Flash effectiveness of 85mm on DX

[carl_s]

<p>Evening all,<br>

I have a question regarding Nikon's 85mm f/1.8 prime lens. I'm considering purchasing this lens for use on a DX camera (with plans to upgrade to FX in the near to mid term future).<br>

Right now I have 35 mm and 50 mm primes. Adding the 85 would give me the telephoto end. The reviews on this lens are really good, with most saying it is a fantastic lens for portraits. If I've done my math right, the APS-C crop factor on this lens will produce a 136 mm equivalent. My concern is that at 136 mm, I might be forced to shoot from a distance that will be outside the range of my speed light. <br>

Anyone have thoughts? I'm wondering if I'd be best to stay away from the 85mm until shooting with an FX body, at which time it would be about equivalent to the 50mm that I'm using on DX right now.<br>

Thanks.</p>

[Two23]

<p>If you think you're surpassing the GN of your flash, simply ramp up ISO. You'd be surprised just how much light you can get out of those little SB flash. I think you'd be better served by a Nikon 70-200mm f2.8 if you are shooting portraits for money. Personal experience.</p>

<p>Kent in SD</p><div></div>

[mag_miksch]

<p>place the flash off the camera</p>

[User_6502147]

<p>Carl, you shouldn't have any issues getting a well exposed photo with your 85mm. I sometimes use 300mm with a flash....and most of the time all I want is a minimal touch of light and not an overkill. Sometimes I use a piece of white paper in the front of the flash...to reduce the blitz that it produces.</p>

<p>Les</p>

[Wouter Willemse]

<p>If you have a decent flash (say more or less a SB600 or up), the flash head will zoom with the lens, and at the distance a flash covers with longer focal lengths is a lot longer.If you're refering to the pop-up flash instead, then I'd get a good flash first.</p>

[Two23]

<p>Yeah, when he said "speed light" I just automatically assumed he was using something like an SB-900. I didn't even consider a pop-up flash as a speed light.</p>

<p>Kent in SD</p>

[carl_s]

<p>Thanks for the responses guys. Exactly what I was looking for. I have an SB-800 so should be OK then. I'm mainly buying it for good photos of my kids and I can pick up the 1.8D for about $300 used. Would love to have the 2.8 zoom but for a hobbyist its a bit spendy. Plus, for this hobbist, I always seem to get better photos out of my primes than the zooms. Granted I've never had the money for a pro grade zoom though. <br>

Side question - The speed light LCD shows the focal length of the lens accurately, but being that these are all FX lenses, does the flash compensate for the effective 1.6 multiplier for an APS-C sensor camera? If not, anything I should be taking into consideration to compensate?<br>

Thanks all.</p>

[rodeo_joe1]

<p>"...does the flash compensate for the effective 1.6 multiplier for an APS-C sensor camera?" - Nope!<br /> The flash zoom just reflects the actual focal length of the lens in use Carl.</p>

<p>You can either manually zoom the flash to its maximum (105mm) or just leave the automatic setting of 85mm. The difference in GN between 85mm and 105mm is absolutely minimal. In any case you should totally ignore maker's guide numbers - they're <em>all</em> invariably at least one stop optimistic. A genuine GN for the SB-800 at 85mm would be around 38 in metres (125 in ft) for 100 ISO. That still means you could be shooting at f/8 at just under 5 metres (15.5 ft) from the subject using 100 ISO. Not too shabby!</p>

<p>However, the suggestion to get the flash off-camera is the best one. There's absolutely no reason to have the flash the same distance from the subject as the camera, and Nikon's CLS makes it simple to use the camera popup flash as a trigger for your SB-800. The additional purchase of a lighting stand, speedlight adapter and a white umbrella would enable you to get beautiful light for portraits.</p>

<p>Incidentally Carl, the crop factor for Nikon's DX format from full-frame is only 1.5x. Canon's slightly smaller DX format has a factor of 1.6. So an 85mm lens on Nikon DX has the same angle-of-view as a 127.5mm lens on FF.</p>

[carl_s]

<p>Joe,<br>

Wonderful information. Thank you. I am always impressed by the intelligent responses from Photo.net users. If only all forums were so helpful... Happy holidays all. </p>

[john_curlett]

<p>"...does the flash compensate for the effective 1.6 multiplier for an APS-C sensor camera?" - Nope!</p>

<p>I don't know about the SB-800 but the later model Nikon flashes like my SB-700 have FX and DX modes which can be manually selected or the flash can detect the type of camera attached. In the DX mode, the flash zooms to provide a narrower area of illumination for a given focal length than it does in the FX mode. For example with an 85mm lens, in DX mode the angle of illumination is 17 X 24 degrees where it is 23 X 31 degrees in the FX mode. I am referring to page H-20 of the SB-700 manual.<br>

Check your manual. The SB-800 may be the same.</p>

[rodeo_joe1]

<p>The SB-800 has no DX mode John, and can't zoom narrower than 105mm on FX (20V x 27H degrees).</p>

<p>In any case, even on the SB-700, the supposed narrowing of coverage angle doesn't produce a corresponding increase in Guide Number. At maximum it's reported as 38 (metres/100 ISO) in Nikon's manual. That's probably more like a real and measurable GN of 27.</p>

[john_curlett]

<p>Joe - As I said I wasn't about the SB-800. I did a quick check with my SB-700 with the zoom set at 85mm and got a GN of 30 on FX and 33 on DX so there is a little improvement going to DX. I had never really measured it before.</p>

[owen_omeara]

<p>I own the lens and am more than happy with it on both my d7100 and d810. It is very good as a portrait lens on both cameras but a slight cut below the 105 2.8 on the d810.</p>

<p>-O</p>

[richard_barron]

<p>I haven't made a direct-flash image on purpose since high school.<br>

http://richardbarron.net/cameras/2014/02/03/worst-lighting-ever/</p>

[Wouter Willemse]

<p>Carl,</p>

<blockquote>

<p>...the 1.8<strong>D</strong> for about $300 used....</p>

</blockquote>

<p>Please do note that the 1.8<strong>D</strong> isn't exactly the 1.8<strong>G</strong> that you will read about most these days. Opinions on the older D lens are a lot less unanimous, but in all cases, you will find less praise. Mine is a good lens, especially stopped down; wide open it's not as good and its colour rendering isn't the most pleasing I know of. Others here have had less luck. Anyway, the 1.8D isn't among the great lenses by any stretch of imagination.</p>

<p>The 1.8G is easily worth the extra money in my view. Go for the newer one, if you can; in every test, it looks to be a much better lens and the results I see from it rival the 85 f/1.4G even. It's not a whole lot more expensive than the D version, so it's worth saving up for.</p>

[rodeo_joe1]

<p>I can't agree more with what you've written on your website Richard. Perhaps someone should pass that information on to the current "rat pack" of top fashion photographers (and their many imitators).</p>

[Two23]

<p> Richard is very down on the pop-up flash. I agree that almost always an off-camera flash gives better results, but I do like the convenience of the pop-up for quick jobs when I don't really need a high quality shot. It also works when I need just a tiny amount of fill.</p>

<p>Kent in SD</p>

[carl_s]

<p>Kent - I agree. While I would love to learn how to use off camera lighting, most of my photos are candids of my kids at events (where I barely have enough time to turn my camera on let alone set up off camera equipment). For me, the deciding factor between Canon and Nikon was the integrated flash on full frame bodies. Something is often better than nothing. <br>

What I really need is a resource on how to make the best of a bad situation - that is techniques to improve photos when using my SB-800 on camera. </p>

[Wouter Willemse]

<p>Carl, I've found <a href="http://neilvn.com/tangents/flash-photography-techniques/">these tutorials</a> quite useful for "direct flash" usage and techniques.</p>

[carl_s]

<p>Thanks WW. Will take a look.</p>

[richard_barron]

<p>One big reason I come down so hard on direct flash, and pop-up flash in particular, is to discourage my students, many of whom just bought their first DSLR and know little about it, from letting the camera take over and pop up that flash when it gets dark. They need to learn a drillion better lighting solutions before they come back around to any kind of creative efforts with direct flash.</p>

[rodeo_joe1]

<p>Carl, you can usually find a suitable surface to 'bounce' the flash off. Bouncing effectively gets the light source off camera without the flash actually being off camera. It also softens the light nicely.<br>

Bounce flash is no longer limited to white surfaces with a DSLR either. A cream or slightly blue wall or ceiling is no problem at all to correct using the camera's WB control. I've even bounced flash off an "insanity yellow" painted wall and been able to correct the colour by use of a custom WB.</p>

<p>No need to follow the commonly held belief that the flash needs to be pointed to reflect from a wall or ceiling as if it was a mirror. A matt surface will spread light equally in all directions, so you just choose a spot to bounce from where the direction will light the subject nicely.</p>

[richard_barron]

<p>Rodeo Joe, I agree with that completely. I used an off-white blanket as a bounce target for this image of my wife. It created incredibly natural-looking light...</p>

<p><img src="http://richardbarron.net/cameras/wp-content/uploads/2010/01/abby-dec-09-a1.jpg" alt="" width="437" height="648" /></p>

[carl_s]

<p>Since the thread topic is wandering a bit...<br>

I have experimented with bounce flash previously and never spent the time to really understand how to use it appropriately. I just took a few snapshots in the house and am wondering how much I should be trusting the camera's exposure meter. What is confusing me is the balance between camera exposure and flash exposure. <br>

Should I be trusting the meter on the camera for the background and then be adjusting flash exposure for lighting of the foreground? It seems like a somewhat delicate balance that could have a million successful combinations.<br>

Also, if I am using a bounce flash, should I be leaving the flash in TTL or manually setting the flash zoom as wide as possible (I think 24mm)?</p>

[richard_barron]

<p>Carl, my apologies for getting off-topic. To bring it back a bit, my 85mm f/1.8 AF of 1993 vintage just died. It wasn't the greatest lens in my bag. Those advising you to consider the AF-S version are correct. It's a much better item.<br>

Regarding bounce flash: I almost always shoot in manual mode so I can finesse the mix of flash and ambient light as needed. The above image mixes flash from an older SB-24 in 1/2 power manual, bounced off a blanket, with a desk lamp over her shoulder to highlight her hair. It took just a couple of test frames to get the balance right. In the first frame or two I wasn't getting the golden highlights I wanted, so I changed to a longer shutter speed to bring them out without effecting the exposure from the flash.</p>