Sony SAL 1650- Parfocal? For sure?

BrianMurphy

BrianMurphy

Veteran
I recently checked out Shawn Lam's shootout and review of the Sony SAL 1650 lens. His experience along with several other googled results say the lens is parfocal. A friend recently bought this lens and found it not to be parfocal or at least the one he had did not keep focus so he returned it. Perhaps it was just a defective lens but it turned him off on getting another.
Has anyone else experienced this problem? I am about to buy my camera this week and along with the kit lens I ordered the SAL 1650 as a lens for convenience. I have a collection of primes but don't always want to travel with them and thought this would be a good option.
Thanks
 
In my experience with 3 different SAL 1650 lenses on my FS100 they are NOT parfocal. Its a shame and inconvenient but not enough to turn me off the lens entirely. Its still very useful so I just nudge the focus a bit when I zoom. Compromises, compromises...

Ian
 
Ian thanks for the info and the post! I think I will hold off on the lens in this case and just go with the kit and my existing glass for now until we see what the new firmware and the LA-EA2 has to offer.
Cheers
Brian
 
Are you both positive that you are checking the parfocal nature correctly? I've had 3,000 people visit that page and I haven't heard any user experiences saying that their lenses are not parfocal, except for those that are testing incorrectly.

A parfocal lens will hold focus when you manually focus on a subject at full telephoto and then zoom out. The subject will stay in focus at all focal lengths. So you can zoom back in and then back out and the subject will always be in focus.

The same is not true when you manually focus at wide and then zoom in.

The reason is that the depth of field (area that is in focus) is greater (bigger) when you are wide but becomes shallower (less is in focus) when you zoom in. So you have to set your manual focus settings for when your depth of field is the shallowest, which is at full telephoto.

@ IanD - can you retest and reconfirm.
 
mine is not parfocal so i whent and buy the old tokina atx pro 28-70 witch may not be perfect but way better than the sal1650
 
I retested the Sal 1650 and got the same results. This lens does not hold focus during a zoom. The old zoom in, focus and zoom out does not work for this lens necessarily. Its not off by much, especially at higher f stops but it doesnt hold perfect focus. Test for yourself: using the expanded focus function zoom in and focus on your subject, ideally close to minimum focus. Now zoom out and check focus whole still in expanded focus mode. You will most likely need to slightly adjust the focus a touch closer. If you are shooting at higher f stops it may not make any difference to you as it will still be in acceptable focus due to dof but for critical focus an adjustment has to be made. Thats my experience with my SAL 1650 your milage may vary.
 
Gary W said:
How smooth does it operate?
Click to expand...
The focus and zoom are reasonable smooth but not buttery smooth like a nice manual focus Canon Fd or Cine lens. Its kind of a dry action but no slop or bumps. I personally liked the action on my Tokina 16-50 better, especially the zoom dampening but the SAL 1650 is not too bad.
 
On a consumer zoom lens, one is going to find perfect parfocal zoom samples hard to find - even though it may have been designed to be parfocal.
Even on professional zooms, one has to constantly adjust and check the backfocus in order to maintain perfect parfocal focus. Consumer zooms / cameras don't have that ability.
 
IanD said:
I retested the Sal 1650 and got the same results. This lens does not hold focus during a zoom. The old zoom in, focus and zoom out does not work for this lens necessarily. Its not off by much, especially at higher f stops but it doesnt hold perfect focus. Test for yourself: using the expanded focus function zoom in and focus on your subject, ideally close to minimum focus. Now zoom out and check focus whole still in expanded focus mode. You will most likely need to slightly adjust the focus a touch closer. If you are shooting at higher f stops it may not make any difference to you as it will still be in acceptable focus due to dof but for critical focus an adjustment has to be made. Thats my experience with my SAL 1650 your milage may vary.
Click to expand...

That's interesting. I tried the zoom in, focus and zoom out method and found my lens to be parafocal. I used this method to shoot a few subjects, and it seemed to work just fine. However, when shooting, I had the f-stop set to F 4.0. I have not done a shooting test with the aperture wide open. From looking at the LCD screen even with expanded focus on, the focus appears to remain throughout the zoom range, but it is hard to tell on such a small screen. Maybe when the firmware update comes out and allows 8X expanded focus I will be able to tell. As far as the zooming and focus action goes, I agree that it is not as nice as the Canon FD lenses.
 
In my testing, I used an HD monitor and checked the results in Premiere Pro CS5.5 at 400% magnification to confirm the parfocal nature.

For those of you that haven't seen my simple parfocal test on the SAL1650, it is in this blog post. I also tested two other lenses in the same test. All the tests were done at f/2.8.

http://www.shawnlam.ca/2011/sony-sal1650-on-nex-fs100/
 
ShawnLam said:
In my testing, I used an HD monitor and checked the results in Premiere Pro CS5.5 at 400% magnification to confirm the parfocal nature.

For those of you that haven't seen my simple parfocal test on the SAL1650, it is in this blog post. I also tested two other lenses in the same test. All the tests were done at f/2.8.

http://www.shawnlam.ca/2011/sony-sal1650-on-nex-fs100/
Click to expand...

Shawn, I bought a SAL1650 after viewing your test.


The lens I bought must have been a lemon, using a lens chart and my 17" Panasonic HD Monitor… it clearly didn't hold focus.
When I returned the lens, the salesperson and I tested a 2nd… It was better but not parfocal.
Sony Canada must have released a batch which didn't meet specifications.


It's the kit lens with the a77… so I plan on testing a 3rd lens after the a77 is available in Montreal.


In the meantime, I've ordered a Sony Carl Zeiss Vario-Sonnar 24-70mm f/2.8
A friend is using one on a doc… and loves it.
 
Not sure if I can get my hands on the Tokina 50-135mm f/2.8 but it does sound like a great lens. It is only available in Canon and Nikon mounts and doesn't have an aperture ring. It is also reported to be parfocal and is an internal zoom.
 
Hi Shawm,
After reading your blog, I got the minolta 70-210 f4 from ebay. My son insisted that I should instead get the minolta 80-200 f2.8 as it's the ultimate minolta lens. I did too. I plan to sell one of them after I do tests. Should I get the SAL 1650 for my wide to med zoom needs? I already have the kit lens to cover this. What do you think?
I also bought the LA-EA2 adaptor but it's just a dumb adaptor without the firmware update. Any news when this will be released?
Thanks for your advice.
 
Hey Eric,
The 80-200 f/2.8 is very nice. I've been thinking a lot about a telephoto lenses that are faster than f/4.0. I'm not really sure it would be the best use of my money to upgrade my beercan 70-210 f/4 to one. The big reason is that the depth of field at f/4 and zoomed all the way in is shallow enough and f/2.8 might be too shallow to be useful on the type of work I do. If you can't get the nose and ear in focus on a shot, that is a good sign your depth of field is too shallow.

I still like the SAL1650 but another lens that has caught my attention is the Sigma 17-50 f/2.8 EX DC OS HSM lens. While it isn't parfocal, it does have image stabilization in-lens. Paired with the LA-EA2 adapter, with the new firmware due out in March, you also get Autofocus and smooth iris adjustments. There are only a few combinations that will give you IS, PDAF, and smooth iris.

I'm more interested in IS on a wide lens because those are the ones I am more likely to use hand-held or on a shoulder brace, while the long lenses on this body are for use on tripods only and you would turn off the IS on the tripod anyways.

The other popular range is 28-70 (some are 24 on the wide end and others 75 on the long end). But I like the wider 16/17-50 better as wide is harder to get and for the missing 51-69mm range between my SAL1650 and beercan, I can usually just move my position to or fro, although I do have some glass in that range that I'm not completely happy with but keep just in case I need it.
 
B&H just emailed that they have shipped my order

2ea LA-EA2's
SAL 16-50 2.8
SAL 28-75 2.8

Maybe do a little review myself before and after the firmware upgrade (if it ever comes.....)
 
videohog said:
B&H just emailed that they have shipped my order

2ea LA-EA2's
SAL 16-50 2.8
SAL 28-75 2.8

Maybe do a little review myself before and after the firmware upgrade (if it ever comes.....)
Click to expand...

Out of curiosity why 2 LA-EA2s?

This is one of the possible routes for me too, i will try the canon lenses (with the electronic adapter first) and then ponder whether it would be better for me to move everything over to sony/zeiss lenses. I look forward to hearing how they are for you - specifically with Manual Focus

cheers
Paul
 
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