Trying to decide between two lenses...

[dirk]

Here's my calculation...

The field of view is inversely proportional to the focal length, so the crop factor is just 40/35:

• 40/35 = 1.143

Since crop factor is about linear dimensions, we need to square it get to the area crop.

• 1.143 x 1.143 = 1.307

So, the reduction in Mp is:

• 24/1.307 = 18.4Mp

So, the % loss is:

• (24-18.4)/24 = 23%

If I do this calculation for my S1Rii with the 35mm and 40mm crop, this would reduce then the MP from 44MP to 33,66MP. That would be a very good "deal" in my view.

 

[dirk]

Then, I need to decide, which of the two primes ... 35, and crop... or, 45mm.
I'll do some trial with zoom lens set to 45mm, and see, what happens.

Image quality of the 35mm is better.

 

[Babylonia]

Image quality of the 35mm is better.

I have no comparison by a 45mm lens.
But the SIGMA 35mm F2 DG DN | Contemporary really is very good.
47 megapixel Panasonic S1R - Full wide open F2.0 - 1/200 sec - ISO 100

Full image area - resized to 1600 pixels wide

• Panasonic - DC-S1R
• Sigma 35mm F2 DG DN | C (L-Mount)
• 35.0 mm
• ƒ/2
• 1/200 sec
• Pattern
• Manual exposure
• 0.3
• ISO 100

Image at 100% and cropped area 1600 pixels high

• Panasonic - DC-S1R
• Sigma 35mm F2 DG DN | C (L-Mount)
• 35.0 mm
• ƒ/2
• 1/200 sec
• Pattern
• Manual exposure
• 0.3
• ISO 100

Image at 100% and cropped area 1600 pixels high

• Panasonic - DC-S1R
• Sigma 35mm F2 DG DN | C (L-Mount)
• 35.0 mm
• ƒ/2
• 1/200 sec
• Pattern
• Manual exposure
• 0.3
• ISO 100

Even with a 24-megapixel camera, I think you have enough spare to digitally crop a 35mm lens to an angle of view equivalent to a 40mm lens.
-

 

[TOPSHELFJR.]

A couple of months ago I was in the same situation. I decided for the Sigma 70-200/2.8 sports DG DN and never regretted it.

The deciding factor for me was size, weight, price and the fact that a lens with sports in the name might be better in the AF for sports photography, which is the main (or only) use case for me for this lens.

The Sigma has a very good image quality even on the S1R2 and the AF dies not disappoint with erratic spirts (field hockey). When I am back from travelling, I will post some expamples.

Nice !!! Love hearing this. Looking forward to the images later. Talk soon ! Thx !

 

[TOPSHELFJR.]

There are also more "practical" reasons to consider that can have a bigger impact in real life than only comparison of optical qualities.

A choice also can depend on other zoom lenses you are using already. (E.g. owning a Sigma or Panasonic 24-70 mm zoomlens ?)
As e.g. the rotation of the zoom ring from wide-angle to telephoto is the opposite direction for the Sigma and Panasonic brand.
So changing from one zoom-lens brand to the other - and using Sigma as well Panasonic.
You definitely will make mistakes zooming in and out, which direction to turn the zoomring.

Panasonic having a bayonet type of hood.
Sigma you have to slide the lens hood to the lens, and clamp it with a screw on the side.

Taking off the tripod feet:


But the Panasonic lens is much more heavy, than the Sigma lens.

Hmmmmm, nice point about the tripod extension, something to think about for sure. And thanks for sharing the YT video, his visual explanation was clutch. Thx !

 

[TOPSHELFJR.]

I own the Pana 70-200 f2.8. It's a beast of a lens in terms of quality, performance and build quality. On the other site for a 70-200 f2.8 in the mirrorless world it must be one of the biggest and heaviest ever.
I got it when there was no tele option for more then 200mm and it works with the 2x TC very well.

Today, I would go with the Sigma 70-200 f2.8 instead. It's fast, sharp, image quality is superb, ligher, cheaper and made in Japan.

I did not check this, but with a little bit luck it might be compatible with em the Sigma TC's 1.4 and 2.0. Both are excellent TC's.

Thanks for the taking the time to share this !!! Very very interesting, and I'm kind of pleased to hear that about the Sigma, being comparable in terms of image + quality. I think subconsciously I'm leaning towards the Sigma, just because if I can spend less...why not ! lol. Thanks for your feedback.

 

[Miki]

Even with a 24-megapixel camera, I think you have enough spare to digitally crop a 35mm lens to an angle of view equivalent to a 40mm lens.

Normally, 50%.
It can be doubled by using Super Resolution tool in PS.

 

[Jonathan-Mac]

Some months ago there was this rumor:

New 7Artisans AF 40mm f/2.5 FF lens makes its debut at the NAB show - Photo Rumors

At the 2025 NAB show, 7Artisans unveiled a new 40mm f/2.5 full-frame autofocus lens: Check the official 7artisans website for updates. Sony and Viltros both already have 40mm f/2.5 lenses. All new product announcements from the 2025 NAB show can be found on this page. The new 7Artisans lens was...

photorumors.com

I am still waiting for that 7artisans Lens.

Another option is to get the Sigma 35mm f/2 DG DN Contemporary and activate the crop zoom on your camera (If you have a S9, S5II/X, S1ii, S1iie or S1Rii), leaving the focal length at 40mm...

Yes, I'm also still waiting for the 40mm f/2.5 and if it ever appears I'll likely buy it immediately as long as initial reviews are good.

The Sigma 35mm f/2 is superb, and the Canon 40/2.8 with adapter pretty good too, I just want an option that's smaller and native.