First impressions on full-spectrum Sony Alpha 7II (7 II, ILCE-7M2)

[enricosavazzi]

I am not completely sure whether the Sony Alpha 7 II has been discussed before. The search function of this site refuses to deal with one- or two-letter strings, so I may have missed something. The text in parentheses in the post title might make future searches easier.

 

My first impressions of the camera as converted by infraredcameraconversions.com (spoiler alert: very positive):

http://www.savazzi.n...llspectrum.html

[Andy Perrin]

Sounds like a very nice camera! I love my Sony A7S. I have not observed any dust caught under the glass in my conversion, and to be honest I accumulate dust above the glass at such an inconveniently high rate that on most occasions it would be hard to tell the difference. But it was clean when it arrived from LifePixel (the second time...). And PS's content-aware fill fixes the rest.

 

Since the image is 6,000 by 4,000 pixels, no current monitor is capable of displaying the entire image at full resolution, and printing on paper at any reasonable size does not show this problem. This problem is therefore mainly of theoretical interest, and if desired can be reduced by software smoothing/blurring with kernels of small diameter.

 

While the overall thrust of this comment is probably true most of the time, it is not true that no current monitor is capable of displaying the image at full resolution. Technology marches on! Dell, for example, has an "8K" monitor with a native resolution of 7680 x 4320.

[Shane]

Not knowing anything about Sony or Olympus digital cameras - can the Alpha 7R, R II and R III, or Alpha 7, 7II and 7III, or the OM-D E-M1 MkII, accept a UniWB and is it possible to upload custom built Tone Curves?

[enricosavazzi]

Not knowing anything about Sony or Olympus digital cameras - can the Alpha 7R, R II and R III, or Alpha 7, 7II and 7III, or the OM-D E-M1 MkII, accept a UniWB and is it possible to upload custom built Tone Curves?

I have not done any of these things, and don't know whether it can be done in-camera. I don't see any settings to that effect in the menus of the Alpha 7 II. The only operation that can be done with CWB is take a new CWB by shooting a target, and select to which of the three CWB memories to save it.

 

White Balance Adjustment (not displayed in the menus, I learned about it in David Busch's book), lets you fine-tune the current WB setting in-camera in a square diagram where the vertical axis is green/magenta bias and the horizontal axis is blue/amber bias. Only 15 steps are possible in the vertical and horizontal direction in the diagram, so for example the top left corner of the diagram is B=7, G=7 (which is as green as it goes) and the bottom right corner is A=7, M=7 (which is as magenta as it goes). My CWB with the Baader U filter for example is A=0, G=7 in this diagram, so already at the top edge of the diagram in the green/magenta dimension but at the center of the range along the blue/amber dimension (so I could shift it 7 steps either toward green or toward yellow).

 

It is also possible to enter a WB in degrees Kelvin (in steps of 100 K) but in this case the adjustment with the square diagram is not available.

 

However, by saving in raw format one can apply any white balance in post-processing.

[Shane]

Thanks Enrico.

However, by saving in raw format one can apply any white balance in post-processing.

As always, I use UniWB to make the histogram better represent RAW data, rather than jpg, for maximizing and evaluating exposure. Post WB correction, although useful to many photographers, does not help my process.

[dabateman]

Enrico,

What I find interesting is that they changed the IR shutter monitor to make this camera usable. I didn't know of any companies doing that.

 

Shane,

I found this link for UniWB with Olympus:

 

https://www.dpreview.com/forums/post/41245342

 

I have never done that.

 

[enricosavazzi]

Enrico,

What I find interesting is that they changed the IR shutter monitor to make this camera usable. I didn't know of any companies doing that.

[...]

I don't know the details of how they did it at infraredcameraconversions.com for my camera, but I saw somewhere on the web a description of how someone replaced the NIR LED with one that emits at a longer wavelength, and possibly also the photodiode with one sensitive to longer wavelengths. I did not keep the link. Any LED that emits at around 1,500 nm or higher wavelengths is probably safe to use.

[dabateman]

Enrico,

Nick spiker talked about it here:

https://www.nickspiker.com/blog/search-digital-kodak-aerochrome/

 

I think that was the first time I saw someone do the modification. But there are probably others now.

 

Also not to totally derail this thread. But more on Shane's question. For the Olympus cameras the answer is yes for UniWB. But it seems interesting depending on the model. The Em5 seems to have odd red and blue channels, so when implemented the preview is extremely green. The Em1 was reported to better balance the red channel. This seemed to be a hot topic in 2013. But then later, people liked the colors directly out of camera and moved away from UniWB. I actually hadn't heard of the UniWB used in Olympus cameras until you asked. Most Olympus fans go on and on about the "colours" SOOC and don't mess with that stuff. Also maybe ETTR isn't as popular as it once was. Cameras made in 2013 and after seem to do everything well. Prior to that we really needed to push the DR.

[Shane]

I found this link for UniWB with Olympus:

Thanks

[enricosavazzi]

Enrico,

Nick spiker talked about it here:

https://www.nickspik...dak-aerochrome/

[...]

Yes, that is most likely the page I saw.

[Timber]

I have my A7II collecting dust at home... the LCD is gone for more than a year and the Play button does not work since my last Skye trip :) But the camera is still operational and delivers amazing results (but having the A7III as well, I don't use it too often)... I might get it converted... just not sure if I should send it to Sony for repairs before... Might be better off just buying a converted camera :)

 

Do you know what is he using for the conversion? My NEX-6 has the Spectrosil 2000 silica and the UV capabilities are quite good.

[dabateman]

Timber,

From what I understand, nothing. As in the sensor is moved closer to the flange mount to regain infinity focus.

This can work depending on the lenses you use.

[enricosavazzi]

Timber,

From what I understand, nothing. As in the sensor is moved closer to the flange mount to regain infinity focus.

This can work depending on the lenses you use.

Exactly, this is what I call a "remove-and-recalibrate" conversion. The UV- and IR-cut window and anti-aliasing filters are only removed, not replaced. Then the registration distance is adjusted. In principle this will work with all lenses. If they could focus at infinity before conversion, they should do so after conversion. Unusually fast lenses might not work optimally, but we rarely use these.

 

I have a few thoughts about the two different conversion methods at the link in my original post.

[Timber]

Wouldn't it make the sensor more fragile?

[enricosavazzi]

It is fragile in the sense that, should you scratch the built-in window of the sensor package, there is no way to fix it, short of replacing the sensor package.

 

If conversion is done by replacing the UV+IR cut filter etc. with a silica glass window, if you scratch this window you still need to replace it (but in principle can keep the original sensor package). However, how often does this happen? And in any case, the cost of replacing the window is the same as converting a stock camera to full-spectrum.

 

The built-in filter of stock cameras is vulnerable to scratches, too, so all of the three alternatives (i.e. unmodified, remove-and-replace, remove-and-recalibrate) are equally vulnerable. When the built-in filter of a stock camera is scratched, the usual way of repairing it is by replacing the whole sensor package, instead of just replacing the filter, because this is the only sure way to prevent trapped dust between filter and sensor.

[Timber]

how about wet cleaning? Is it safe with the remove-recalibrate process? (I just received my A7II modded by Alan this way)

 

so far my experience with the camera is very positive... the camera can handle ISO1600 easily, it's a HUGE step up from my old Nex-6 :)

[enricosavazzi]

I generally set the camera to auto-ISO with max at 1600, or leave it at manual ISO 1600. It seems a fully satisfying "base ISO" for UV imaging with this camera. I only go down to 200 or 400 ISO for the VIS control images, to avoid using an ND filter to compensate for the much higher sensitivity in VIS.

 

I have not tried wet cleaning (or any cleaning other than a rubber blower), but I should assume that any cleaning method that is safe for the built-in filter will also be safe for the "naked" sensor package window.

[Andrea B.]

Editor's Note: Yes, the search engine is bad. Using the UV Camera tag is probably the best way to search for Sony conversions. I added one to Enrico's initial post in this topic.

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