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Friday, 5 September 2014

FZ1000 Extra Zoom Options


Noisy Miner FZ1000 RAW capture, cropped output to JPG.
The FZ1000  has a very versatile 16x zoom lens with a full frame equivalent range of E25-E400mm. This is more than enough for most types of general photography but some owners want to photograph birds and other wildlife  and that may require a longer reach.
There are 5 ways to achieve this:
1. Fit a teleconverter optical unit to the front of the lens. I have read several reports on user forums and elsewhere of a variety of approaches to this method.  Some users have reported  satisfactory results, others poor results. There are several problems:
* Considerable variation in  optical performance of various units from different makers.
* The unit has to be affixed to the camera/lens somehow. If one is screwed to the  filter thread it's mass must apply significant torque to the inner lens barrel, possibly  leading to decentering and excess load on the zoom motor.
* The OIS system will not be calibrated for the extra lens element.
* This approach requires the user to carry, in effect, an interchangeable lens. For me the key appeal of the FZ1000 is that it frees me from having to manage interchangeable lenses.
So I will not discuss this option any further.
Swamp Hen FZ1000 I-Zoom
2. Shoot RAW, crop. This one is straightforward and would likely appeal to RAW shooters. But plenty of users prefer to shoot JPG for a variety of reasons and there may be operational benefits to JPG capture. 
The next three methods are all JPG only.
3. Extra Optical Zoom.  (Ext.Opt.Zoom)  This is enabled in most capture modes  if Picture Size is set in the Rec Menu to [EX M 10Mpx]  which allows up to E560mm focal length,  or [EX S 5Mpx] which allows up to E800mm focal length.  Normal control of the AF box is retained.
This option is not available if picture size is 20Mpx.
Note the list of settings on page 198 of the Manual which are not compatible with Extra Optical Zoom.
4. Intelligent-Zoom  (i-Zoom).  If i-Zoom is  On in the Rec Menu, Page 6/7  (set quality to JPG first or the tab will be greyed out) and Quality is JPG then i-Zoom will be enabled in most capture modes. 
The longest equivalent focal length available is E800mm.
Normal control of the AF box is available.
Note the list of settings on page 198 of the manual which are not compatible with i-Zoom.
5. Digital Zoom. The tab for this appears just under  i-Zoom on page 6/7 of  the Rec Menu. Quality must be JPG. Longest equivalent focal length is E1600mm.
A fixed, large AF box appears when Digital Zoom is set and the focal length is greater than E400mm. The AF box behaves normally when the focal length is less than E400mm.
Note the list of settings on Page 199 of the Manual which are not compatible with Digital Zoom.
FZ1000 I-Zoom

How do these zoom features actually work ?   There is no explanation in the Owners Manual. Each of the JPG extra zoom methods appears to involve a non optical technology. When I zoom in Ext.Opt. Zoom and look into the lens, I see no movement of optical parts. So I am not clear why this technology has the word "optical" in the name.
Ext.Opt. Zoom delivers a file with reduced pixel dimensions.
Presumably each involves cropping a variable amount from the full frame.
Both  i-Zoom and Digital Zoom produce 20Mpx files. Presumably this is the result of interpolation similar to that which occurs in Photoshop when one is upsizing a file for large format reproduction.
There is no explanation in the Manual for the different maximum E-Focal length possible with each method.
Spinebill  FZ1000  This is not a great photo but I show it here because it was remarkable that I was able to make any photo at all. Spinebills flit about with great speed never stopping in one place more than a second or so.  The light weight, fast AF and quick responsiveness of the FZ1000 allowed me to grab this shot even though the bird stayed in that spot for only a second.
Why does the FZ1000 have three different types of E-Zoom ?  I really can't figure this out.
Which is best ?  The Owners Manual describes each of the electronic options for increasing zoom range but does not indicate which is best or why you might choose one in preference to the other.  In addition the Manual makes reference to image quality in terms which are difficult (for me anyway) to understand.
The description of Extra Optical Zoom (page 198 of the Manual) says........."You can zoom in further than you can with the optical zoom without deteriorating the image quality".  It is not clear what is meant by this.  Maybe they mean that the image quality with full zoom is not less than the image quality without full zoom  at picture size 10Mpx or 5 Mpx.
The description of i-Zoom refers to "minimising deterioration of the image quality".
The description of Digital Zoom is a bit more candid, ...."image quality deteriorates every time you zoom in further"..........
My tests show that is equally true of  all the Extra Zoom approaches.
Comparison Table

Method
Longest
E-Focal length available, mm
Picture size, pixels
Presets required
Notes
i-Zoom
E800
5472x3648,
19.96 Mpx
JPG
 i-Zoom On
Can leave
i-Zoom On
Note exceptions
Ext.Opt.Zoom
E560
3888x2592
10Mpx
EX10Mpx
JPG
Note exceptions
E800
2736x1824
5Mpx
EX5Mpx
JPG
Note exceptions
Digital Zoom
E1600
5472x3648
19.96 Mpx
JPG
Digital Zoom On
Note exceptions

User Experience  Having tried the four approaches which do not require an extra lens, I have found that i-Zoom is the most user friendly.
* There is no need to enter a menu or press a button to engage i-Zoom. If i-Zoom is On in the Rec Menu and Quality is JPG then i-Zoom is active when the zoom ring (or lever) is turned towards infinity.
* You have full control of the AF box size and position.
* This is an assumption but I would guess that metering and OIS are calibrated for the longer effective focal length and smaller field of view.
* The maximum effective focal length of E800mm is consistent with decent picture quality and is also reasonably easy to use hand held. The longer effective focal lengths enabled by the other methods lead to lower image quality and more difficulties with framing, focussing and camera shake.
Ext.Opt.Zoom requires a reduced Picture Size which requires a trip to the Rec Menu or Q Menu or using a Fn button for Picture Size.
Digital Zoom loses control of the AF box just when you need it most, at the long end of the extended zoom range.
RAW cropped may require a focus box quite small relative to the frame which could lead to focus problems. Metering will be for the larger area most of which will be cropped.

Adding Zoom Types  It is possible to add i-Zoom or Digital Zoom to Extra Optical Zoom for an even greater effective focal length. Be prepared for some obvious loss of picture quality if you do this.

Chart Tests  I photographed a test chart using RAW cropped, i-Zoom, Ext.Opt.Zoom and Digital zoom. I adjusted the files in Photoshop so each was the same resolution  (in pixels per inch) and same picture size (in centimeters width and height). It was difficult to tell one from the other. I concluded that for practical purposes there is no benefit to picture quality of one over the other.
Resolution was obviously less than I found from the FZ1000 at E400mm which is the limit of optical zoom.
Photo Style Settings   Each of  the three "electronic" extra zoom methods produces a JPG which is affected by the Photo Style settings at the top of the Rec Menu. These settings are subject to personal preference and will also be influenced by your work flow. I will usually run JPGs through Camera Raw so I like low contrast files to retain as much highlight detail as possible.  I also feel  that JPG noise reduction is more damaging to picture integrity than noise, so I use the least possible noise reduction.
This is a work in progress but my settings for Photo Style [Custom] are Contrast -4, Sharpness 0, Noise Reduction -5, Saturation +3.
Summary  There is no free lunch and there are no miracles. Any of the extra zoom methods delivers resolution lower than what can be achieved at the limit of optical zoom, However the extra zoom methods are definitely useful especially for birds, wildlife and similar subjects with sufficient quality for modestly sized prints. 
I find that i-Zoom is the most user friendly.   It  allows you to have E800mm at f4 with OIS fully operative.
Consider the alternatives.
The FZ200 has E600mm at f2.8 with decent picture quality for small prints.
There is no option for E800mm at f4 in the full frame world.
Using an APS-C body one could use, for example, the Canon 400mm f2.8 which with a 1.4x teleconverter gives E896mm f4. Which sounds quite appealing until you realise that with camera and T/C  this kit costs about $16000 and weighs about 5 Kg. Ouch. And that lens is not useful for most general photography.
Conclusion  i-Zoom is definitely worth using when the subject requires more reach than the standard E400mm can provide. No additional equipment is required. Normal control of the AF box, metering and OIS are available. Quality is good enough for small prints.

Update June 2015:   Since the original post above I have been further researching the subject with a variety of subjects.
In most situations I have found that I can get a better result by shooting RAW (at Focal Length Equivalent 400mm)  and cropping as required.
There is more opportunity to retain visual information and more highlight and shadow detail (dynamic range) in the RAW files.  I particularly find better retention of highlight detail with the RAW files.
But i-Zoom remains a useful option for JPG shooters provided subject brightness range is not very high.
I find that picture quality with any method is quite decent up to about FLE 800mm, but declines markedly after that.





3 comments:

  1. Optical in Extra Optical Zoom (EZ) refers to the fact that the zoom is purely optical, without digital interpolation; i.e., the sensor image is simply cropped. This will give the best IQ even if more MP is needed since interpolation in PP can be better than in camera (and more MP is often not needed). The advantage over cropping in PP is that only the desired image area is metered and focused.

    i.Zoom and Digital Zoom both use digital interpolation. The difference is that i.Zoom has a more limited range in order to minimize IQ degradation, but there is still degradation.

    The zoom range difference between EZ and i.Zoom is relatively small. Since I rarely need more MP, I generally prefer EZ to i.Zoom.

    The FZ200 actually produces very good full res IQ at max zoom and aperture in good light (at up to 1/1000 shutter speed -- higher shutter speeds have more noise).

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  2. Shoot RAW always! I have found that Topaz Gigapixel delivers excellent results for upsizing cropped images.

    The workflow is as follows: Do most adjustments in Lightroom (or your editor of choice) INCLUDING cropping.

    Export the image as a TIFF with ProphotoRGB colorspace to maintain as much data as possible. Open in Topax Gigapixel and upsize with TIFF output back to Lightroom, then export as JPEG.

    Excessive cropping likely will increase the noise in the image, so consider using Topaz Denoise AI before going to Gigapixel. In all steps, use TIFF format in ProphotoRGB colorspace outside of Lightroom when going to Denoise or Gigapixel.

    ReplyDelete
    Replies
    1. Yes, RAW is best for stills, but my own workflow is simpler:
      1. Import into Photoshop with Adobe Camera Raw.
      2. Noise reduction with Neat Image.
      3. Resize (if needed) with PhotoZoom.

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