True! But tell me of the wide, fast ones that are good for astro. No, really, if I missed something, I want to know!
I don't think astro lenses for the RF mount are a priority for any of the manufacturers.
Upvote
0
Sigma: No plans to release RF full-frame lenses yet
- Thread starter Canon Rumors
- Start date
True! But tell me of the wide, fast ones that are good for astro. No, really, if I missed something, I want to know!
I don't think astro lenses for the RF mount are a priority for any of the manufacturers.
I'm afraid I'm not familiar with that style of shooting but browsing the listings on Wex I see a Laowa 10mm f2.8 Zero-D, Laowa 4mm f2.8 Circular Fisheye, Laowa 12mm f2.8 Zero-D, 15mm f2 Zero-D, Samyang 14mm f/2.8, TTArtisan 10mm f2, Laowa Argus 28mm f1.2, TTArtisan 21mm f/1.5, TTArtisan 11mm f/2.8, amongst others - I have no idea if any are suitable but there are a fair few wide/wide lenses (depending on your parameters) out there now.
Upvote
0
Yes, but the difference in flange distance is most relevant for wide angle lenses, which indeed can be more compact (the RF 10-20mm versus the EF 11-24mm is an example). The difference in flange distance does not have a significant impact on the size for tele lenses like the 100-400mm.
Upvote
0
I am not convinced about that. If it were true then why didn't Canon make a smaller 100-400 years ago? I think there are aspects of the RF mount that we're ignorant to that make it possible for smaller lenses (of all focal lengths) than with EF.
I don't know how easy it will be for Sigma/Tamron to do RF lenses that are straight conversions of the other mounts as the RF diameter is the biggest of the 3.
Upvote
0
Maybe not all of us. In the case of longer lenses, what makes smaller lenses possible is not the mount but the autofocus system. DSLRs used dedicated phase-detect AF sensors that required a max aperture of f/5.6 (though 3rd parties fudged that by 1/3-stop, and the last round of better DSLRs could focus at f/8 with a very limited number of AF points; Canon stated that was for TC use because EF lenses needed to work on all their DSLRs).
MILCs focus with the image sensor and don’t require that maximum aperture. Thus for mirrorless we have smaller telephoto lenses like the 100-400mm f/5.6-8 and 800mm f/11, which were not possible for DSLRs.
Upvote
0
No offense meant, yet I wonder if you find the affordable RF 1,8/50 unaffordable, how can even you afford a camera body?
$150 is no lunar price for a 50mm lens...
That wasn't in my thoughts when I wrote.
Upvote
0
Halving the light is quite the tradeoff to go from 70-300 f/4-5.6 to 100-400 f/5.6-8. ISO and IS only makeup some of that.
Lenses such as the optically excellent 70-200 f/4 IS USM seem to be forgotten relics of history now.
It will be interesting to see how the new RF 70-200/2.8 (internal zoom) compares in weight and size to its EF cousins.
Upvote
0
Also, what you posted there is a fallacy. With a telephoto lens, photons gathered are proportional to the iris diaphragm diameter. Divide 300 by 5.6 and divide 400 by 8, and the difference between those two quotients is the light lost. Hint for the mathematically challenged: it’s almost none.
This ‘issue’ has been well-covered in comparing the EF 100-400 at 400/5.6 with the RF 100-500 at 500/7.1. If you’re interested in the math behind this concept, it’s explained well by @AlanF here.
Upvote
0
Thanks for joining last Saturday.... I can't seem to understand where you are coming from with the comments though...
You seem to dislike the RF lenses and want to compare to EF lenses although the last released EF was a long time ago albeit glass works for a long time. All EF lenses can be adapted to R mount and there are ~10 R mount (supporting RF and RF-S lenses) bodies in the market covering a very wide range of price points and performance.
R mount and RF lens protocols provide a lot of advantages over EF. Virtually all RF lenses released have some advantage over their closest EF counterpart or have been unique lenses in their arsenal. Canon have a cheaper lenses and expensive lenses but it could be argued that they are missing some obvious mid priced ones eg 50/1.4. Canon certainly has some price premiums offerings but this seems commercially reasonable to amortise R&D and limited production capacity.
What are you shooting with now and what do you need for the future?
Upvote
0
You have missed the mistake I made and that is while a full stop difference on a given lens does halve the light reaching the sensor, you can't use the same mechanism between different lenses.
Using the math you suggested, for the point of comparing, what matters is the f-stop of the 100-400 at 300mm, which isn't going to be 5.6 on the RF lens, lets say 7.1.
300/5.6 is ~53
300/7.1 is ~ 43
So about 20% loss but that's using a guesstimate for the f-stop on the 100-400
Upvote
0
Sorry, I missed that. Curious. Was the 100-400 designed to be capable of putting on DSLRs?
I wonder if Sigma will go back to the drawing board for mirrorless lenses now that there are no mirror box cameras to design for.
Upvote
0
I see. In fact, the RF 100-400 is f/8 from 259mm on, so it is a full stop. But they’re different lenses anyway. One lacks the 70-100mm range, the other lacks the 300-400mm range. I expect Canon felt more people wanted an inexpensive 100-400 than a 70-300, which makes sense because there are already lenses covering 70-100mm, but there were no non-L zooms going beyond 300mm.
The beauty is that if you only want 70-300mm, you can simply adapt the EF version. But then…the RF version is cheaper.
Upvote
0
Well it really depends on the lens! The RF10-20/4 is much cheaper/smaller (better?!) than the EF11-24/4. The RF100-400 is remarkable for the value for money. Let's not forget the RF600/800 f11 and RF200-800 allowing new users into rarefied supertele territory for the first time
No one likes higher prices but when you get better value for money (however you define it) then they are generally reasonable (RF600/4, RF800/5.6 aside).
No one is forcing anyone to give up their EF lenses either. I have one more to migrate at some point but it will give me an extra 2mm at the wide end meaning my EF8-15/4 is less likely to be needed in the future. Their strategy has enabled me to migrate at my own pace over 4 years now.
One lens (50/1.4) doesn't make Canon's strategy wrong but it is strange.
You haven't answered my main question though... let's have some context to your points...
If not, then a rant into a vacuum is what it is.
Upvote
0
Yes, where the f-stop changes in zooms is not widely published.
All depends on what you pair it up with, either the 24-70 or 24-105. The EF 24-105s were not that great (compared to the 24-70), so once bitten, twice shy.
Hopefully Sigma & Tamron will pick that up like they did before with the various 150-600s. Time will tell.
Upvote
0
Similar threads
