Close

Loading image...
Pentax K-01
35 Images + 4 Videos

Pentax K-01 Digital Camera

MILC 16.28MP CMOS Apr 2012
Camera Type Megapixel Count Image Stabiliser Sensor Type Release Date
Exceptional Image Quality Assured By Digital SLR Camera SystemThe PENTAX K-01 comes equipped with a newly developed CMOS image sensor measuring 23.7 millimeters by 15.7 millimeters. With... More
Available from international sellers only
Tell Me When It Becomes Available
You are subscribed to price alerts for this product
Unsubscribe
Searching for international prices ...

Assumed Exchange Rates

Searching for prices in ...
Pentax K01 and Q AF test
Pentax k01 video outdoor test
Pentax K01 Video Test Muted vs Natural
Pentax K01 Video Test

30 Reasons For

Good Owner Reviews

Based on 107 owner reviews this camera has an average owner rating of 89%.

Good Video Capture

A few people mentioned in their reviews that the product was good for video recording. Dr. M. Z. Aung said on Amazon “Full HD video recording capability”. Three years ago Icewalker wrote on Amazon “Very impressed with the photo results and videos are great too!Recomended” and gave it a rating of 5 stars. Nr said in their Pentax K-01 review on Amazon also three years ago “It produces nice video with acceptable sound, plus the ability to add an external microphone”.

Good Quality Lens

Some Pentax K-01 reviewers who reviewed it thought it had a good lens. John mentioned two years ago “The bundled 18-55mm lens is good” but even so he scored the product 60 out of 100. Three years ago Nr gave this digital camera a rating of 5 stars and said on Amazon “A wonderful camera, works (ie provides focus confirmation and anti-shake) with every Pentax lens ever made, plus plenty of others (eg I have a microscope adapter”. Four years ago Reviewed.com wrote in their review of this digital camera “Excellent photos quality (assuming your lens works properly”.

Some people considered that it had a good autofocus. John mentioned in his review of the Pentax K-01 “The big limitation of this camera is the autofocus which is unreliable” nonetheless he rated this digital camera 3 stars. Mark Bowerbank mentioned “It's possible to make precise focusing decisions”. N. Topham mentioned on Amazon three years ago “Quick to focus”.

One Pentax K-01 owner said in their reviews that it had a good image stabiliser.

Read more Less

Good Quality Pictures

A number of people who purchased it considered that it was able to produce good images. A. C. Yelmo wrote “Nearly all the cameras in the world, as you can easily check googling images for "on-off dial") had the controls inverted”. Barso wrote “Sometimes it can take great photos with the pancake” in their review of the Pentax K-01. Boatbuilder Man said on Amazon three years ago “Takes perfectly good pictures most of the time” in their review.

Some customers considered that it was good in low light. Three years ago A. C. Yelmo said “The low light sensitivity is great” in their review of this digital camera however despite that they gave the Pentax K-01 a rating of 60 out of 100. N. Topham scored it very highly and said in their review of this digital camera on Amazon “I had a Pentak K-7 and the improvment in image quality and low light performance quickly promoted this to the camera of choice”. Nr mentioned “Good in low light too”.

Two Pentax K-01 owners who bought it agreed that it had a good picture resolution. Dr. M. Z. Aung said “The PENTAX K-01 is an interchangeable lens camera with super-high-resolution image quality supported by approximately 16.28 effective megapixels” in their review of the Pentax K-01.

One Pentax K-01 owner considered that this digital camera had a good ISO range. Four years ago Reviewed.com wrote “Excellent high ISO performance”.

Read more Less

Easy to Use

Several Pentax K-01 owners who reviewed this digital camera concluded that it was easy to use. A. C. Yelmo said in their review of the Pentax K-01 on Amazon three years ago “I found that sometimes it was easier to use the thumb to press the shutter button” but despite that they only gave the Pentax K-01 a score of 3 stars. In the same month Mark Bowerbank gave the product an excellent rating and he said in his review of the Pentax K-01 on Amazon “It handles well an all the controls have a quality, precise feel about them, despite it being somewhat heavier than the alternative mirrorless system cameras available today”. Mark Bowerbank also mentioned “This camera will give you spectacular creative control”.

One Pentax K-01 owner who reviewed it thought it was easy to use the menus. Paul Taylor gave the product a very good review score and he said on Amazon “Excellent product, very nicely made, produces excellent quality photographs however I think best used in one of the manual mode settings, Amazon provided a fast efficient service” in his review of the Pentax K-01.

One customer who reviewed the product concluded that it had a good interface. A. C. Yelmo said on Amazon “It is not a flagship model; so it's understandable that it has a simpler interface”.

Read more Less

Robust

Ten customers mentioned in their reviews that the Pentax K-01 was well made. Icewalker mentioned on Amazon “If you like a big solid camera” and scored it 5 stars. Marco mentioned on Amazon “Great image quality and solid body” and rated it 5 stars. Three years ago Mark Bowerbank mentioned in his review on Amazon “The 18-55mm kit lens is a solid all-rounder”.

One Pentax K-01 owner who reviewed this digital camera thought it was strong and durable.

Read more Less

Nice Design

A few people wrote in their reviews that it was a good design. Three years ago A. C. Yelmo wrote on Amazon “Award winning design? Really?” but even so they only gave the product a score of 3 stars. A. C. Yelmo also mentioned “A good design should focus on prevent turning the camera on accidentally”. Dr. M. Z. Aung wrote on Amazon “Pentax K-01 Wins Red Dot Design Award” in their Pentax K-01 review.

A few customers who reviewed this digital camera said that it was good looking. A. C. Yelmo wrote on Amazon “The result a trendy designer's bloated ego” nonetheless they only gave this digital camera a score of 60 out of 100. Pan Ke said in their review of this digital camera “Good looking”. Pentax said on Amazon “After some months of using it camera still impresses with elegant design, general robustness”.

Read more Less

Good Product Quality

Twenty-nine customers who bought the Pentax K-01 reckoned that it was good quality. Bg mentioned in their review of this digital camera “Excellent image quality- good pancake lens- k-mount camera- focus peaking (makes manually focusing easily)- long battery life- very well built body- nice design” . Darkmunk rated this digital camera 4 stars and mentioned in their review “Job done! The picture quality, dynamic range”. Dr. M. Z. Aung mentioned four years ago “The award - the red dot - has established itself internationally as one of the most appreciated quality seals for outstanding designs” and gave the Pentax K-01 a score of 5 stars.

Reasonably Priced

Eight Pentax K-01 owners thought it was good value for money. Ann mentioned “The feature set is wonderful for the price and it looks nuts” in her review of this digital camera and gave the Pentax K-01 a rating of 5 stars. Darkmunk wrote on Amazon “Got it for high quality at a good price” and gave it a score of 80 out of 100. John wrote two years ago “I bought this (fortunately at a good price as a daily deal) thinking I could dust off my old lenses with the Pentax K mount” in his Pentax K-01 review.

Some customers who reviewed the product agreed that it was a bargain for the price. Two years ago Ann mentioned “What a bargain (after it halved in price” in her review of this digital camera. Jukeboxjohnnie said “Pentax have just discontinued it after only a year so a potential collectable, best got 'manufacturer refurbished' a bargain price if you look around” in their Pentax K-01 review. Nr scored this digital camera 5 stars and said on Amazon “I just can't believe I purchased a camera this good so cheaply”.

Read more Less

Pentax Cameras Have Excellent Reviews

Based on 1,276 owner and expert reviews, Pentax has excellent ratings for its digital cameras. Pentax also has excellent ratings specifically for its MILC digital cameras compared to other brands.

Chart

Good Battery Life

Some Pentax K-01 reviewers who reviewed it reckoned that it had a good battery life. Mark Bowerbank wrote in his Pentax K-01 review on Amazon three years ago “The battery life is good (easily enough for 300+ shots)”. Stu wrote also three years ago “Battery life was good.” and gave this digital camera a rating of 80 out of 100.

Acceptable Noise Level

Four Pentax K-01 reviewers who purchased it agreed that it was noisy. Van he wrote in his review of this digital camera “Excellent photos quality; low noise through ISO 1600 in low light”.

One customer said in their reviews that the Pentax K-01 was quiet. Two years ago Ann said in her review of this digital camera “The autufocus is very very noisy on the kit lens so if you need quiet put on an old Takumar or Helios”.

Read more Less

Good Technical Features

A number of Pentax K-01 reviewers mentioned that it had good features.

Good Flash

One person wrote in their reviews that it had a good flash.

Good Support

A few people who purchased it said that it had good technical guidance. Mickey_annie said “Manual mode easy to handle; need to buy other lens”. Van said in his review of this digital camera “Image stabilization Powerful flash (for an ILC) Stereo mic input Best-in-class battery life Full, printed manual in the box (a rarity these days” .

Full HD HD Type

The HD type of this camera is Full HD, which is the most frequently found HD type on MILC digital cameras that have been available for around the same time as it.

Chart Edit

Supports Video Recording

supports video recording

The Pentax K-01 supports video recording. Most of the other MILC digital cameras that were released around the same time as the K-01 do not support video recording.

There are a number of other cameras which support video recording currently available which you might also want to look at including the Sony NEX-7[plb_1612397_price], or the Panasonic Lumix DMC-GF3[plb_1869201_price] which has better reviews.

Read more Less Chart Edit

Has a Built-In Flash

has a built-in flash

The Pentax K-01 has a built-in flash. Most of the other digital cameras of this age and spec also have a built-in flash.

We compared all the other cameras with a built-in flash to this digital camera and we think the Panasonic Lumix DMC-GH3[plb_1815297_price], and the Samsung NX Mini NXF1[plb_2266348_price] which has better reviews is also worth considering.

Read more Less Chart Edit

Supports Full HD Video

supports Full HD video

The Pentax K-01 supports Full HD video, as do most of the other cameras of a comparable type and age to the K-01.

Other digital cameras which support Full HD video currently available which you might want to look at include because of it's better review score, the Nikon 1 J3[plb_1858479_price].

Read more Less Chart Edit

SD Memory Card

This camera supports an SD|SDHC|SDXC memory card, which is typical of many digital cameras of a similar spec and age to it. SD cards are by far the most common type of memory card. They are compatible with the majority of digital cameras.

Other digital cameras that support an SD|SDHC|SDXC memory currently available that you might also want to consider include the Samsung NX300M[plb_2205970_price], the Panasonic Lumix DMC-GH4[plb_2173892_price], or the Nikon 1 AW1[plb_2020636_price] which has better reviews.

Read more Less Chart Edit

MOS Sensor Type

This digital camera has a CMOS sensor type, which is typical of many MILC digital cameras that have been available for a similar time to it.

Chart Edit

Supports Two Image Formats

The number of supported image formats on the Pentax K-01 is more than most MILC digital cameras that came out more than two years ago. This digital camera supports a JPG image format, which is the most commonly supported image format supported by digital cameras that have been on the market for a similar time to the K-01. The image format "RAW" is also supported by this Pentax digital camera.

Chart Edit

Electronic Camera Shutter

This digital camera has an Electronic camera shutter, which is typical of many MILC digital cameras that have been around for a similar time to it.

Chart Edit

Fairly Small Maximum Aperture

The Pentax K-01 has one of the smaller maximum apertures (22) amongst comparable spec digital cameras of this age. Across all the digital cameras of this age and type the maximum apertures range from 1 to 36, and the average maximum aperture is 14.

Chart Edit

540 Shots Per Battery Charge

Most MILC digital cameras that are a comparable age to the K-01 take between 220 and 649 shots per battery charge, including the Pentax K-01 which takes 540 shots per battery charge.

Chart Edit

Has Eight White Balance Modes

The number of white balance modes found on the Pentax K-01 is more than most comparable spec cameras that have been available for more than two years. The most frequently found white balance mode is Auto, but this white balance mode is not found on this Pentax camera. The white balance modes Cloudy, Daylight, Fine, Flash, Fluorescent, Manual, Shade and Tungsten are also found on this camera.

Chart Edit

Has One Image Editing Mode

The number of image editing modes found on the Pentax K-01 is more than most MILC digital cameras that have been on the market for more than two years. This camera has a Rotating image editing mode, which is the most frequently found image editing mode found on digital cameras of a comparable age and type to the K-01.

Chart Edit

1920 X 1080 Pixels Video Resolution

This digital camera supports a video resolution of 640 x 480|1280 x 720|1920 x 1080 pixels, which is typical of many digital cameras of this age and spec. A video resolution of 1920 x 1080 pixels is equivalent to Full HD video. You will require a Full HD TV or better to appreciate this level of detail.

Chart Edit

TFT Display

The Pentax K-01 has a TFT display which is better than the LCD display found on most cameras of a similar spec and age to it. TFT LCDs provide better image quality and higher resolutions to earlier LCD displays but their limitations are narrow viewing angles and poor vislibility in direct sunlight. Across all cameras of a similar type and age to the K-01 the best display is AMOLED and the worst is LCD.

Chart Edit

Supports One Power Source

The Pentax K-01 has a greater number of power sources than most MILC digital cameras that have been around for a similar time to it. This digital camera supports a Battery power source, which is the most commonly supported power source supported by cameras of a comparable age and spec to the K-01.

Chart Edit

11 Reasons Against

Not Good in Terms of Size

A few people who bought the product reckoned that it was not heavy and bulky. John rated the product 3 stars and he said in his review of the Pentax K-01 on Amazon two years ago “I quickly concluded that such heavy lenses belonged to a previous era”. Mark Bowerbank said on Amazon “Superb picture quality from "The Chunky One”. Three years ago Penelope Polins mentioned “What a lovely camera to use, if a little heavy” in her review of the Pentax K-01.

Two Pentax K-01 owners who bought it reckoned that it was not a good body shape. Reviewed.com wrote four years ago “Questionable quality control for body and lenses” in their review of the Pentax K-01. Reviewed.com also mentioned “Noisy autofocus isnt fast enough, no viewfinder possible, large body size, lack of prominent grip”.

One Pentax K-01 reviewer who bought it considered that it was not thick. Three years ago Darkmunk said in their Pentax K-01 review “It will easily slip into a loose pocket” although they rated the product 4 stars.

Read more Less

Does Not Support WiFi Connectivity

The Pentax K-01 does not support WiFi connectivity. Most of the other digital cameras that have been on the market for a comparable time to the K-01 also do not support WiFi connectivity.

We compared all the other cameras which also support WiFi connectivity to this digital camera and we think the Panasonic Lumix DMC-GM1[plb_2070627_price] which also has a higher rating is also worth considering.

Read more Less Chart Edit

Not 3D Compatible

Most MILC digital cameras that came out around the same time as the K-01 are not 3D compatible. The Pentax K-01 is no exception to this as it too is not 3D compatible.

If you would prefer a camera that is 3D compatible then you might want to consider the Samsung NX20[plb_2083247_price] which also has a higher rating.

Read more Less Chart Edit

Does Not Have a GPS

The Pentax K-01 does not have a GPS. Most of the other similar spec cameras that have been on the market for a comparable time to the K-01 also do not have a GPS.

Other digital cameras which also have a GPS that you might also want to consider include the Samsung Galaxy NX[plb_2082510_price] which also has a higher rating.

Read more Less Chart Edit

Not Waterproof

Like most of the other cameras of a similar age and spec to the K-01, the Pentax K-01 is not waterproof.

Chart Edit

Does Not Have an Image Stabiliser

Most digital cameras of a comparable spec and age to the K-01 do not have an image stabiliser. The Pentax K-01 is no exception to this as it too does not have an image stabiliser.

Chart Edit

Only Supports Two Camera File Systems

The Pentax K-01 has a greater number of camera file systems than most MILC digital cameras that have been available for more than two years. This Pentax digital camera supports an Exif 2.3 camera file system, which is the most commonly supported camera file system supported by MILC digital cameras that have been around for more than two years. The camera file system "DCF 2.0" is also supported by this camera.

Chart Edit

Only 1728 X 1152 Still Image Resolution

The Pentax K-01 has a 1728 x 1152 still image resolution which is higher than the 1920 x 1080 still image resolution found on most similar spec cameras that were released more than two years ago. In addition, this camera have a still image resolution of 3072 x 2048 and 3936 x 2624. Across all MILC digital cameras that have been around for a similar time to the K-01 the worst still image resolution is 1024 x 768 and the best is 12416 x 1856.

Chart Edit

Only Features One Image Adjustment Mode

The number of image adjustment modes featured on the Pentax K-01 is more than most MILC digital cameras that have been around for around the same time as it. The most frequently featured image adjustment mode is Contrast, but this image adjustment mode is not featured on this camera. The image adjustment modes Brightness are also featured on this Pentax camera.

Chart Edit

Heavy

The lightest digital camera of a similar type and age to the K-01 is 70g , the heaviest is 680g, and the average weight is 310g. The Pentax K-01 is quite heavy (480 grams) compared to most of the other digital cameras of a comparable age and spec to the K-01.

Digital cameras with a heavier weight that might be worth looking at include the Leica M9-P[plb_1336647_price] (600g).

Read more Less Chart Edit

Thick

At 59 millimeters, the Pentax K-01 is fairly thick compared to most of the other MILC digital cameras that have been around for around the same time as the K-01. Comparable spec cameras that are a similar age to the K-01 have depths of between 22mm and 95mm.

Chart Edit

3 Other reasons to consider the Pentax K-01

Released Over Four Years Ago

It was over four years ago when this camera was released.

Average Screen Size

With a screen size of 3 inches, the Pentax K-01 has a relatively average screen size compared to most of the other digital cameras of this type and age.

We compared all the other 3" screen cameras to this digital camera and we think because of it's better review score, the Panasonic Lumix DMC-GH3[plb_1815297_price], and the Pentax Q7[plb_2058121_price] is also worth considering.

If you would prefer a camera with a larger screen size then you might want to consider the NX300[pl_2096674_price] (3.31"), the NX300M[pl_2205970_price] (3.31"), or the NX2000[pl_2085238_price] (3.7") all from Samsung which also has a higher rating.

Read more Less Chart Edit

Average Megapixel Count

The Pentax K-01 has a pretty typical megapixel count (16.28 megapixels) compared to most of the other digital cameras that have been available for around the same time as the K-01.

If this camera megapixel count is too low for you then you might want to look at the Leica T (Typ 701)[plb_2550905_price] (16.3MP), or the Fujifilm X-M1[plb_2032322_price] (16.3MP) which also has a higher rating.

Read more Less Chart Edit

Specification

Picture Quality
Camera Type
Megapixel Count
Image Stabiliser
Sensor Type
Still Image Resolution
Maximum Image Resolution
Aspect Ratio
Image Format
Full-Frame Sensor Size
Aspect Ratio
Design
Colour
Lens System
Maximum Aperture
Minimum Aperture
Focal Length Range
Fixed Focal Length
Lens Structure
Focusing
Auto Focus
Light Exposure
Light Exposure Mode
ISO Speed
Maximum ISO Speed
Minimum ISO Speed
Light Metering Mode
Light Exposure Correction
Light Exposure Control
Shutter
Maximum Camera Shutter Speed
Minimum Camera Shutter Speed
Camera Shutter
Flash
Flash Mode
Video
Full HD Video
Maximum Video Resolution
JPEG Frame Rate
Video Format
Analog Signal Format
Video Resolution
Video Recording
HD Type
Audio
Built-In Microphone
Voice Recording
Memory
Memory Card
Memory Slot
Display
Screen Size
Display
Display Resolution
Ports & Interfaces
AV Output
DC-In Jack
HDMI Port
HDMI Connector
USB Version
Camera
White Balance Mode
Self-Timer
Calendar
Album Organization
Histogram
Image Adjustment Mode
Image Editing Mode
Camera File System
Tripod Mount
Playback Mode
Contrast Adjustment
Scene Mode
On Screen Display Language
Weight & Dimensions
Weight
Height
Depth
Width
Weight Including Battery
Battery
Power Source
Battery
Supported Battery
Battery Size
Shot Per Battery Charge
System Requirements
Mac Compatible
Packaging Content
Included Cable
Battery Included
Included Battery Charger
Hand Strap
Other Features
Video Recording
Built-In Flash
USB 2.0 Port
HDMI Port
Interface
On/off Switch
Frame
Camera Shutter Speed Range

Expert Reviews

13 June 2012

Sections...

Good image quality
Compatible with K, mount lenses
Good build quality
Wide viewing angle LCD
Compatible with Kmount lenses
Advertisement var erA document
CreateElement('iframe')
ErA
SetAttribute("id", "")
SetAttribute("src", "http
13 December 2014

Unsere Kamera-Tests bieten zwar Orientierung bei der Auswahl der richtigen Kamera. Doch am Ende entscheidet der User selbst, welches Modell es für ihn sein soll. Welche Digicams derzeit besonders... Read more…

Features
Image quality
Available lens range
Interesting and useful design
Produces vibrant and clear image
Handling
Design problems
Lowlight focusing
Dynamic range not great
Fixed screen position

User Reviews

(30)
Reviewed 18 June 2014 by Ann
(Verified Purchase)

What a bargain (after it halved in price). The IQ is wonderful, the feature set is wonderful for the price and it looks nuts. I would have preferred the yellow model but i went for classic... Read more…

Reviewed 5 February 2014 by John
(Verified Purchase)

I bought this (fortunately at a good price as a daily deal) thinking I could dust off my old lenses with the Pentax K mount. I did, and they work (of sorts), but I quickly concluded that such... Read more…

Reviewed 26 December 2013 by Mark Bowerbank
(Verified Purchase)

This camera is a revelation. Wherever it goes people ask "What is it?" and inevitably, "Where's the viewfinder?". All I can say is if you can forgive the K-01 for its size and the... Read more…

Reviewed 12 December 2013 by DT Coventry
(Verified Purchase)

This was the reason I held on to the lenses from my Pentax MZ50 film camera. I'm so pleased with this camera, and the quality of the images it produces.

Reviewed 18 October 2013 by Stefan 22 | 2 Comments
(Verified Purchase)

The first thing to be said is that the camera bought (with 18-55mm lens) has a picture quality that is (I highly suspect) far superior by comparison to all its similarly priced competitors. I know... Read more…

« Prev 1 of 6 Next »

+- Manufacturer's Description

Product Identifiers

Manufacturer Part Numbers pentax k01, pentax k01w, pentax k01z, pentax k01b, pentax k01bo, pentax k01wz, pentax 15423, pentax k01zk, pentax 15372, pentax k01bod, pentax k01wzk, pentax k011855, pentax k01body, pentax k011855y, pentax k01bodyk, pentax k011855yw, pentax k01bodyki, pentax pentaxk01, pentax k01lensbod, pentax pentaxk01b, pentax k01bodykit, pentax k01bodykitb, pentax k01lensbody, pentax pentaxk01by, pentax k01bodykitbl, pentax k01lensbodyk, pentax k01bodykitbla, pentax k01lensbodyki, pentax k01bodykitblac
Barcodes 00027075214583, 00027075214590, 00027075214699, 00027075214804, 00027075214811, 00027075215306, 00027075215320, 00027075215436, 00027075215535, 00027075215634, 00027075215740, 00027075215849, 00027075215948, 00027075216143, 00027075216242, 00027075216259, 00027075216266, 00027075216273, 00027075217119, 00617689591479, 04549212215452, 04549212216060, 04549212216220, 05052415400406, 05473543147399

Save Money with These Great Digital Camera Vouchers & Offers

£30 Off
Voucher
£30 Off a £300+ spend
Valid 1 Nov 16 - 31 Jan 17
20% Off
Voucher
20% Off over £80
Valid until 31 Dec 16
15% Off
Voucher
15% Off for new customers
Valid 17 Mar 16 - 17 Mar 17
8% Off
Voucher
GearBest Consumer Electronics Coupon_ 8% OFF
Valid 6 Aug 16 - 31 Dec 16

See How Other Digital Cameras Compare to the Pentax K-01

Olympus OM-D E-M5 vs Pentax K-01

Olympus OM-D E-M5 vs Pentax K-01
Olympus OM-D E-M5 Pentax K-01
£ 295.00
"Expert Reviews" Review is Significantly Better
Pocket Lint Review is Significantly Better
Techradar Review is Significantly Better
Digitaltrends.com Review is Significantly Better
Only Live MOS Sensor
Older USB Version

Olympus OM-D E-M1 vs Pentax K-01

Olympus OM-D E-M1 vs Pentax K-01
Olympus OM-D E-M1 Pentax K-01
£ 525.00
Vastly Better "Trusted Reviews" Review
Vastly Better Digitaltrends.com Review
Vastly Better PC Mag Review
Vastly Better Digital Versus Review
Half As Good Display
Worse Sensor Type

Fujifilm X-E1 vs Pentax K-01

Fujifilm X-E1 vs Pentax K-01
Fujifilm X-E1 Pentax K-01
£ 399.00
Thirteen More Awards
Hugely Better Review from Photo Answers.co.uk
Hugely Better Review from Digital Versus
Hugely Better Review from Techradar
Lower Display Resolution
Bigger Maximum Aperture
Feedback