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Hi Guys-Gals my gear is D300+D700
Sigma 120-300f2.8----sigma 1.4 TC
Nikon 80-400VR
several smaller lens
my question is can I compare image quality of D300 with crop factor with the D700 as full frame as both bodies are the same pix count.Assuming good lighting conditions.I was starting to look for longer legs to shoot Polo at 300x160 yards you can be a long way from the subject.Any experience??ps will the Kenko 1.4tc work with the 80-400
cheers InMotion

Yes you can, but why?

What is the point?

What is it that you are wanting to know? Your question is not that clear to me, and I cannot understand where you're coming from, or what you really want to achieve with this comparison.

Is there perhaps a better way that you can express your question?

I think you are asking if you could say compare a shot taken with the D300 with a 200mm lens to one with the D700 with a 300mm lens. While the angle of view will be the same and from the same distance you will be able to fit the same amount of subject in, other aspects will change.

The D700 will still have better IQ because the photosites are larger. This includes better high ISO performance.

The depth of field will be different. For a given f/stop, the D300+200mm lens will have a greater depth of field than the D700+300mm lens. This should be noticeable in the images with larger apertures.

As a general concern, the further you are away from the subject, regardless of the gear you are using, you will start to lose image quality because of the increase in air through which the light has to travel between the subject and the camera. Humidity, dust and even heat will degrade the quality of the image.

I'm a bit confused, you have both bodies so how come you can't compare the IQ on both examples yourself ?

For me, I have a D300 and a D3 and if the light is OK then I will use the D300 only if I really need additional reach, the less the crop the better imho. If reach not an issue then the superior IQ and AF of the D3 excels.

I must admit though that even with the crop there is something about D3 images that make it a compelling camera to use no matter what and sooner or later you will do what I did and get longer glass.

HI Kiwi has hit the nail on the head.As I take a lot of shots it seems better to use the D300 if light is good.as I can selectively frame the shots.Alsothe viewing public do not like images that need heavey cropping.This I was pretty much aware of but just wanted to confirm this.I am trying to use the 80-400 VR to avoid purchase of a Bigma,I am interested in trying it with a 1.4 TC as this will give me the reach I need with my D700. cheers inmotion

Now I am really confused, dont you have 120-300 with a 1.4tc. Thsi is much better quality than Bigma

By the way I doubt general public could tell a crop unless it's REALLY bad.

We can though, lol

inmotion wrote:Alsothe viewing public do not like images that need heavey cropping.

They shouldn't know, and it shouldn't matter.

If they can tell, then something else is happening, either in your shooting, or in your workflow.

I am trying to use the 80-400 VR to avoid purchase of a Bigma,I am interested in trying it with a 1.4 TC as this will give me the reach I need with my D700. cheers inmotion

Ok, a few points here.

First of all, what benefits do you believe the Bigma will give you over the 80-400? It does not have the acuity, and you should get a far better image - even cropped - from the 80-400 than you will from the Bigma.

Does the 1.4 even work with the 80-400? I'm not sure that it does, but I would not be recommending it.

As to the "reach that you need" with the D700 ... The D300 has a greater sensor density than does the D700. This means that the D300 enjoys a higher resolution than does the D700, and thus images shot with the D300 will tend to be able to crop to a greater level than images made with the D700.

But because of the fatter pixels in the D700, those images should still be bloody good, and well capable of a significant level of cropping. You should consider looking at the images of Chris - sirhc55 - where he has made them with a 4MP D2H.

Again, if you are not getting satisfactory crops, I would be looking at workflow and technique, unless you're actually trying to crop to some sort of silly level.

How are you judging these things?

Whilst the D300 does have slightly higher density than the D700 (roughly 12.1 vs 12.3) this difference is easily compensated by the fact that the D700 photo receptors are roughy twice the size of the D300 - which gives a lot less noise.

Crop-wise you obviously wont have to crop the D300 images as much as the D700 with the same lens combo to get a particular image, it really comes down to how far away you are from what you really want to get an image of.

The crop factor on the D300 will mean you will have to crop less than a shot taken with the same lens on the D700. But as they are both ~12MP cameras I would have thought you could still crop to a similar degree with them (ie chop the centre 50% out of a D300 shot would look the same as a the centre 50% of a D700 shot - with equivalent lenses and in good light). Am I missing something?

Absolutely.

HI my try at a final explanation.the sigma 1.4TC was purchased as a match to the120-300f28 and is satisfactory.I recently photographed horses at 80m range with the sigma 120-300/d700 and decided to swap to the d300/120-300
and i was intruiged by this.What i mean by the crop is that I run a site computer and down load every 2 hs thro the day
thus allowing competitors to view "off camera Images".Thus the images taken with the D700 are approx 30% smaller if taken at max zoom and in off camera condition are less impressive and harder to see .I really appreciate the advice given on this forum and if this discussion has reached a conclusion I am happy to close.One question is still .Does the kenko 1.4TC work with the 80-400vr.This because i recently took some bird(feathered) shots with the d700/80-400vr and was very dissapointed with the softness,as all shots were less than 20m and some 4-6m.I may not have the focus sorted yet but a couple of shots of birds on the ground(graphically shows the fous point) indicated that the focus was ok--inmotion
and thanks for the patience

Now, I think that we're starting to get somewhere.

inmotion wrote:I recently photographed horses at 80m range with the sigma 120-300/d700 and decided to swap to the d300/120-300 and i was intruiged by this.

Yep.

What i mean by the crop is that I run a site computer and down load every 2 hs thro the day thus allowing competitors to view "off camera Images".

Good idea.

Thus the images taken with the D700 are approx 30% smaller if taken at max zoom and in off camera condition are less impressive and harder to see .

Yep. This is the crop factor (on the D300) at work. You could switch the D700 into crop mode, and then you would get images that looked similar in size within the constraints that you're describing here. That would, I expect, overcome the "problem" that you're describing.

However, in so doing, you would be switching the D700 into its 6MP mode, which would yield lower resolution images.

This does not mean that the images would be of a lower quality, however: the D700 images are luscious, and the reality is that whether you shot in crop mode, or in FX mode with the outcome that the images appeared "smaller" when being viewed as you're describing, the actual images that you would be working with, from the D700, would be, for all intents and purposes, of the same resolution and parameters.

I really appreciate the advice given on this forum and if this discussion has reached a conclusion I am happy to close.

The only person who makes that decision is you. If you still have questions, ask away; we're not going to shut this down on you.

One question is still .Does the kenko 1.4TC work with the 80-400vr.This because i recently took some bird(feathered) shots with the d700/80-400vr and was very dissapointed with the softness,as all shots were less than 20m and some 4-6m.I may not have the focus sorted yet but a couple of shots of birds on the ground(graphically shows the fous point) indicated that the focus was ok--inmotion

I believe that the Kenko does work, but again, I'd be reluctant to go down that path.

What aperture were you shooting at? What focus mode was the camera set to? Are you using the focus limit switch on the lens? Perhaps you can post some examples of the images that you're not satisfied with?

and thanks for the patience

Not a problem.

hi Gary,Yes good progress now.I will admit that I was unsure of the function of the" Limit-Full" switch to control focus limits.In a walkaround situation looking for macro shots of flowers and birds--yes i know two different subjects.I set apature control f10 AWB ISO 500 (to gain 1/250 in the lower light spots)when I shot birds with a full sky (bright) backround the speed was 1/1250--1/2000
Some of the flower shots were good but all of the bird shots were soft.
Your suggestion to switch to DX will be something I play with --thanks.
Prior to this post and in the never ending search for the right glass I shot with my 80-400VR the sigma 120-400OS(as a direct replacement possability for the 80-400VR) and the Bigma.
All lenses had 3 zoom length shots and the bigma an xtra at 500mm.
My evaluation was
1st sigma120-400OS
2nd Bigma
3rd 80-400VR
The true answer may be that I need more play time with the nikon or it simply needs a service(recent aquisition)
I would love to post images but i dont know how .maby thanks for your advice--inmotion

inmotion wrote:I will admit that I was unsure of the function of the" Limit-Full" switch to control focus limits.

Ok ... I thought as much. This is an important setting, as it helps you to improve the lens's apparent performance. And I think that a failure to understand its proper operation is one of the reasons some people don't like the lens. IOW, operator error.

When it's disabled, your lens is free to travel through its full focus range, and it will. This means that it may also hunt for focus if focus cannot easily be acquired. Of course, with a greater range to traverse, the focus mechanism, which is not the fastest in the world to start with, it must operate more slowly.

When you enable this switch, you need to pay close attention to the current focus setting on the lens at the time you enable it. It can operate in either of two ranges, those being, for want of a simple way to put this, near or far.

If your focus point is set to something fairly close, then it will only operate within a range that accommodates items that are close to you; the manual will give you the exact meters within this range.

If your focus point is set to something that would be some distance away (say infinity) then your lens will only operate within a range that accommodates subjects that are further away. Again, the numbers are specified in the lens's manual.

The upshot of this is that you are, in effect, able to convert the lens into ... two lenses: one for close items, OR one for distant items. With the limiter enabled, it's an either/or situation, but by reducing the distance that the focus mechanism may travel, you have significantly improved the apparent performance of this lens.

Of course, you need to be aware of your current setting on this lens, and if your subject traverses the near/far boundaries, then you need to disable, focus, and then re-enable, but I think that this would be a rare occurrence.

Play with the settings, and definitely familiarise yourself with how it works.

Also, look for situations where you can pre-focus or use trap focus techniques. As you learn about using this lens, and how best take advantage of it, you will become more comfortable, and produce better images.

In a walkaround situation looking for macro shots of flowers and birds--yes i know two different subjects.I set apature control f10 AWB ISO 500 (to gain 1/250 in the lower light spots)when I shot birds with a full sky (bright) backround the speed was 1/1250--1/2000
Some of the flower shots were good but all of the bird shots were soft.

Yes, two very different subjects.

The 80-400 is not a macro lens, so I guess you mean that you're just trying to take close-ups of flowers. In this instance you should switch the limiter into its near mode. I would caution against AWB, but that's a whole different discussion. ISO 500 is good for these, especially when using f/10, which should be right within the lens's sweet spot, and you say that you're getting good shots within this realm, so that's all good.

For the birds, you should be in the far mode for the limiter, I would be using something like f/8 through f/13, "A" mode on the camera, and let the camera deal with the shutter speed. Again, ISO up to 800 should be fine. Be aware that when shooting birds against a bright sky, you may need to introduce a little exposure compensation, and the subjects could be quite heavily backlit. If you're seeing this, experiment with settings in the +.7 - +1.7 EV range.

Play with different focus modes, and see which ones work for you. it will be the combination of focus mode selection and focus limiter that will be your key to getting this to work for you. Shoot, and then shoot some more.

Your suggestion to switch to DX will be something I play with --thanks.

You're welcome.

Prior to this post and in the never ending search for the right glass I shot with my 80-400VR the sigma 120-400OS(as a direct replacement possability for the 80-400VR) and the Bigma.
All lenses had 3 zoom length shots and the bigma an xtra at 500mm.
My evaluation was
1st sigma120-400OS
2nd Bigma
3rd 80-400VR
The true answer may be that I need more play time with the nikon or it simply needs a service(recent aquisition)

My inclination is to say that you need to work with the lens a little more. I doubt that it requires service, but did you acquire it new or pre-owned? The 80-400 is a very sharp lens.

In terms of outright sharpness and contrast (contrast affects how we perceive the sharpness) you should find the 80-400 at the top of your list, and the Bigma at the bottom.

One other point that may be worth noting is that both of your bodies permit you to fine tune your camera to each of your lenses. It may be worthwhile reading the relevant section of your manual and seeing if that can help improve matters for you.

I would love to post images but i dont know how .maby thanks for your advice--inmotion

Please review this post

Many thanks Gary I will definitely have a serious "evaluation Play" with the lens.as I use my own extensive web page i will try to digest the suggested link to post a couple of images as i am very keen to recieve comments/suggestions
Cheers inmotion
web address www.inmotionphotography.ifp3.com