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Sony a7RII compared to XF / IQ3100

Somewhat surprisingly, it seems that the IQ3100 has close to 15 EV of DR (per pixel), quite impressive.
We get conflicting results everywhere and I suspect that temperature has a significant impact on this.

BartvanderWolf at lula measured 14.39 EV, while I measured something slightly above 14 EV.

There's a site called "" (the Chinese equivalence of According to their review, the IQ3100 has less DR than D810 does at pixel level, and this is prominent for long exposure of 30s. The IQ3100 needs to downsample to show its advantage of DR over the D810. (The last plot attached here is the "effective number of megapixels remaining to achieve 40dB SNR for shadow after downsampling".)




Bryan Stephens

Workshop Member
I can only comment on how the a7rII compares to my lowly IQ3 80 and to me there is absolutely no comparison, especially if you are looking for large prints and fine detail. The amount of information that is captured by the IQ back is immense and allows for a bit more range for post processing.

That being said, if you are looking to travel light, the a7rII is an excellent choice as this is my go to system when I am taking a business trip, and cannot take my phase kit with me. I like it so much that I ended up selling off my entire Canon and Nikon systems (also I dont shoot fast action sports as much any longer). My favorite lenses are the Canon 24 TSE, my Zeiss 25 batis, and my Canon 16-35 2.8. I also carry the FE 24-70. The funny thing is that those 4 lenses weigh about the same as my Phase 35mm BR

Bill Caulfeild-Browne

Well-known member
I appreciate the input, but comparing these two camera systems is nonsensical, imo. I think the Sony A7R2 is rather remarkable to be held to such a high standard and considerably more cost efficient. Unless your printing extreme sizes I doubt most will notice the difference...unless you're shooting video:)
As the French would say, chacun a son gout. I can see the difference in tonality and DR in a 16 by 20. I agree absolutely the Sony is outstanding (that's why I have one) and with some subjects and reasonable size prints, probably just as good as the Phase. But as a general rule the Phase files are simply better - to my taste - than the Sony. And if you need to crop significantly then there is no contest.

Value for money - Sony wins easily, just as a Chevy is way better value for money than a Porsche. But which delivers higher performance?

Ed Hurst

Well-known member
I'm using the Sky-Watcher Star Adventurer. It has an 11 pound capacity and handles the XF + 35 LS OK but you do have to be sure everything is tightened since the clutch can slip if it's not tight and you have an eccentric load. You obviously don't have to be as careful with the Sony since it's so much lighter.
Thanks for sharing the info.. So presumably the star shots you showed are composites of tracked images and non-tracked images for the static foreground scene? If so, nice work in the blending!

Craig Stocks

Well-known member
No, the star shots are not tracked. Since I was restricted on weight I didn't bring the tracking gear. They are usually 10 to 15 seconds at 14mm 0r 24mm and ISO 2400 to 3200. I'm curious to get more head to head comparisons this spring and summer since astro landscapes seems to be an area where the Sony excels. My limited experience is leading me to believe the Sony does better with tones where the Phase is sharper.