DX Lenses should be brighter/faster than FX lenses

spraynpray

We don't want this to become DX Vs Fx, but my best images so far look like this: 80% DX and 20% FX which proves to me that the best images come not from the glass or the format, but from the opportunity presented.

Ironheart

I am always fascinated by DOF discussions, as in my experience, the only significant differences occur when looking at f/1.8 vs. f/5.6, or at least several f stops difference. My perfectionistic issues, not always good, lead me into the thinking that DOF is in almost all cases, much less than any calculations, and I attempt to focus on what I think is the key to producing a good image.

This is exactly why DoF is defined as "viewed from a certain distance at a certain size"
If you stare at 400% pixels, you will suddenly find your DoF is very shallow. However when viewed at 50% the DoF will be deeper. There are some DoF calculators that take final print size, and acuity of eyesight (20/20 vs 20/30, etc..) into consideration.

For Full Frame (FX) 35mm still photography, the standard circle of confusion is usually chosen to be 1/30mm (0.030mm) Because the human eye is capable of resolving a spot with diameter about 1/4mm (0.25mm) on an 8x enlargement (8" x 10") held at 25cm distance from the viewing eye. The 0.25mm corresponds to a spot with diameter 1/(8 * 4) ~ 1/30 mm on the 35mm negative.

So @msmoto you are just looking too closely or your eyes are too good

heartyfisher

:-B

Msmoto

Must be too closely.....eyes, very old.... :-B thank you heartyfisher

haroldp

DOF is largely a function of ones personal tolerance for unsharpness. Guidelines for print size and viewing distance in museum or gallery displays are largely irrelevant in the digital world where viewing magnification is much greater.

That is why many lenses that were thought 'perfect' on film are being replaced by all manufacturers with sharper ones.

Summicron's of course are still perfect.

9viii

heartyfisher said:

"Motion blur should be no different as long as your field of view is the same." ??

You may be assuming the shutter speed is the same .. the argument is because the aperture is wider we can get a faster shutter thus reduce motion blur.

Full Frame inherently has a 1 stop ISO advantage, you need two extra stops of aperture to have a faster shutter speed and equivalent image noise.

heartyfisher said:

So the trade of is ... lets do a comparison
D5 + 70-200 VR F2.8 vs D500 + 50-100 F1.8

1) Noise Sensor IQ the same - bec the D500 can run at 1+ stop ISO lower due to the faster aperture.
2) AF - Advantage to DX bec of Brighter aperture.
3) VR - advantage to FX the FX lens has VR
4) Subject Movement - Advantage to DX bec of faster shutter speed available.
5) DOF - advantage to DX bec of deeper DOF esp at low apertures ... ;-) ( actually no difference ;-) )

So Overall DX comes out ahead ... ;-)
( not mentioning the Price difference ;-) , Weight. etc...)

In this list, if point 1 is true then point 4 is not. If point 4 is true then point 1 is not.

heartyfisher

@9viii : re point 1 and point 4, You are of course right :-) but you can choose which way you want to compromise :-) or compromise and go FX ;-)

My comments are "slightly biased" towards DX I know ;-) just having a go at the "FX is always better" crowd ;-) lol! I am a cheeky bugger sometimes

Still the ISO difference between DX and FX has always been about 1 stop( generally less due to generation cycle times being faster on DX) as I have mentioned many times in many threads, in the older generation when the iso range was low ie about 3ev(DX) vs 4ev(FX) sure it made impact for some people who wonder away from base ISO .. as tech improves ISO difference is playing a smaller and smaller part even for those few who wonder. These days eg: D500 vs D5 we have 9-14 ev range vs 10-15ev . For most types of photography and most photographs base ISO is where we want to be.

spraynpray

@Heartyfisher: " just having a go at the "FX is always better" crowd "

Too right! :P

WestEndFoto

I am curious who you guys think forms part of this crowd?

heartyfisher

WestEndFoto said:

I am curious who you guys think forms part of this crowd?

:@) 3:-O ~:> :bz

:-) dunno .. I think its self selecting ... I am one sometimes I think :-)

spraynpray

WestEndFoto said:

I am curious who you guys think forms part of this crowd?

Pretty much most people on NR that have FX would be my honest answer, but the real fanboys that think anything other than FX is pretty worthless are the smaller group that it was aimed at. I have both but think that the DX's have come so far since the old 12mP bodies that it is splitting hairs - especially when the mP count is the same (D7100/D750).

donaldejose

I think the "correct" DX vs FX comparison will be between the D500 and the D5 because their feature set (mp, focusing, in camera image processing, etc) are pretty much the same. I expect most things to be a wash except I do expect the D5 to be about one stop better at ISOs like 3,200 and 6,400 and 12,800 simply because the larger FX sensor captures more light with which it can make an image. There is one other thing where I I expect DX vs. FX may make a difference and that is very big prints (greater than 24 x 36 inches). An FX image doesn't have to be enlarged quite as much as a DX image or maybe that old "enlargement" issue become irrelevant when the sensors have the same megapixes and produce the same size files. While that won't make any difference at 8x10, 11x14 and 16x20 it may make some difference above poster size. Since I expect about a one stop ISO difference a person would have to compare a 6,400 ISO DX file with a 12,800 ISO FX file when both are printed to 24x36 inches. For perhaps 95% of photographer such large prints at high ISO will not be something they need their camera to be able to do. It will be interesting to me to see how wedding photographers feel about the D500. Will it have good enough fast wide angle lenses so it can capture the church interior and attendees? Will it's high ISO images be good enough for shots in churches during the ceremony without using disrupting flash? I think it will. But we will see.

Ironheart

Nikon is pretty much cluing us in that there is a 1-stop difference between otherwise identical cameras with the max ISO and extended ISO. The only difference is that of geometry, meaning you get a stop more light to play with on FX.

donaldejose

Agreed! Paying $4,500 more for one stop better ISO, a built in grip and a longer shutter life seems to be too high a price to pay which makes the D500 a great deal.

Nikoniser

I have a D810 and a D7100 and my D810 murders the D7100, the difference is way bigger than 1 stop, the colours, skin tones in particular in the D7100 go to hell so quickly at higher iso's, the highlight headroom is way less, much harder to pull the shadows up, D810 is much less sensitive to certain lens issues ( in the centre anyway - for example my 105 VR shows blue CA in the centre on the D7100 and virtually none on the D810 ) I would love to be able to leave the D810 in the studio but its simply the better camera 99% of the time in the real world, the images that come out of it are just so natural and so malleable. People chuck the phrase "a stop" around so casually - a stop difference means TWICE as good, if a camera has a stop of iso, a stop of DR and and a stop of colour accuracy its a BIG difference !

manhattanboy

Nikoniser said:

I have a D810 and a D7100 and my D810 murders the D7100, the difference is way bigger than 1 stop, the colours, skin tones in particular in the D7100 go to hell so quickly at higher iso's, the highlight headroom is way less, much harder to pull the shadows up, D810 is much less sensitive to certain lens issues ( in the centre anyway - for example my 105 VR shows blue CA in the centre on the D7100 and virtually none on the D810 ) I would love to be able to leave the D810 in the studio but its simply the better camera 99% of the time in the real world, the images that come out of it are just so natural and so malleable. People chuck the phrase "a stop" around so casually - a stop difference means TWICE as good, if a camera has a stop of iso, a stop of DR and and a stop of colour accuracy its a BIG difference !

When viewed at 150% or larger, I can instantly tell the difference between the two (810 and 7100). Viewed at smaller than 100% there are not that many differences that I easily notice between my 810 and 7100, but to be fair I am always correcting in RAW first, so the final output is pretty close. The pics I have highlight or shadow trouble on occur just as often on the 810 as the 7100 (hard to cheat physics LOL).

WestEndFoto

Agreed. My wife's D5500 looks like crap at ISO 800 and my D800, which is a generation behind the D5500, at ISO 800? I can barely tell the difference between ISO 100 and 800.

Now anybody that thinks that I am an FX fanboy should consider two things:

1.
In addition to my D800, I have purchased two DX cameras and a CX camera in the last three years.

2.
Read my profile on my Flickr account. Go to "westendfoto" on Flickr.

Ironheart

@Nikoniser @WestEndFoto You guys are comparing apples and coconuts. The point is we have a rare set of twins (last time it happened was with the D3 and D300). This will give us an opportunity to see how two otherwise identical cameras handle noise, IQ, etc... Kinda like two black holes colliding and sending out gravitational waves. Sorry wrong forum.

heartyfisher

Gravitational waves! existence finally confirmed !!! so awesome ! sorry excuse my geekness leaked... its been good D500, Gravitational waves, 50-100 F1.8 ...

Yeah, got to agree with the apples and coconuts though .. D5500 costs about 1/4 the price of a D810. BUT for many the IQ would be indistinguishable.. especially if you stick a 50-100 F1.8 on it.

@WestEndFoto Nice images !!

But as you well know and testify the D5500 can produce nice images too .. https://www.flickr.com/search/?sort=interestingness-desc&text=D5500&advanced=1

Do we dare start a tread called "DX Advantages vs FX advantages" .....
oh we have several already LOL !!.

DaveyJ

Pre orders on the D500 are very high. So that verdict is already in. Question here is will we buy more than one?

DaveyJ

To target my comment on DX lens should be faster than FX......the lens we will be using on the D500 are already owned by us! Nikon might decide to make some prime fast lens but here we do not need or want them. Our one 35 Nikkor DX f1.8 gets very little use these days.

retread

DaveyJ said:

To target my comment on DX lens should be faster than FX......the lens we will be using on the D500 are already owned by us! Nikon might decide to make some prime fast lens but here we do not need or want them. Our one 35 Nikkor DX f1.8 gets very little use these days.

May I ask what lenses you use. I also have the lenses I will use for now. All Nikkor FX except on the wide end where I have third party DX zooms. Most of my shooting is wildlife and sports.

I have not ordered a D500 yet as I want the money in my pocket first.

Msmoto

"I have not ordered a D500 yet as I want the money in my pocket first. "

Since when did NAS become affected by whether we could actually pay for it...?

retread

Msmoto said:

"I have not ordered a D500 yet as I want the money in my pocket first. "

Since when did NAS become affected by whether we could actually pay for it...?

I guess I am old school. If I can't pay for it I don't get it.

heartyfisher

Another nice DX lens that has a wide aperture .. Tokina AF 14-20mm F2.. Announced end of last year .. in case some of us missed it..