had put the battery in, and switched the camera on, the viewfinder became bright.

Update: This is documented in the manual. Apparently, the viewfinder goes dark if the battery is not inserted or if the battery charge is low. I wonder if this is because the camera needs power to keep the lens at is maximum aperture.

Twenty years with Nikon

The first Nikon I had was when I convinced my father into buying me a second-hand Nikkormat. I had to have the camera replaced because it was faulty. The replacement was a Canon A-1.

I dreamed of owning a Nikon. By a stroke of luck, someone who worked with my Dad had an old Nikon F Photomic and a 55mm f/1.2 Nikkor which was lying unused. He offered to sell it to us for what seemed to me a very good price.

I used the Nikon F for many years until it went faulty and the cost of repairing it was higher than buying a new camera. For short while I owned the F50, replaced it with an F70, and now I own an F100 as well as a D80, which I acquired early this year.

I waited to buy my first DSLR because I felt that the price/performance ratio just wasn't right. An SLR lasted you for years, and all you did was buy lenses. DSLRs become obsolete in two years, and there is enormous psychological pressure to upgrade, just like your laptop, or your PC.