Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-14-2019, 11:39 PM   #1
Site Supporter
Site Supporter




Join Date: May 2019
Posts: 28
Sigma 17-50 and 17-70 with flash question

Im looking into getting one of these and I use my built in flash alot on my K-50 and im wondering if either of these lens cause a shadow when use the popup flash? I know the Sigma 18-35 did, so id like see if I can get answer before I buy one so I can save myself time/money if it won't suit my needs. Thanks!

12-15-2019, 01:11 AM   #2
Forum Member




Join Date: Feb 2016
Posts: 70
The Tamron 17-50 causes a shadow when used with a k-5.

Although this can be minimized if you remove the hood.

I assume these dimension numbers are valid.

Sigma: 91.8mm x 83.5mm / 3.6 in. x 3.3 in

Tamron: 2.9 x 3.2" (74 x 82mm)

Side by side if you scroll down
https://www.the-digital-picture.com/Reviews/Tamron-17-50mm-f-2.8-XR-Di-II-Lens-Review.aspx

Last edited by krazny; 12-15-2019 at 01:19 AM.
12-15-2019, 01:35 AM   #3
Site Supporter
Site Supporter




Join Date: May 2019
Posts: 28
Original Poster
QuoteOriginally posted by krazny Quote
The Tamron 17-50 causes a shadow when used with a k-5.

Although this can be minimized if you remove the hood.

I assume these dimension numbers are valid.

Sigma: 91.8mm x 83.5mm / 3.6 in. x 3.3 in

Tamron: 2.9 x 3.2" (74 x 82mm)

Side by side if you scroll down
Tamron SP AF 17-50mm f/2.8 XR Di II LD IF Lens Review
Thanks for the info, I was afraid that would be the case due to the length or the wide filter size.
12-15-2019, 04:48 AM - 1 Like   #4
Site Supporter
Site Supporter
ramseybuckeye's Avatar

Join Date: Apr 2009
Location: Hampstead, NC
Photos: Gallery | Albums
Posts: 11,312
Yes, The Sigma 17-50 will block part of the built on flash on the K -50, donít know about the 17-70.

12-15-2019, 07:53 AM - 1 Like   #5
Loyal Site Supporter
Loyal Site Supporter
mhoule418's Avatar

Join Date: Jan 2013
Location: Quebec city
Posts: 140
The Sigma 17-70 will also show some shadow when used with the built in flash.
12-15-2019, 08:21 AM   #6
Pentaxian
35mmfilmfan's Avatar

Join Date: Oct 2016
Location: Norfolk, UK
Posts: 1,242
Isn't the answer not to use the pop-up flash ? A separate shoe-mounted flash should be usable with most lenses, in bounce mode.
12-15-2019, 10:10 AM - 1 Like   #7
Pentaxian
Kozlok's Avatar

Join Date: Jun 2012
Location: Albuquerque
Photos: Gallery
Posts: 2,857
It will be less than the 18-35, but if you use flash you will want a hot shoe mounted one.
12-15-2019, 10:43 AM   #8
Site Supporter
Site Supporter




Join Date: May 2019
Posts: 28
Original Poster
QuoteOriginally posted by 35mmfilmfan Quote
Isn't the answer not to use the pop-up flash ? A separate shoe-mounted flash should be usable with most lenses, in bounce mode.
Yes but I prefer to keep my camera bag light and I don't like camera getting supper heavy either. Weight is a major factor for me, if my camera gets to heavy I don't take as good of handheld shots than if my setup stays under 1000 grams or so.

12-15-2019, 11:12 AM   #9
Loyal Site Supporter
Loyal Site Supporter
mhoule418's Avatar

Join Date: Jan 2013
Location: Quebec city
Posts: 140
Pentax AF 200FG

QuoteOriginally posted by Tudor97 Quote
if my camera gets to heavy I don't take as good of handheld shots
The picture might not be good either because there is shadow created by the lens hood!

Also consider the lens weight... For sure the Sigma 17-70 is not small.
My preferred kit is : K-3 or K-5ii (with battery grip) + Sigma 17-70, so adding a small flash is just increasing the weight, but it balances well (for me).

The Pentax AF 200FG may be a very good option to consider :
  • small and not too heavy
  • cheap
  • bring more power than the built-in unit
12-15-2019, 02:21 PM   #10
Senior Member




Join Date: Apr 2012
Location: Endeavour Hills, Victoria, Australia
Photos: Gallery
Posts: 100
QuoteOriginally posted by Tudor97 Quote
Im looking into getting one of these and I use my built in flash alot on my K-50 and im wondering if either of these lens cause a shadow when use the popup flash? I know the Sigma 18-35 did, so id like see if I can get answer before I buy one so I can save myself time/money if it won't suit my needs. Thanks!
I'm interested in another aspect of this question (Also using Pentax k5). By using a Sigma lens, is it true to say that some of the functions of an external Pentax flash will be not available? I've noticed that when using a Sigma 18-200 lens with a Pentax flash the results are far from consistent. Exposures will vary quite a lot. I have noticed that when using the Pentax 18-55 lens that all of a sudden the results when using the Pentax lens give perfect exposures almost all of the time
12-15-2019, 02:55 PM   #11
Pentaxian




Join Date: Dec 2016
Location: Southeastern Michigan
Posts: 2,392
QuoteOriginally posted by peggers Quote
I'm interested in another aspect of this question (Also using Pentax k5). By using a Sigma lens, is it true to say that some of the functions of an external Pentax flash will be not available? I've noticed that when using a Sigma 18-200 lens with a Pentax flash the results are far from consistent. Exposures will vary quite a lot. I have noticed that when using the Pentax 18-55 lens that all of a sudden the results when using the Pentax lens give perfect exposures almost all of the time
As to the shadow from the built-in flash, this is because the size of the lens is causing it to be partially in the way of the flash output. Pentax does make a neat little hot shoe flash that has WR construction, and is not costly. It is so small it can easily be carried in a jacket pocket or takes up very little room in a camera bag. It also has more power than any bill-in flash of my acquaintance. But if the photography is takingrlce outside in bright daylight, and only some fill-flash is needed, there will probably be no detectable shadow from just the regular built-in flash.

The above is an interesting question. Indeed, lenses do feed info back to the camera, and some 3rd party lenses might be somewhat deficient in this regard. OTOH, I have numerous lenses by Pentax and 3rd party, yet have not noticed a discrepancy. Not to say it doesn't exist. But one thing the flash system is supposed to do is modify its flash angle according to the FL of the lens, yet there is a limitation for this. 55mm is well within that limitation, but a FL far greater, certainly 200mm, will not be reached, so the flash output will be more dissipated beyond the framing.
12-15-2019, 04:37 PM   #12
Loyal Site Supporter
Loyal Site Supporter
mhoule418's Avatar

Join Date: Jan 2013
Location: Quebec city
Posts: 140
Too far subject?

QuoteOriginally posted by peggers Quote
I've noticed that when using a Sigma 18-200 lens with a Pentax flash the results are far from consistent. Exposures will vary quite a lot. I have noticed that when using the Pentax 18-55 lens that all of a sudden the results when using the Pentax lens give perfect exposures almost all of the time
Well, not being an expert using flash, I suspect your problem is the “far subject” distance. When used at 200mm, the light produced by your flash is probably not reaching the subject, so “inconsistency” may be observed.

I may be wrong, but this is my though.

Edit
Oups! I stopped reading after peggers’s comment.
mikesbikes just said it too.

Last edited by mhoule418; 12-15-2019 at 04:47 PM. Reason: Info.
12-15-2019, 04:39 PM   #13
Site Supporter
Site Supporter




Join Date: May 2019
Posts: 28
Original Poster
QuoteOriginally posted by mhoule418 Quote
The picture might not be good either because there is shadow created by the lens hood!

Also consider the lens weight... For sure the Sigma 17-70 is not small.
My preferred kit is : K-3 or K-5ii (with battery grip) + Sigma 17-70, so adding a small flash is just increasing the weight, but it balances well (for me).

The Pentax AF 200FG may be a very good option to consider :
  • small and not too heavy
  • cheap
  • bring more power than the built-in unit
Im beginning to realize for me its hard to beat any of the Pentax limited prime lens. They fit everything I need but they are pricey is the only downside.
12-16-2019, 02:54 AM   #14
Junior Member




Join Date: Feb 2015
Posts: 30
Well the plastic-fantastic 35mm and 50mm are very good as well, weights next to nothing and can often be used indoors without flash because they are fast F/2.4.

Especially the 35 has found good use for me indoors, whereas the 50mm often has bit too much reach..
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
flash, im, k-mount, pentax lens, sigma, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax K-m + 50-135 + F 100 macro + sigma 17-70 + 50-150 + tamron 17-50 + metz 50 AF blem49 Sold Items 11 07-26-2013 03:25 PM
For Sale - Sold: K-5, 16-50,50-135,65-250, Sigma 17-50, 50 1.4, 50 1.8, Tamron 90 2.8, Flashes virarfast Sold Items 8 04-04-2013 02:30 PM
sigma 17-70 vs Tamron 17-50 vs Pentax 17-70 dr_romix Pentax SLR Lens Discussion 19 07-01-2012 10:15 PM



All times are GMT -7. The time now is 12:31 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top