Has anyone compared this Sigma to the Nikon 35mm? Here is a comparison to the Canon 35mm and the Sigma blows it away but the Nikon is a much newer lens.
Either way, the Sigma is way sharper than the Canon:
http://learningcameras.com/reviews/7-lenses/87-sigma-35mm-f14-vs-canon-35mm-f14

Mac The knife said:
I bought a D70s off of Ebay that ended up having a stuck shutter. While emailing the seller, I found a web page detailing what a guy did to fix his, and did the same, but without the scissors. I may have got lucky, but I kept the camera, and the seller and I agreed upon a 50 dollar refund.

That repair job only works of you're hoping that the stuck shutter will unstick itself. I wouldn't invest in a possibly dud camera.

Here's the webpage,,,, http://johnbagnell.blogspot.com/2009/08/how-to-fix-d70s-or-d70-shutter.html

I bought a D70s off of Ebay that ended up having a stuck shutter. While emailing the seller, I found a web page detailing what a guy did to fix his, and did the same, but without the scissors. I may have got lucky, but I kept the camera, and the seller and I agreed upon a 50 dollar refund.

You can get a very nice D70s or D50 from Adorama used for $150-200. For more money a more current body such as a D90 or other. Having an old body repaired is way too expensive. Once a body is several years old, unless it is a pro body, repairs are almost more than what it is worth.

Find another body. Take it for free. Working $120 - $200tops

framer

Hi Bob,

Welcome to the forum.

I would pass on that one if it were me. Presuming you would get it repaired, you would end up paying quite a lot for a really old tech camera. If you are thinking of getting it converted to infra-red, then it may be worth it but it doesn't sound like that's your plan.

The test was outside so it could just be an exposure jump. I don't think they are reversed because depth of field appears to increase continuously.
Seems to be an awesome lens though for almost half the price of the Nikon 35mm f/1.4

Hi All,
I am Bob with an opportunity to buy a D60 (body only) with a known stuck shutter for about $50. I currently have an N2000 that does not work, no display in viewfinder with new batteries, but know that lenses will work on D60. Is this fixable, cheap, or should I look for another. Also will my lenses work on any other Nikon digital camera?

Cheers,
Bob

Thanks for the link. I wonder one thing though. When he shows F1.4 then F1.8 shot it gets brighter at F1.8, then continues to get darker as he hits F2.8 and F4

Did he reverse them on the video ?

There is a pretty good review of the new Sigma 35mm f/1.4 and it looks like the lens is awesome:

http://learningcameras.com/reviews/7-lenses/86-sigma-35mm-f14-review

donaldejose said:
Hence, if you are in low light and want to keep the full face reasonably sharp grab your D400 DX body because that allows you to do at f2.8 what you will need f4 to do if you are using your D4 body? Is this true?

No. The D4 must be light years ahead in IQ /ISO performance than any DX body - don't ever expect DX to catch up FX unless there are 5 years or so between models. So it would be more logical to up the ISO 1 stop on the D4 and still shoot at f2.8.

Slight error here. I am not trying to find what is "right." I was simply experimenting to find the minimum f-stop that would tend to keep that rear eye in focus when using classic portrait lenses in the 100mm range at a classic head and shoulders portrait distance. The rule of thumb seems to be f4 will do it on an FX body and f2.8 will do it on a DX body.

We could say DX gives you a one stop DOF advantage in low light when shooting portraits and trying to keep the full face in reasonable focus. This is not generally commented upon as an advantage to shooting DX. It may be a factor when the new D400 and D72000 come out if they have high ISO equivalent to the new FX bodies. Using f1.8 in DX(and equivalent lenses) will give you about the same DOF as f2.8 in FX and shooting at f2.8 in low light will give you about the same DOF as using f4 on an FX body. Hence, if you are in low light and want to keep the full face reasonably sharp grab your D400 DX body because that allows you to do at f2.8 what you will need f4 to do if you are using your D4 body? Is this true? Conversely, if you are working in f2.8 available light and want to blur the background more grab the FX body and shoot at f2.8 in FX rather than in DX because it will give you shallower DOF in the same light? Just have the model turn her head more directly to you to keep both eyes sharp (or do a profile where you won't see that rear eye or just let it blur).

Yes to all Donaldjose ...

Just a note - I am not much into portraits but when I do shoot some ( mostly my kids ) , I never stick to one aperture. f1.8 ( usually avoid ) , f2.2 , f2.8 , f3.5 etc. Trial and error doesn't cost a penny these days. So don't worry about getting it all perfect in all shots and remember there is no "right" - as you are trying to find - that works for all situations in photography.

Good reminder golf007 though I have rarely come up with any light requiring less exposure than 1/4000 f4 . Sunny 16 gives 1/4000 f2.8 ( f4 with base ISO 200 ). Surely of help if the intention is to go f1.8, f1.4 ...

Can we say, as a rule of thumb for use when setting up your camera for a shot, that an equivalent lens on a DX body when used for the same framing of the subject will give you a DOF equivalent to about one stop more in FX? Or stated the other way: FX provided about a one stop equivalent shallower DOF than does DX with the same f-stop and the same framing using an equivalent lens? Hence, in my example above of head and shoulders framing using equivalent lenses; the DX combo at f2.8 will produce DOF equivalent to the FX combo at f4 and the same would be true for DX f4 to FX f5.6 or DX f5.6 to FX 8? Is this DX/FX effect the source of the comment I have seen to the effect that "FX isolates the subject more?" I have always shot DX until a few months ago when I picked up my first FX body so I had no practical experience with that comment.

One thing that has not yet been brought up is the use of ND filters in order to achieve a shallower depth of field.

And I quote: "Although ND filters are primarily used to achieve longer exposures, a less common application is to enable a shallower depth of field in very bright light. For example, most SLR cameras have a maximum shutter speed of 1/4000 second, so a subject in direct sunlight might therefore require an f-stop greater than about f/4.0 (at ISO100). With a 2-stop ND filter, one could reduce this to f/2.0 — yielding a dramatic improvement in background blur and subject isolation....On the other hand, these situations are rare, and can usually benefit more from photographing the subject under dimmer (and likely less harsh) lighting. These situations are also unlikely to require anything stronger than a 2 or 3-stop ND filter."

donaldejose said:
Paperman: I understand needing to get close if you are using the same mm lens. But when you are using an equivelent mm lens you don't need to get closer. You are at the same distance from the subject with the same framing with a 60mm on a DX body as you are with a 85mm on a FX body. I tried it just this morning. So why wouldn't the DOF be the same? I don't understand.

Look at it this way then. You don't actually have a 75mm lens on the DX - it is a 50mm cropped into 75mm.

f-stop is the ratio of lens opening to focal length and we know it is the key factor in determining the DOF . Greater the opening, less the DOF.

The 50mm on DX ( acting like a 75mm ) STILL has the opening of a 50mm lens . It creates more DOF than the FX with 75mm on.

Hi all,

If you approach the calculator differently you'll get a different result. With the 60mm f2.8 at 5ft the DOF is _.23ft and the 85mm f1.8 at 7.5ft DOF is .24ft, but both yield the same frame equivalent and approximate DOF.

For me, the bokeh of the 60mm f2.8 or the 85 f1.8 are equally pleasing and I have both lenses and use them on the D7000. The DOF is more narrow with the 85mm, but the standoff is greater. The 50mm f1.8 is a much better 90mm/85mm 'workalike' in the DX world (with even a slightly shallower DOF), and I have that lens, too.

Things that are important are 'standoff' - how far you are from the subject, and how much room you have to work.

Also, and not trivial, for what use is the product to be used? Some folk are going to want a tad more sharpness in the faces of their loved ones. Printed content tends to muddy a bit, too, making a great blur a gamble, and lenses to tend to preform better at f4/f5.6 than at wide open. I keep that in mind when considering aperture options.

I'm not suggesting a return to the Group f64 (they were using view cameras - somethings were completely different), but it did precede the current trend it selective focus.

My best,

Mike

I would like to way my opinion here and let me know if I on or off base.

To my understanding is DOF has nothing to do with the sensor but is a combination of distance to target, f stop and focal length. I find it easier to think of everything from an FX perspective since that is what everything is base around. A 60mm lens is always going to give the same DOF regardless of the sensor behind it. All the sensor does is apply a crop to that image. So on a D800 with the 60mm all the DX sensor is doing is removing you from having to crop the image later. I find it best to think of it as using a teleconverter. If you put a 1.5 converter on that 60mm lens and take that shot from your D800 don't you get the same image, DOF and everything else? I think it might be a problem to think of lens on DX bodies as having a equivalent focal length to FX since you do not get those statistics. I prefer to think of them as merely a cropping tool.

Paperman: I understand needing to get close if you are using the same mm lens. But when you are using an equivelent mm lens you don't need to get closer. You are at the same distance from the subject with the same framing with a 60mm on a DX body as you are with a 85mm on a FX body. I tried it just this morning. So why wouldn't the DOF be the same? I don't understand.

It is all because with an FX body, you have to get closer to the subject to get it the same size it appears on a DX body frame.

This changes the ratio of distance "front of object" to distance "back of object", thus the difference in DOF.

Some discussion of DX v FX DOF with the same framing by the same lens is on another thread:

Here is an example: "Another way of looking at the FX vs DX DoF is if you want to get the same framing (i.e FoV) with the same 135mm lens on both FX and DX cameras then you'll have to move the FX camera closer to the subject and/or the DX one farther away. This will also create the effect of a greater DoF on DX and a more shallow DoF on FX." iris chrome

http://nikonrumors.com/forum/topic.php?id=6178&page=2

Notice iris chrome is taking about using the same lens on two different bodies. I am talking about something different: using equivalent lenses on different bodies.

Let's take my example of head and shoulders framing with an FX body using an 85mm lens and the same head and shoulders framing with a DX body using the 60mm Nikon Micro (a 90mm FX equivalent lens). In order to achieve the exact same head and shoulders framing the two cameras will be the same distance from the subject. Right or wrong? I tried it and I am standing the same distance from the subject at the same framing. Standing the same distance and using the same f-stops with equivalent lenses will produce the same DOF? Right or wrong? I don't really want to do another series of photos to test it so I used the DOF calculator [http://www.dofmaster.com/dofjs.html] to test equivalent lens/body combinations. It computes a DOF of 0.65 foot for a 60mm lens on a D7000 body standing 7 feet from the subject and a 0.42 foot DOF for a 90mm lens on a D800 body standing 7 feet from the subject. If we input a 60mm lens on a D7000 body at f2.8 the DOF calculator gives us a DOF of 0.46. So Paperman seems to be correct that the FX format produces a shallower DOF at the same f-stop, same distance from subject with equivalent lens then the DX format produces. There seems to be a one stop equivalent DOF difference. If you are shooting a 60mm lens on a DX body you would have the same DOF at f-2.8 that I had a f-4 using a 85mm lens on an FX body. Thus, when I say f-4 provides a reasonable balance between DOF and bokeh for classic portrait lenses with classic head and shoulders portrait framing would that same DOF balance exist at f-2.8 if you were shooting a 60mm lens on a DX body? Is that what the DOF calculator shows? Or am I doing something wrong here?

It seems to me if I am using the DOF calculator correctly f2.8 on a DX body with a 50 to 60mm lens should keep both eyes reasonably in focus while you need f4 on an FX body with an 85mm lens. Is that correct?

I don't understand why the optics would not yield the same DOF with equivalent lenses standing the same distance from the subject with the same framing. It seems the optics would be the same in that situation and you would have equivalent DOFs with equivalent lenses.

donaldejose said:

As to DX sensors, many of the photos in this thread were taken with a DX sensor body. I would think a 50mm lens on a DX body would equate to 75mm and an 85mm lens on a DX body should equate to 127.5mm or a 60mm macro lens on a DX body would equate to 90mm so when you use any of those lenses on a DX body and frame your subject head and shoulders I would expect the f-stops would be about the same as I found for 85mm on a FX body. Why don't you try it if you have 50mm or 60mm or 85mm and a DX body and post your results? Are the eyes on DX at f-4 different than mine? I would be interested to know.

50mm on DX is 75 mm on FX - that much is true. However, DOF at 50mm on DX at a certain f-stop is NOT equal to the DOF at 75mm at the same stop on FX. So you can not make that simple conversion. Full format provides shallower DOF.

Paperman: Sure, f2.8 (and maybe f2?) will work if the face is flat to the camera and more than f4 would be better if the face is turned more away (but if turned much more you won't even see that rear eye to worry about whether or not it is in focus!). I was just looking for the minimum f-stop which would work at head and shoulders distance with a lens from 85 through 105mm: the classic portrait lens and the classic head/shoulders portrait distance. This is all about head shots where you are not blasting the subject with light. In the studio one usually uses f8 and there have been a number of studio shots on PAD recently at f11 or so. If you want to do a half or a whole body portraits you may be using 50mm on FX and 35mm on DX and you will have a different DOF at f4. My originally stated constraints were: What f-stop are you going to need to bring that rear eye into reasonable focus so it is not so obviously out of focus when you frame your subject head and shoulders with a classic portrait lens? The distance from the subject is subsumed in that constraint. I tested it, tried to illustrate my results and found that unless the face is directly facing you the rear eye will be significantly blurred at f1.8, f2 and starts clearing up (acceptabley?) at f2.8 and generally is acceptable at f4. Unfortunately, my original photos were biased by a front focus issue with this body/lens combo and so I re-shot these examples one I corrected the front focusing. That's all. That's what I found and shared it here for anyone interested in the subject. Of course, those f-stops apply only to the original constraints of using a portrait mm length lens at head and shoulders distance for a classic portrait look. Other lenses and other distances were not tested by me and may well have different minimum f-stops for a reasonably sharp rear eye.

As to point of focus, I mentioned that the small AF sensor spots in the D600 are a help because they are small enough to let you attempt to focus just on the near eye tear duct (or as you might say, the near side of the nose). These are just starting places for the effect you want to produce if you are shooting head and shoulder portraits and you don't (or cannot) blast the subject with strobes. F-4 is a nice compromise because it allows for reasonable depth of field and reasonable bokeh (as long as there is some distance between the subject and the background). That is all I am saying, and trying to demonstrate, here. You can see the bokeh produced by f-4 in the portrait I just posted on PAD.

As to DX sensors, many of the photos in this thread were taken with a DX sensor body. I would think a 50mm lens on a DX body would equate to 75mm and an 85mm lens on a DX body should equate to 127.5mm or a 60mm macro lens on a DX body would equate to 90mm so when you use any of those lenses on a DX body and frame your subject head and shoulders I would expect the f-stops would be about the same as I found for 85mm on a FX body. Why don't you try it if you have 50mm or 60mm or 85mm and a DX body and post your results? Are the eyes on DX at f-4 different than mine? I would be interested to know.

Very nice images shared - no argument about that. Therefore it is a nice topic to follow; a lot to learn from portrait masters ... Some images are truly breathtaking ...

However, I still can't seem to understand the struggle ( from Donaldjose ) to generalize the f-stop to be used for getting both eyes in focus. I mentioned my concern for neglect of distance before, I will mention the angle the face makes with the camera now. f4 may be OK with this angle and this distance but what if she turns her head a bit away - increasing the distance between both eyes ?. f4 won't be enough then . What if she turns towards the camera to an angle which will make f2.8 possible ? What about focusing in between the 2 eyes; won't that change things ?

And what about those using APS-C sensors ? More than half in this forum are on a different format which makes these generalizations meaningless .

You have to know Donaldjose that every portrait is different; what you want to see in every portrait is different . With so many variables, you can not just pick an f-stop and say this works for all.

Once more, wonderful portraits from many participants ...