Digital Camera Buyer's Guide Introduction - Comments

[Andre]

I For example, my luminar lenses are 50 years old and I'm willing to bet they will outperform any contemporary macro lens, period- not just the optical quality but also the fact that they can be used on a 4" x 5" view camera (and possibly an 8 x 10).

That's quite a statement. Would that imply that 50 years of innovations like aspherical, low dispersion elements and diffractive optics not could prevent that lens making deteriorated?

 

[Andy Resnick]

That's quite a statement. Would that imply that 50 years of innovations like aspherical, low dispersion elements and diffractive optics not could prevent that lens making deteriorated?

I stand by it. For whatever reason, Zeiss stopped making those lenses in the 1970's- none of those technologies (except possibly aspherical surfaces) which I agree could improve the optical performance of those lenses were ever incorporated. The fact that each lens has only three elements makes the optical performance even more astounding.

I'd be happy to put my claim to the test- all we need is a 'standard object' that we can all photograph using whatever tools we wish. My only constraint is that I need to work indoors. Normally I would suggest a coin or piece of newspaper, but given the international participation in this forum, it's not obvious what the best choice would be.

 

[Andre]

Sure you can compare with what we can and I would love to see results of that lens but it's not a game/match. I know that my 7D/100mm macro is not the best in the world, Borek beats it already with the 100mm L-version, but with a 5D mk2 body, results would even be better which would be topped by the A900, since the resolution is a function of both lens resolution and sensor resolution.

But we can compare pix maybe of a yardstick, or matches or playing cards, or a certain common brand of batteries.

 

[Borek]

Andre and I can take a picture of Canon's lens cap

 

[turbo]

Andre and I can take a picture of Canon's lens cap

From the inside? Your 100mm macros should deliver equivalent quality, I would think.

 

[Andre]

yes here is mine

[PLAIN]http://dl.dropbox.com/u/22026080/lenscap.jpg

Anyway, I would also be interested to see results compared to the Canon MP-E 65mm

 

[Andy Resnick]

Here's some preliminary results using two resolution targets. The first is from Edmund optics and is a chrome on glass variable bar target:

[PLAIN]http://img191.imageshack.us/img191/9345/targeto.jpg

and the second for higher-magnifications is a Richardson Gen III test slide:

[PLAIN]http://img97.imageshack.us/img97/9681/targetda.jpg

The images below are taken from that small region in the dead center.

There's a few things to keep in mind- first, although the targets are specified in terms of a length (for example, 5 line pairs per mm), the proper way to compare lenses is by the angular resolution: line pairs per radian. I didn't measure the object distance so I can't convert the units properly.

Second, the pixelated nature of the CCD results in imaging artifacts, especially aliasing:

[PLAIN]http://img638.imageshack.us/img638/7117/aliasing.jpg

In this case, it shows the effect of angular misalignment between the bars and the pixels. A related issue is the Bayer filter, but from the point spread images I took earlier, that issue may not be a significant one.

Lastly, for whatever reason I set the camera to 6 MP instead of the full resolution. This is probably a fatal flaw. In any case... From top to bottom are images from the 100mm, 63mm, and 25mm at full aperture, at the two useful extremes of reproduction ratio. For the 100mm, this is 1x and 1.78x (45 lp/mm and 75 lp/mm), while the 63mm images are at 2.5x and 4.5x (105 lp/mm and 190 lp/mm) and the 25 mm is 10.5x and 28.5x- the largest bars are 2 microns wide (4 microns per light/dark pair):

[PLAIN]http://img204.imageshack.us/img204/3050/topdi.jpg

What I should probably do is re-take these at full resolution...

 

[Andre]

Impressive Andy and yes, resolution is a function of lens resolution and sensor resolution. But maybe this should go in another thread?

 

[Topher925]

I ended up pulling the trigger on a Nikon d5100 w/kit lens and 55-300 DX VR lens last night. Amazon was having a killer deal where I got the stuff above and a camera bag for a little over $900 shipped. While I was leaning more towards getting the K-5, it just seemed like too good of a deal to pass up.

 

[Borek]

Can we find or prepare some kind of test that each one of us could print to take pictures of?

 

[turbo]

How available are bicycle-brand playing cards in Europe? When the cards are new, they are very flat, and the printing quality on the backs is generally excellent and consistent to foil cheats.

 

[Andy Resnick]

I ended up pulling the trigger on a Nikon d5100 w/kit lens and 55-300 DX VR lens last night. Amazon was having a killer deal where I got the stuff above and a camera bag for a little over $900 shipped. While I was leaning more towards getting the K-5, it just seemed like too good of a deal to pass up.

Excellent- I think you will be very happy with your decision!

 

[Andy Resnick]

Impressive Andy and yes, resolution is a function of lens resolution and sensor resolution. But maybe this should go in another thread?

Probably- I think some sort of "shoot out at the PF corral" thread makes sense for this.

Can we find or prepare some kind of test that each one of us could print to take pictures of?

All we need is a 'standard object' (or a few objects of different sizes if we want to go beyond macro shooting)

How available are bicycle-brand playing cards in Europe? When the cards are new, they are very flat, and the printing quality on the backs is generally excellent and consistent to foil cheats.

This is a good suggestion- there does not appear to be very much fine detail, but it's probably good enough. How about the hologram sticker on credit/debit cards? Just a suggestion for something commonly available...

Edit: I think it's worth saying that this isn't a "mine's bigger than yours" competition. There's a lot of optics knowledge that goes into setting up and quantitatively evaluating images, and this should be treated as an educational resource.

 

[turbo]

No, Andy, there is not a lot of really fine detail on the card backs, but they could make pretty decent long-distance targets. Just trying to think of something cheap and consistent. I long ago abandoned my wall-sized resolution chart (Edmunds, I think). When I was considering buying a zoom lens for my Olympus kit, I borrowed several from friends, including one who owns a camera shop, and used that chart to put the lenses through their paces. I gave up on the zoom idea right after developing and printing that film.

It was with a bit of trepidation that I jumped in with a Canon 30D and 100-400mm L, because of the expense, but I have a friend on another forum who shoots wildlife/birds from a blind with the 100-400, and the quality is scary-good. Zooms have come a LONG way in the last ~40 years.

 

[Andre]

I ended up pulling the trigger on a Nikon d5100 w/kit lens and 55-300 DX VR lens last night. Amazon was having a killer deal where I got the stuff above and a camera bag for a little over $900 shipped. While I was leaning more towards getting the K-5, it just seemed like too good of a deal to pass up.

Congrats. I hope you enjoy it. Actually a few years ago I had a similar experience, I was charmed by the multigadget Sony A350 and I had already ordered it (tentatively), I thought that the Canon 450D, the other one of the shortlist, was way too simple and a bit expensive in comparison, then I saw the test results and I never looked at the Sony again.

But that was just a moment in time and Nikon really had no competative model at that time that made it to my shortlist.

 

[Andy Resnick]

No, Andy, there is not a lot of really fine detail on the card backs, but they could make pretty decent long-distance targets. Just trying to think of something cheap and consistent. <snip>

I was thinking more and realized that there doesn't have to be fine detail, as long as the pattern edges are sharp- it's still possible to extract the modulation transfer function.

Cards sound good to me- consider that a second. How about the overseas folks?

 

[turbo]

I was thinking more and realized that there doesn't have to be fine detail, as long as the pattern edges are sharp- it's still possible to extract the modulation transfer function.

Cards sound good to me- consider that a second. How about the overseas folks?

Well, I guess a pack of cards isn't that much of an investment, so we could spend a few bucks to split a deck and send one or two cards to others who want to use those as test targets.

I'll send you some money to buy a deck of cards and pay for postage if you want to supply targets to Andre, Borek, and others. I can't get out too much due to my sensitivity to fragrance chemicals, so if you can handle the logistics, I'll pay the cost. It might be better to use cards within a single pack, to keep printing-variables as even as possible.

 

[Andy Resnick]

Well, I guess a pack of cards isn't that much of an investment, so we could spend a few bucks to split a deck and send one or two cards to others who want to use those as test targets.

I'll send you some money to buy a deck of cards and pay for postage if you want to supply targets to Andre, Borek, and others. I can't get out too much due to my sensitivity to fragrance chemicals, so if you can handle the logistics, I'll pay the cost. It might be better to use cards within a single pack, to keep printing-variables as even as possible.

I'm not sure I want to open "Andy Resnick's Playing Card Emporium" just yet :) Interested people can buy them directly online, anyways:

http://www.playingcardsandmore.com/bicycleplayingcards.aspx?gclid=CISzw92Py6sCFcjc4AodPgS63w

As it happens, I'm teaching the Advanced Optics Lab class next semester, and I've been trying to come up with a few labs to replace the (ahem) useless ones. For example, I'm thinking about a lab that centers on this:

http://www.skymall.com/shopping/detail.htm?pid=203769555&c=10323

and a "imaging performance" lab could also be a nice addition. I've come up with a preliminary procedure that I can debut here and see if it's worthwhile to fully develop for the course.

So, for anyone interested in quantitatively measuring the imaging properties of a lens, I'll work to get a rough draft started in a new thread. Details to follow, but all you need to start is a greyscale photo containing a light-to-dark transition.

 

[Topher925]

I know most people here shoot Canikon, but I can't say enough about how much I love my new Pentax. I finally got some time this morning to really try it out and while I'm still learning, I think the results are fantastic. Can't wait to get some nice lenses for it.

 

[Andy Resnick]

Excellent- hope you are having fun!

 

[Topher925]

Zooms or Primes

What type of lenses do you experienced photographers prefer to shoot with most of the time. I currently only own two zoom lenses (one being the kit lens) and I'm thinking about either getting 1 or 2 primes or a nice large aperture zoom lens. I mostly care about image quality right now so I'm thinking about adding some primes to the collection but is there really that significant of a difference between a good zoom lens and a good prime?


Pic taken earlier today with the Pentax 18-55mm WR kit lens:

 

[Borek]

is there really that significant of a difference between a good zoom lens and a good prime?

In my experience - yes, primes are better.

How come you bought a Nikon and you shot with Pentax?

 

[Andre]

Yes the Pentax K-5 is a great camera, best in class for high ISO noise. But if you insist on comparing with Canikon, the available glass for Pentax is not the best. It may be harder to find what you like.

A comparison between zoom or primes is apples and oranges. Yes primes trend to be sharper because they can be simpler but there are many (expensive) zooms outperforming (cheaper) primes. But when you find yourself constantly changing primes, missing shots, whereas you could have solved the situation with a simple turn of the zoom ring, make sure you have some zooms as well.

Quality is expensive and this looks like a good one
http://www.slrgear.com/reviews/showproduct.php/product/1234/cat/46

 

[Topher925]

I ended up purchasing a Pentax 40mm f/2.8 prime lens today. I figured I'd try it out and see how I liked it since prime lenses are suppose to be Pentax's specialty.

How come you bought a Nikon and you shot with Pentax?

I ended up canceling/returning the order for the Nikon. After trying it out again at the store it felt too much like a soccer mom's camera. To add to that, nice glass from Nikon is very expensive. Sure, the lens selection for Nikon is much greater but it seemed that I needed to spend nearly twice as much to get decent basic lenses.

The K-5 is a VERY nice feeling camera. Compact, sturdy, great ergonomics, and the weather resistance is a big plus too.

But when you find yourself constantly changing primes, missing shots, whereas you could have solved the situation with a simple turn of the zoom ring, make sure you have some zooms as well.

Right now I have the kit 18-55mm and DA 55-300mm lenses so I've got just about all the focal lengths covered. The kit lens will get replaced eventually (performs great for such a cheap lens though) and I really like the 55-300mm. I'll probably get the Tamron 17-50mm f2.8 somewhere down the road to replace the kit lens. I'm still shooting a lot and not quite sure what focal lengths I want in a walk around lens.

 

[Andy Resnick]

What type of lenses do you experienced photographers prefer to shoot with most of the time. I currently only own two zoom lenses (one being the kit lens) and I'm thinking about either getting 1 or 2 primes or a nice large aperture zoom lens. I mostly care about image quality right now so I'm thinking about adding some primes to the collection but is there really that significant of a difference between a good zoom lens and a good prime?

Outdoors, I shoot a 15mm f/3.5(Nikon), 85 mm f/1.4 (Zeiss) and 400mm f/2.8 (Nikon). When I go wandering around, I'll take either the 15mm or 85mm (rarely both). I prefer primes for aesthetic reasons- it forces me to think more. For the macro/micro shots, I use more specialized equipment- I have a favorite lens just for reflected DIC imaging, a (different) favorite lens for transmitted DIC, another for phase contrast, another one or two for macro, others for darkfield, etc.

There are good quality zoom lenses- some have a surprisingly large range of focal length. For me, I went to the extremes beyond zoom coverage- although there are 12-24mm zooms, they don't have an aperture ring and they have more distortion than the 15mm. I was considering the Voightlander 12mm, but I'd have trouble using that lens with my camera.

It's important to realize that good lenses are designed to image a few things really well, so you should think about what you want to photograph- landscapes? wild animals? people? buildings? studio work? night/dim light? Each of those subjects has different requirements in terms of focal length and aperture. Again, there are some good zooms that can cover a large range of subjects.

 

[Topher925]

Well I got my new prime the other day and so far I really like it. Not only is the lens extremely well made but the IQ is incredible. I won't be able to put it through its paces until later this weekend but so far I'm very happy with it. I'm really tempted to get the DA* 55mm f1.4 but I guess I should pace myself and not blow my entire bank account on lenses.

 

[Borek]

If you want to be able to compare lenses you should post uncropped 1:1 part of the image. At 640 pix even pictures taken with cheap, idiot cameras look perfect.

And I think we should move the discussion to photography thread, or start lenses thread.

 

[Andre]

Especially for Turbo, who once expressed the wish for an affordable full frame Canon

http://www.dpreview.com/products/canon/slrs/canon_eos6d

 

[turbo]

Especially for Turbo, who once expressed the wish for an affordable full frame Canon

http://www.dpreview.com/products/canon/slrs/canon_eos6d

Thanks, Pooh. I'd have to sell off some other gear in order to justify that camera, but it looks like a really nice package.

 

[Ara Maxene]

I'm not interested with DSLR coz I find it complicated to use, lol. I have a Samsung Galaxy Camara. It works like a semi-smart phone too. The only difference is that you cannot make a call but you can send and receive sms. You can immediately post the photos to facebook and other social media channels. It is so easy to use.