Sony PXW-FS7 with or without lens

Categories: Miscellaneous 7 Comments

Sony-lens

This is the lens most associated with the new Sony PXW-FS7 its the Sony “G” 28-135mm f4 G lens, I will assume the 28-135 is a full frame figure so taking into account the 1.39x crop factor on the Super 35mm sensor the FS7 will have an angle of view of 39-187mm (35mm equivalent).

fs7-t

zoom-handle

The ability to zoom is built into the FS7 with this interesting servo zoom control, personally Sony have hit the right sweet spot by finally delivering a 4K camera that has a servo zoom facility. Far to many cameramen and women have avoided the large sensor market because the cameras take them well out of their comfort zone, having a servo zoom not only enhances the FS7 but allow it to be used in run and gun situations…a major bonus.

pxwfs7-no-lens

The no lens option is cheaper but is it value for money…

If you buy the camera with the lens it works out at £1550 more but buy the camera without a lens and purchase it at WEX it will cost you £2300 thats a whopping £750 more for the same lens.

Because of the Super 35mm sensor you have a far wider range of lenses and lens mounts for the FS7 lets look at some non servo alternatives.

ff

The first thing you need to consider is the crop factor (1.39)…if you buy a full frame (FF) lens like the Sony FE 24-70mm you will need to multiply the focal length by 1.39x for a 35mm equivalent…the FF 24-70mm will have a 35mm equivalent of 33-97mm.

The Sony E 16-70mm although made for an APS-C sensor still has a crop factor of 1.39.

CVP-crop-factor

This comparison chart from CVP explains how each sensor size has a different crop factor.

Multiply a lens’ focal length by a camera’s factor to get the focal length of a lens which, when used on a full-frame or 35mm film camera, gives the same angle of view as that lens does on that digital camera.

A 100mm lens on a 1.39x factor camera shows the same area of view that a 139mm lens would show on a 35mm film or full-frame camera.

Sony have completely confused the “E” marketplace with FF and APS-C lenses…why did Sony not make the A7 range of cameras “A” mount, this would have made far more sense and given A7 owners a far greater range of FF lenses.

MTF-v2

The Zeiss 35mm PL lens is still 35mm no matter what camera you mount it onto but the sensor size dictates the crop so on the FS7 (Crop 1.39 for a Super 35mm sensor) the 35mm prime lens will have a 35mm equivalent of 48mm.

The Sony PXW-FS7 will tick a lot of boxes including the servo zoom 28-135mm f4 lens, I am not so sure why Sony are insisting on bringing out so many constant aperture (CA) f4 lenses when they have a range of good CA f2.8 “A” mount lenses on offer though you will have to factor in a lens adapter and a 1.39x crop.

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7 comments on this post

  1. Jiri Vrozina says:

    I thought crop factor was x 1.5

    HDW : You and me both Jiri but CVP have the Super 35mm sensor as a x1.39 crop factor.

  2. Andrew Jones says:

    Jiri and HDW, it seems that SONY Japan are also of the same understanding.

    The Japanese SONY website also clearly state a 1.5x crop factor on their website. Therefore, HDW I would tentatively assume that you were right first time.

    This is the link to the 24 – 70 mm FE lens you use as an example. http://www.sony.jp/ichigan/products/SEL2470Z/feature_1.html

    In the list this is the part that specifically notes focal length:
    焦点距離イメージ(mm):36-105mm(*)

    The asterisk links to the following footnote.

    * 撮像素子がAPS-Cサイズのレンズ交換式デジタルカメラ装着時の35mm判換算値(mm)
    [Translation]: 35mm Focal length equivalent when using an APS-C size image pickup device (sic).

    CVP are not a company that is likely to make a conscious mistake on this so it is either a simple printing error or there is some other reason. If so, I am very interested to learn.

    HDW : Lensrentals has the Super 35mm sensor’s crop at x1.4

  3. Bernd says:

    Neither APS-C nor Super35 denote a certain size. It can always vary a few millimeters from manufacturer to manufacturer and from camera to camera, and APS-C (photo) is different from Super35 (video), too. So one should even expect that the crop factor of a lens is not the same on different cameras, and all of you may be right. Usually a Super35 camera should have a bit less crop than an APS-C camera, so something around 1.4x should be right for the FS7.
    BTW, to make things more confuse, on the German website Sony says that this 28-135mm lens will be “42-202,5mm when used with an APS-C or Super35 camera”. Unfortunately the website is notorious for being inaccurate sometimes, so I wouldn’t put too much trust in this information.
    I guess it doesn’t really matter here anyway if the shortest focal length is 39mm or 42mm because both are not what one want to have in a camera like the FS7. No wonder Sony is considering an additional wide-angle adaptor already but I hope we will see another lens with the same features but more wide angle in the future. The 28-135mm clearly is not well suited for a Super35 camera.

  4. inc says:

    Different Super 35 sensors are different sizes. They are not one in one with S35 film. FS7 sensor is actually smaller than the one in your CVP chart. Also if you record 4K crop ratio is smaller than when recording QHD and loosing some of the effective sensor size. 1.5 is probably lot more closer to correct crop ratio than 1.39. But again crop ratio will be different on QHD and 4K.

    What comes to this lens focal length confusion, I already mention this once but you chose not to publish it.. so commenting to your revised article now…

    ” I will assume the 28-135 is a full frame figure”
    “The Sony E 16-70mm although made for an APS-C sensor still has a crop factor of 1.39.”

    Even lenses made for APS-C still follow the same focal lengths crop ratios with FF lenses and you ALWAYS have to count in the camera crop ratio. 16mm lens made for FF is 24mm on 1.5 cropped camera. 16mm lens made for 1.5 cropped camera is still 24mm on that camera. Only difference is that if you put the later one on FF it will not cover 16mm image circle, only 24mm equivalent area within that 16mm and everything outside that will be black (as in seeing the lens barrel) or vignette very heavily. For ex. If you put Sigma 18-35 on 5D it will not cover the whole image circle unless you zoom in to 28mm

  5. Heidfirst says:

    Not sure that I agree that “Sony have completely confused the “E” marketplace with FF and APS-C lenses…” They do seem to have confused plenty of non regular Sony ILC-using reviewers though ;). The bodies are smart enough to auto-crop so that an APS-C lens on a FF body doesn’t vignette.
    As for “why did Sony not make the A7 range of cameras “A” mount, this would have made far more sense and given A7 owners a far greater range of FF lenses”.
    a) they are aiming for a size advantage over traditional DSLRs..
    b) whilst there are currently more A-mount FF lens many although very good>best in class are older (some basically can be traced back to 1986 designs), some are still screw-driven AF & they all have mechanical aperture control rather than electronic.
    c) you can still use A-mount FFs on E-mount via adaptor (even keeping AF)

  6. Mark Weiss says:

    The FS7 desparately needs a wider version og the 28-135 lens.
    the 18-105 that they’re selling is a consumer lens and not of the same quality.
    i’m told it’s impossible to make wider zooms for s35, but it’s already beibg done, however the lens is tiny DSLR with no manual rings that are proper for focusing and iris control.
    Sony, are you listening?

  7. de says:

    I’m very confused! Is that E 16-70 going to fill the Super 35mm sensor properly? Will it not be effectively 24mm which is just about wide enough to be practical? Or will it have dark edges as it is only APS-C size? Why is it that ALL Manufacturers hide this info so well!?

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